UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Methylmercury exposure in British Columbian anglers who consume both recreationally caught and commercially… Kodama, David Michael Yuko 2011

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
24-ubc_2011_fall_kodama_david.pdf [ 4.94MB ]
Metadata
JSON: 24-1.0102581.json
JSON-LD: 24-1.0102581-ld.json
RDF/XML (Pretty): 24-1.0102581-rdf.xml
RDF/JSON: 24-1.0102581-rdf.json
Turtle: 24-1.0102581-turtle.txt
N-Triples: 24-1.0102581-rdf-ntriples.txt
Original Record: 24-1.0102581-source.json
Full Text
24-1.0102581-fulltext.txt
Citation
24-1.0102581.ris

Full Text

Methylmercury Exposure in British Columbian Anglers Who Consume Both Recreationally Caught and Commercially Bought Fish  by David Michael Yukio Kodama  B.M.Sc., The University of Western Ontario, 2007  A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES (Occupational and Environmental Hygiene)  THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver)  July 2011 © David Michael Yukio Kodama, 2011  Abstract 
 Methylmercury is a common contaminant found in fish. Chronic exposure can have detrimental effects on the nervous, cardiovascular and immune systems. Since mercury exposure can come from consuming fish that is caught as well as fish that is purchased, recreational anglers are a group that may have higher exposure than non-anglers. It was the primary goal of this study to determine whether exposure to methylmercury in Vancouver Island recreational anglers was greater from the consumption of sport-fish or from commercial fish. Study participants were recruited from the BC Ministry of Environment freshwater fishing license list. A comprehensive questionnaire was administered over the telephone to enumerate potential sources of exposure to methylmercury. While the questionnaire primarily focused on the frequency, mass and species of fish consumed, other exposure sources were also examined. Following the questionnaire, a blood sample was collected and analyzed for mercury. A total of 195 anglers between the ages of 21 and 85 participated in the study. 80% of the subjects were male and approximately 90% were born in Canada. The geometric mean bloodmercury concentration was 2.33 ± 2.16 µg/L. In multiple regression analysis, the consumption of caught rockfish, shellfish and cutthroat trout as well as bought fresh/frozen albacore tuna, fresh/frozen ‘other’ tuna, i.e. ahi, skipjack or yellowfin, and snapper were found to be the greatest predictors of exposure. The results of this study demonstrated that exposure to methylmercury in Vancouver Island anglers was equally distributed between recreational and commercial fish species. The observed blood-mercury concentrations were consistent with similar studies, as was the discovery that it was primarily the frequent consumption of fish species containing low to moderate amounts of mercury that drove exposure. While this study determined that three recreational and three commercial fish species were predictors of exposure, five of these six were saltwater species while the sixth, cutthroat trout, was anadromous. Future studies should therefore focus on evaluating the differences in exposure between fresh and saltwater fish consumption.  In  addition, conducting a comprehensive survey of tissue-mercury levels in Vancouver Island fish would provide valuable region-specific data, leading to better exposure estimates in anglers. ii
  Preface 
 This study involved the administration of a questionnaire as well as the collection of a blood sample, both of which required research ethics approval. The University of British Columbia Clinical Research Ethics Board approved all study procedures. The certificate number for this study was H09-01544 and is available through the University of British Columbia’s Office of Research Services.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  iii
  Table of Contents Abstract.......................................................................................................................................... ii Preface........................................................................................................................................... iii Table of Contents………………………………………………………………………………………………..iv List of Tables ............................................................................................................................... vii List of Figures............................................................................................................................... ix Acknowledgements ....................................................................................................................... x 1. Introduction............................................................................................................................... 1 1.1 The Risks and Rewards of Fish Consumption ............................................................................... 1 1.2 Recreational Fishing on Vancouver Island .................................................................................... 2 1.3 Mercury ............................................................................................................................................. 2 1.3.1 Environmental Sources of Mercury............................................................................................. 3 1.3.2 Methylmercury in Fish and in Humans ....................................................................................... 4 1.4 Health Effects of Methylmercury Exposure................................................................................... 5 1.5 Mercury Concentrations in Canadian Fish.................................................................................... 7 1.6 The Effect of Fish Consumption Frequency and Fish Portion Size on Mercury Exposure....... 9 1.7 Public Fish Consumption Guidelines ............................................................................................ 10 1.7.1 Canadian Fish Consumption Guidelines ................................................................................... 10 1.7.2 British Columbia Fish Consumption Guidelines....................................................................... 11 1.8 Evidence of Methylmercury Exposure from the Consumption of Fish ..................................... 12 1.9 Demographics and Patterns of Mercury Exposure ..................................................................... 17 1.10 Summary and Gaps in the Literature......................................................................................... 19 1.11 Study Rationale ............................................................................................................................. 21 1.12 Study Objectives and Hypotheses ............................................................................................... 21  2. Methodology ............................................................................................................................ 23 2.1 Study Population............................................................................................................................. 23 2.2 Subject Recruitment ....................................................................................................................... 24 2.3 Research Package Documents ....................................................................................................... 27 2.3.1 Consent Form ............................................................................................................................ 27 2.3.2 Study Instructions ...................................................................................................................... 28 2.3.3 Questionnaire Materials............................................................................................................. 28 2.3.4 Requisition Forms ..................................................................................................................... 29 2.4 Questionnaire Design...................................................................................................................... 29 2.4.1 Section A ................................................................................................................................... 29 2.4.2 Section B ................................................................................................................................... 29 2.4.3 Section C ................................................................................................................................... 30 2.4.4 Section D ................................................................................................................................... 31 2.4.5 Section E.................................................................................................................................... 32 2.4.6 Section F .................................................................................................................................... 33 2.4.7 Questionnaire Pilot .................................................................................................................... 33 2.5 Data Collection ................................................................................................................................ 34 2.6 Data Analysis................................................................................................................................... 35 2.6.1 Categorization of Fish Species .................................................................................................. 35 2.6.2 Coding of Fish Consumption Variables .................................................................................... 35 2.6.3 Coding of the Subject’s and Subject’s Parents’ Country of Birth............................................. 36  iv
  2.6.4 Descriptive Statistics and Bivariate Analyses ........................................................................... 37 2.6.5 Multiple Linear Regression ....................................................................................................... 38 2.7 Subject Follow-Up........................................................................................................................... 38  3. Results ...................................................................................................................................... 40 3.1 Blood-Mercury Concentrations..................................................................................................... 41 3.2 Study Population............................................................................................................................. 42 3.2.1 Characteristics of the Study Sample.......................................................................................... 42 3.2.2 Blood-Mercury Concentrations and Demographic Variables ................................................... 46 3.2.3 Total Recreationally Caught Fish Consumption and Demographic Variables ......................... 48 3.2.4 Total Commercially Bought Fish Consumption and Demographic Variables.......................... 50 3.3 Recreational Fishing Frequency.................................................................................................... 51 3.4 Portion Size and the Frequency of Total Fish Consumption: Caught and Bought .................. 52 3.4.1 Portion Size ............................................................................................................................... 52 3.4.2 Frequency of Total Fish Consumption: Caught and Bought..................................................... 53 3.4.3 Aggregation of Portion Size and the Frequency of Fish Consumption..................................... 54 3.5 Species-Specific Fish Consumption: Caught and Bought ........................................................... 55 3.5.1 Recreationally Caught Fish Consumption................................................................................. 55 3.5.2 Commercially Bought Fish Consumption ................................................................................. 56 3.5.3 Blood-Mercury Levels and Consumption of Individual Fish Species ...................................... 60 3.6 Other Exposure Information ......................................................................................................... 61 3.7 Multiple Linear Regression............................................................................................................ 64 3.7.1 Correlation ................................................................................................................................. 64 3.7.2 Criteria for Inclusion into the Model......................................................................................... 65 3.7.3 Multiple Linear Regression Model............................................................................................ 65  4. Discussion ................................................................................................................................ 68 4.1 Study Population............................................................................................................................. 68 4.2 Fish Consumption and Exposure to Mercury .............................................................................. 69 4.2.1 Fish Species Included in the Multiple Regression Model ......................................................... 70 4.2.2 Fish Species Not Included in the Final Multiple Regression Model......................................... 76 4.2.3 Relevance of Blood-Mercury Concentrations ........................................................................... 78 4.3 The Effect of Angler Age, Sex, Ethnicity and Income on Mercury Exposure .......................... 80 4.4 Other Potential Sources of Exposure ............................................................................................ 83 4.5 Potential Policy Developments....................................................................................................... 84 4.6 Study Biases..................................................................................................................................... 86 4.6.1 Selection Bias ............................................................................................................................ 86 4.6.2 Misidentification of Fish Species .............................................................................................. 86 4.6.3 Portion Size Recall Bias ............................................................................................................ 87 4.6.4 Difficulties with Dietary Recall................................................................................................. 87 4.7 Study Strengths ............................................................................................................................... 88 4.7.1 Study Design ............................................................................................................................. 88 4.7.2 Data Collection .......................................................................................................................... 89 4.8 Study Limitations............................................................................................................................ 89 4.8.1 Study Design ............................................................................................................................. 90 4.8.2 Data Collection .......................................................................................................................... 90 4.8.3 Applicability of the Study Results............................................................................................. 91 4.9 Future Studies ................................................................................................................................. 92 4.9.1 Recruitment ............................................................................................................................... 92 4.9.2 Questionnaire............................................................................................................................. 92 4.9.3 Other Possibilities...................................................................................................................... 93  v
  5. Conclusion ............................................................................................................................... 95 References.................................................................................................................................... 96 Appendices................................................................................................................................. 106 Appendix A: Literature Review Strategy ......................................................................................... 106 Appendix B: Histograms and Quantile Plots of the Blood-Mercury Distribution ....................... 107 Appendix C: Complete Recreationally Caught Fish Consumption Report .................................. 110 Appendix D: Complete Commercially Bought Fish Consumption Report ................................... 111 Appendix E: Simple Linear Regression Results for Fish Species Reported by ≥ 5% of the Study Population............................................................................................................................................ 112 Appendix F: Initial Results of the Multiple Linear Regression Model.......................................... 113 Appendix G: Study Letter of Initial Contact ................................................................................... 114 Appendix H: BC Ministry of Environment Letter of Initial Contact ............................................ 116 Appendix I: Reminder Card .............................................................................................................. 117 Appendix J: Study Consent Form ..................................................................................................... 118 Appendix K: Study Instructions Letter ............................................................................................ 122 Appendix L: Questionnaire Guide .................................................................................................... 123 Appendix M: Fish Consumption Guide............................................................................................ 126 Appendix N: Questionnaire ............................................................................................................... 129 Appendix O: Questionnaire Script.................................................................................................... 147 Appendix P: Subject Response Letter - Blood-Mercury < 10 µg/L ............................................... 152 Appendix Q: Subject Response Letter - Blood-Mercury ≥ 10 µg/L............................................... 154  
  vi
  List of Tables
 Table 1. Tissue-mercury levels of common commercial fish species, ordered by descending mercury concentration, as determined by the CFIA between June 1, 2000 and March 31, 2010......................................................................................................................................... 9 Table 2. Health Canada’s fish consumption guidelines for fresh/frozen tuna, shark, marlin, swordfish, orange roughy and escolar (Health Canada, 2008). ............................................ 11 Table 3. HealthLink BC recommendations for fish consumption based on species, frequency of consumption and population demographic (HealthLink BC, 2011)..................................... 12 Table 4. Standardization of fish consumption frequencies to weekly consumption..................... 36 Table 5. Categorization of subject’s ethnicity based on their country of birth as well as their parents’ country of birth........................................................................................................ 37 Table 6. Blood-mercury concentrations in the study population.................................................. 42 Table 7. Sample characteristics: sex, annual personal income, current fishing license status, island region of residence and estimated ethnicity. .............................................................. 43 Table 8. Study population age and body weight stratified by sex (N = 195). .............................. 44 Table 9. Subject’s and subject’s parents’ countries of birth (N = 195). ....................................... 45 Table 10. Comparison of angler ages between the study population and all BC recreational anglers. BC angler ages were obtained from a consulting report conducted by GSGislason & Associates Ltd. et al. (2009). ............................................................................................ 46 Table 11. Blood-mercury concentrations stratified by sex, annual income and estimated ethnicity. ............................................................................................................................................... 47 Table 12. Total caught fish consumption stratified by sex, annual income and ethnicity............ 49 Table 13. Total bought fish consumption stratified by sex, annual income and ethnicity. .......... 50 Table 14. Total caught and bought fish consumption in grams of fish per week (N = 195). ....... 54 Table 15. Association between blood-mercury levels and total caught and total bought fish consumption.......................................................................................................................... 54 Table 16. Number of observations for each consumption frequency of the recreationally caught fish species reported by ≥ 5% of the study population (N = 195). ....................................... 55 Table 17. Recreational fish consumption in grams/week for caught species reported by ≥ 5% of the study population (N = 195) along with the percent of subjects who reported eating each species. Consumption is reported for the entire study population as well as for only those subjects who ate each species. .............................................................................................. 56 Table 18. Number of observations for each consumption frequency of the commercially bought fish species reported by ≥ 5% of the study population (N = 195). ....................................... 57 Table 19. Commercial fish consumption in grams/week for bought species reported by ≥ 5% of the study population (N = 195) along with the percent of subjects who reported eating each species. Consumption is reported for the entire study population as well as for only those subjects who ate each species. .............................................................................................. 59 Table 20. Associations between blood-mercury levels and species-specific fish consumption for the caught and bought fish species reported by ≥ 5% of the study population and with p ≤ 0.3. Species are listed in order of descending adjusted R2 values. ...................................... 60  vii
  Table 21. Blood-mercury results for the six subjects who reported working in any of the eight occupational areas of concern over the past year at the time of the questionnaire. Results are ranked by blood-mercury level, highest to lowest. ......................................................... 63 Table 22. Blood-mercury results for the nine subjects who reported past exposures to mercury. Results are ranked by blood-mercury level, highest to lowest. ............................................ 64 Table 23. Final multiple regression model for the dependent variable blood-mercury concentration (µg/L) and the independent variables caught rockfish, shellfish and cutthroat trout as well as bought other tuna, albacore tuna, snapper, and Estimated Ethnicity 1........ 66 Table 24. Number of anglers who reported consuming each recreationally caught fish species. ............................................................................................................................................. 110 Table 25. Number of anglers who reported consuming each commercially bought fish species. ............................................................................................................................................. 111 Table 26: Simple linear regression results for each recreationally caught and commercially consumed fish species reported by ≥ 5% of the study population. Species are listed in order of descending adjusted R2 values........................................................................................ 112 Table 27. Initial multiple regression model for the dependent variable blood-mercury concentration (µg/L) and the independent variables meeting the model inclusion criteria.113  viii
  List of Figures Figure 1. Subject recruitment strategy. ‘*’ denotes mailing facilitated by the BC Ministry of Environment.......................................................................................................................... 26 Figure 2. Study population recruitment. ....................................................................................... 41 Figure 3. Mean number of recreational fishing days per month between May 2009 and October 2010....................................................................................................................................... 51 Figure 4. Portion sizes for recreationally caught (grey) and commercially bought (black) fish (N = 195). ................................................................................................................................... 52 Figure 5. Frequency of total fish consumption of recreationally caught (grey) and commercially bought (black) species, regardless of species (N = 195)....................................................... 53 Figure 6. Occupations of the 195 study participants..................................................................... 62 Figure 7. Untransformed blood-mercury distribution................................................................. 107 Figure 8. Log-transformed blood-mercury distribution.............................................................. 108 Figure 9. Quantile plot of untransformed blood-mercury distribution. ...................................... 108 Figure 10. Quantile plot of log-transformed blood-mercury distribution................................... 109  ix
  Acknowledgements First and foremost, I would like to thank my thesis committee, Dr. Ray Copes, Dr. Hugh Davies and Dr. Kay Teschke, for their constant support and guidance. It was through their continuing patience, encouragement and advice that this project was possible. In their own way, each has helped me to better understand the principles of environmental health research and all committed countless hours to my academic development as well as to ensuring the success of this study. For all they have done for me, I am truly thankful. I would also like to thank the following for their contributions, all of which were integral for the success of this thesis: The BC Ministry of Health for funding this project. Without their assistance, this study would not have been possible. Diana Ralston and the laboratory staff of the British Columbia Children’s and Women’s Hospital for all of their hard work in analyzing blood samples. I would especially like to thank Dr. Benjamin Jung for his technical support and guidance as we developed the study protocol and progressed through the study. Chris Addison from the BC Ministry of Environment for his tireless assistance in organizing and facilitating the mailing of the hundreds of recruitment letters. The staff of each Vancouver Island LifeLabs® location, as well as Gail Thompson and Eileen Wood, for their assistance in collecting blood samples. Finally, I would like to thank my family. It is through their constant encouragement, love, and support that I am able to pursue my dreams and ambitions.  x
  1. Introduction Mercury is a heavy metal that enters the environment through various natural and anthropogenic means. When it enters aquatic environments, it can be transformed into methylmercury by microbial action. Biomagnification occurs and highest concentrations are typically found in predatory fish. Consumption of fish and shellfish is the most important source of exposure to this potent neurotoxin. Therefore, studying and understanding the multiple factors that affect exposure is essential for protecting the health of those who enjoy eating fish.  1.1 The Risks and Rewards of Fish Consumption 
 There are many health benefits associated with consuming fish. It is a substantial source of protein, essential fatty acids, vitamin D, and a number of micronutrients, all of which have been noted for an array of health benefits including proper fetal development and improved cardiovascular health (Mozaffarian & Rimm, 2006; Sidhu, 2003). Unfortunately, fish can also contain a number of contaminants. One of the most common is mercury. Recreational anglers are a subset of the general population who are likely to eat more fish for one main reason: they eat the fish that they catch along with the fish that they buy. As such, they are considered a population at risk of higher mercury exposure than the general population. Investigating fish consumption and mercury exposure in Vancouver Island anglers will provide valuable information on the species of fish they are consuming, their frequency of fish consumption, as well as how much fish they are eating, all of which are key determinants of exposure to mercury. Further, because this population is exposed to mercury from two different sources, i.e. recreational and commercial fish, evaluating fish consumption habits will help to determine the relative contribution of each to exposure. With this information, more relevant and effective fish consumption guidelines can be developed. Additionally, policy makers will have region-specific data that may help them to decide where best to allocate resources for protecting and promoting the health of this population through monitoring of mercury levels in fish and through other measures.  1
  1.2 Recreational Fishing on Vancouver Island 
 The extent of the sport fishing industry in British Columbia is substantial. In 2005, 270,000 British Columbians purchased a freshwater fishing license, while 245,000 purchased a tidal (saltwater) license1 (Fisheries and Oceans Canada, 2011; GSGislason & Associates Ltd. et al., 2009). Four hundred and eighty million dollars was spent on the recreational angling industry in the province that year with over 8 million fish caught, 2 million of which were kept. The popularity of sport fishing is also evident on Vancouver Island. In 2005, 32,000 angling licenses were sold with approximately $40 million dollars being spent on the industry and 154,000 angled fish being kept (GSGislason & Associates Ltd. et al., 2009). Given the abundance of freshwater and marine fish species, the size of the fishing industry and the thousands of caught fish that are not being released, it is clear that fish are an integral part of the diet on Vancouver Island and throughout British Columbia.  1.3 Mercury 
 Mercury (Hg) exists in two main states: elemental (Hg0) and reactive (Hg2+). When reactive Hg2+ binds with non-carbon compounds such as sulfur (HgS) or chloride (HgCl2), inorganic mercury is formed. Conversely, when compounds containing carbon bond with Hg2+, organic mercury is formed.  Under anaerobic conditions, bacteria can methylate Hg2+, creating  methylmercury (CH3Hg+). This process is made even more efficient with the presence of organic matter (Compeau & Bartha, 1985). Once in the environment, fish, shellfish, and other aquatic organisms absorb methylmercury where it binds strongly to muscle proteins (EPA, 2001a). Through biomagnification, the concentration of methylmercury increases up the food chain with larger predatory fish containing the greatest concentrations. Once humans consume these fish, methylmercury is efficiently absorbed by the gastrointestinal system and deposited in the kidneys and central nervous system (Brodkin et al., 2007).  























































 1 The BC government sells freshwater licenses while the Canadian government sells tidal licenses. Many anglers purchase both. 2
  1.3.1 Environmental Sources of Mercury 
 Mercury enters the environment both naturally and through anthropogenic means. While the human contributions tend to be publicized and are seemingly worse, they are generally smaller when compared to the natural sources of mercury (IPCS, 1989). One reason for this is that mercury commonly exists in rock. In British Columbia, minable deposits are found primarily in limestone and sandstone (Nagpal, 1989). Through weathering processes, mercury is introduced into bodies of water where it enters the food chain. However, mercury can also enter the environment through volcanic activity and forest fires where it is emitted into the atmosphere and later deposited to the ground or water (ATSDR, 1999; Sigler et al., 2003). Flooding and/or the creation of reservoirs are another method by which the heavy metal naturally enters the environment as any sequestered mercury in the soil, rock or vegetation can be released once impounded (Mailman et al., 2006; Bodaly et al., 2007). The other manner by which mercury enters the environment is through anthropogenic activities. Many chlor-alkali plants use mercury to produce caustic sodas and chlorine, and those that do release waste mercury into the air, water or soil. In some cases, the caustic soda can become contaminated with mercury. Caustic soda is used in pulp and paper mills, a major industry in BC, and its use may release mercury into the environment (EPA, 1997; Nagpal, 1989). The mining industry is another source of environmental mercury, whether the target of mining is mercury or not. Mercury can be released through drilling processes or as emissions from smelting. For example, elevated mercury levels in Pinchi Lake, BC were a result of a mercury mine that operated in the 1940s (Weech et al., 2004) while the Island Copper Mine on Vancouver Island was a notable source of mercury emissions between 1970 and 1995 (Nagpal, 1989; University of Victoria, No Date). One of the greatest sources of environmental mercury is through the burning of coal. For example, in the United States, “over 50 percent of all domestic human-caused mercury emissions” (EPA, 2010, Sources of mercury, para. 2) were as a result of burning coal.  Other sources of environmental mercury include waste incinerators, battery  manufacturing, and industrial spills (EPA, 1997). It should be noted that there are no active anthropogenic sources of mercury discharges or emissions on Vancouver Island. As such, the primary source of mercury in this region comes from natural and/or past industrial sources. This is more challenging from a policy standpoint since localized conditions, e.g. lake-to-lake 3
  variability in mercury content (Rieberger, 1992), make a single public health message inappropriate.  1.3.2 Methylmercury in Fish and in Humans 
 Mercury exists in various forms throughout the environment and continuously cycles between elemental, inorganic and organic states. Because of this, the mercury that is absorbed by fish, and consequently humans, exists in both the inorganic and organic forms. However, the majority of mercury found in fish tissues is methylmercury (Forsyth et al., 2004; Yamashita et al., 2005; Jewett et al., 2003). The ratio of methylmercury to total mercury in fish tissue differs between species. For example, methylmercury comprised 59% of the total mercury found in swordfish tissue samples but accounted for 71% of the total mercury in fresh/frozen tuna samples (Forsyth et al., 2004). Even greater ratios have been reported in other studies as Jewett et al. (2003) found that methylmercury made up 94% of the total mercury in Alaskan northern pike tissue samples and 95% of the total mercury in Alaskan arctic grayling tissue samples. While the amount of mercury found in fish tissue may differ between species, the greater concern for humans is that the “[o]ral absorption of organic mercury is nearly complete” (Brodkin et al., 2007, p. 61). Humans are also exposed to inorganic mercury through eating fish, although absorption of this form of mercury via the oral pathway is much less efficient (Brodkin et al., 2007). This could present a challenge when assessing exposure because methylmercury is the compound of concern yet many of the common tests for mercury determine total mercury content, i.e. inorganic and organic forms combined. However, as determined by Phelps et al. (1980) and AlMajed and Preston (2000), the ratio of inorganic to organic mercury in a total-mercury blood sample is approximately 5:95, i.e. 95% of the mercury in a total-mercury blood sample tends to be in the organic form (this ratio is 20:80 in hair). For this reason, it is generally assumed that the amount of total mercury found in a given blood sample is an accurate reflection of the amount of methylmercury present. As such, unless otherwise specified as another form of mercury, the term “mercury” will refer to methylmercury.  4
  1.4 Health Effects of Methylmercury Exposure 
 Methylmercury has a half-life of 39 - 70 days (mean of 50) in the human body and is capable of crossing the blood-brain barrier as well as the placenta (IPCS, 1990; Health Canada 2007a). Because of its ability to pass these barriers and deposit in the central nervous system, the neurotoxic properties of methylmercury are of greatest concern. The health effects associated with methylmercury exposure vary depending on the length of exposure, the dose, and the age of the individual. Much of what is known of high-dose exposure resulted from the two catastrophic events in Japan and Iraq. In the 1950s, residents living in Minamata, Japan were exposed to high concentrations of methylmercury through seafood consumption. This was a result of the Chisso chemicals plant that spewed waste mercury directly into Minamata Bay for over 25 years. Seafood in the bay was observed to contain methylmercury concentrations up to 35.7 µg/g (ppm) (Harada, 1995). In adults, paresthesia, malaise, deafness, ataxia, blurred vision and dysarthria were many of the common health effects observed with coma and death also occurring (Harada, 1995). Because of the ability of methylmercury to cross the placenta, many infants of exposed mothers were born with severe cerebral palsy or varying degrees of the aforementioned neurological health effects (Harada, 1995). In Iraq, these health effects were mirrored in the early 1970s after a fungicide containing methylmercury had been applied to seed grain, but the seed grain was used for making flour and bread. This resulted in over 400 deaths (IPCS, 1990). While the health effects associated with high-dose exposures are severe, the occurrence of such events is rare in the general population. Chronic, low-dose exposures to methylmercury are much more common and are associated with a variety of health effects as well. Again, the implications of exposure vary depending on the stage of development of those exposed. In adults, neurological health effects can include visual disturbances and disruptions in motor control, i.e. hand-eye coordination, dexterity, fine motor function, etc. (Yokoo, 2003). Recent studies also suggest that mercury is associated with cardiovascular health effects, such as myocardial infarction, hypertension and lowered contractile force (Guallar et al., 2002; Mozaffarian, 2009), as well as adverse effects on the immune system, such as increased inflammatory responses (Gardner et al., 2010).  5
  The consequences of methylmercury exposure were first realized following the events in Japan and Iraq. However, these were a result of dietary intakes much higher than are typical in the Canadian population. Perhaps the two best studies examining mercury exposure resulting from fish consumption were from the Faroe Islands and the Seychelles.  In the Faroe Islands,  Grandjean et al. (1992) obtained 53 blood samples from a pilot population on Lorvik (one of the 18 islands that comprise the Faroe Islands), as well as 997 blood samples as part of the main study from the rest of the islands. This population was of specific interest because the Faroese diet contains whale meat and blubber, which have mean mercury concentrations of 3 µg/g. Because the purpose of the study was to determine methylmercury levels among children, only women and their babies were sampled. In the pilot study, venous blood samples were taken from childbearing-aged women while in the birth cohort umbilical cord blood was sampled. Results from the pilot study showed a median blood-mercury concentration of 60 nmol/L (12 µg/L) for the 53 samples. For the birth cohort, a dose-response relationship was observed where an increased frequency of whale meat consumption resulted in higher umbilical cord blood-mercury levels. The median mercury level for the 997 samples was 121 nmol/L (24.3 µg/L), although Grandjean et al. (1992) attributed this difference, as compared to the pilot study, to the fact that venous blood typically contains 20 - 65% less mercury. To put these values into perspective, the most recent results of the Canadian Health Measures Survey (CHMS) show that 95% of Canadians have ≤ 23.4 nmol/L (≤ 4.7 µg/L) of mercury in their blood (Health Canada, 2010). While the primary purpose of the study was to determine the amount of mercury that fetuses were exposed to, it was clear that frequently consuming seafood products high in mercury results in greater exposure. Around the same time the study in the Faroe Islands was being conducted, another study investigating mercury exposures among a population that frequently consumes fish containing elevated concentrations of mercury was being conducted in the Seychelles. While the eventual goal of this study was to determine health outcomes of children as a result of prenatal exposure, Matthews (1983) conducted a pilot study to assess the state of exposure throughout the population.  The Seychelles was an area of interest because the population’s estimated  consumption of fish was between 80 - 100 kg per person per year, which was considered to be very high. In addition, the most popular species consumed were higher in mercury. Matthews  6
  (1983) found that bonito made up 5-10% of the market supply with an estimated 57.5% of this catch containing > 0.5 µg/g of mercury and 4% containing > 1.0 µg/g. Caranx, a species that makes up an estimated 25% of the market supply showed similar trends in mercury content. With the risk of mercury exposure, Matthews (1983) analyzed hair samples from 40 Seychellois men and 36 mother-newborn pairs to determine whether mercury levels found in fish were reflected in humans. Of the 40 males tested, the average hair-mercury concentration was 26.3 ± 14.5 µg/g with a range of 5.50 - 68.2 µg/g (note: Health Canada hair-mercury guideline is 6 µg/g). Of the 36 women, the average hair-mercury level was 12.0 ± 6.60 µg/g and was 15.3 ± 11.5 µg/g in the newborns. While this was the pilot study for the larger Seychelles Child Development Study, it provided ample evidence of mercury exposure from fish consumption. While the health effects of chronic, low-dose exposure have been associated with detrimental health effects in adults, the most susceptible populations include developing fetuses and children (Grandjean et al., 1992; Harada, 1995). Neurological health effects in infants include decreases and deficits in motor control, attention, learning and memory (Grandjean et al., 2003; Innis et al, 2006). These health effects are hypothesized to result from the ability of methylmercury to disrupt brain development, specifically by “interfer[ing] with microtubule formation, cell division, and neural protein synthesis” (IPCS, 1990, 10.2.2 Prenatal exposure, para. 3). It is therefore prudent to restrict exposure among pregnant women and women of childbearing age. While these neurological health effects are concerning for the developing fetus, clinical manifestations of neurological symptoms in adults typically occurs at higher levels of exposure. In adults, the effects on the cardiovascular system are the critical effect (Mozaffarian, 2009).  1.5 Mercury Concentrations in Canadian Fish 
 Mercury levels vary greatly between fish species, usually in a predictable and understandable manner. For most individuals, exposure to mercury in the diet is largely a function of the mercury concentration in the fish consumed, the frequency of fish consumption and portion size. Fish species is one of the most important determinants of exposure when considering mercury. The Canadian Food Inspection Agency (CFIA) enforces a tolerance in commercially sold fish of  7
  0.5 µg/g or 1.0 µg/g depending on the fish species (Health Canada, 2007a). While the CFIA monitors commercial fish species, the monitoring of sports caught species for mercury, as well as the development of fish consumption guidelines for sport-fish, is the responsibility of provincial governments (Health Canada, 2007b). In British Columbia, many of the fish species that are caught recreationally are also available commercially. If commercial and sport-fish are from the same stocks, monitoring results may be generalized. Table 1 illustrates mercury levels in select Canadian fish species as determined by the CFIA between June 1, 2000 and March 31, 2010. While many of the fish tissue samples were acquired as part of retail monitoring, others were taken for different reasons, including other regulatory work, foreign compliance testing and other requested inspections.  Please note that the CFIA provided the most recent tissue-mercury  sampling results (number of samples, mean, maximum value and minimum value) for over 200 fish species via email communication (personal communication with John Hoeve, November 16, 2010). These are the most up to date results and have yet to be published by the CFIA. Any reference to CFIA tissue-mercury levels in this report was obtained from this database.  8
  Table 1. Tissue-mercury levels of common commercial fish species, ordered by descending mercury concentration, as determined by the CFIA between June 1, 2000 and March 31, 2010. Fish Species  Number of Samples  Mean Tissue-Hg (µg/g)  Swordfish  47  1.041*  Marlin  114  0.785*  Fresh/Frozen Ahi Tuna  42  0.566*  Canned Albacore Tuna  395  0.395  Sablefish  380  0.363  5  0.316  Fresh/Frozen Albacore Tuna  131  0.278*  Pacific Halibut  97  0.257  Rockfish  51  0.230  Lingcod  6  0.192  Canned Skipjack Tuna  137  0.070  Rainbow Trout  50  0.039  Sockeye Salmon  27  0.034  Atlantic Salmon * CFIA regulatory limit of 1.0 µg/g  222  0.027  Smallmouth Bass  1.6 The Effect of Fish Consumption Frequency and Fish Portion Size on Mercury Exposure 
 Most of the tissue-mercury concentrations presented in Table 1 are below the CFIA regulatory limits. However, simply eating fish species that meet federal standards does not in itself limit exposure to mercury. Dabeka et al. (2004) surveyed common retail fish species and found tissue-mercury levels similar to those recorded by the CFIA. The authors took this information and applied it to reasonable estimates of portion size and consumption frequency to determine mercury exposure and then made comparisons to Health Canada’s provisional tolerable daily intake of 0.2 µg/kg/day for children and women of childbearing age. Dabeka et al. (2004) determined that a 57.2-kg woman who consumed a 225 g portion of fish once per month that contained 1.5 µg/g of mercury would have an approximate daily mercury intake2 of 0.22 























































 2 Including a dietary mercury intake of 0.0194 µg/kg/day from other foods. 9
  µg/kg/day, which would exceed the provisional tolerable daily intake. While fish containing this level of mercury, such as swordfish and shark, are consumed infrequently by the general population (Health Canada, 2007a), species that contain moderate amounts of mercury (0.1 - 0.4 µg/g) are eaten more often (Lincoln et al., 2011). In addition, anglers likely consume multiple fish species and may eat larger portion sizes. All of these factors make exceeding the provisional tolerable daily intake a possibility. As demonstrated by Dabeka et al. (2004), mercury exposure resulting from fish consumption is a multifaceted issue where the frequency of consumption, as well as portion size, are just as important in determining exposure as the species of fish eaten.  1.7 Public Fish Consumption Guidelines 
 Public fish consumption guidelines are promulgated by a variety of organizations including Health Canada and the BC Ministry of Health.  1.7.1 Canadian Fish Consumption Guidelines 
 Because of the health benefits associated with consuming fish, Health Canada recommends that all Canadians eat at least two 75-g sized portions of fish per week (Health Canada, 2008). In terms of species, recommendations focus on consuming fish that contain greater amounts of essential fatty acids, such as eicosapentoic and docosahexaenoic acids, and contain lower amounts of mercury. Some of these species include salmon, rainbow trout, char, herring and various types of shellfish, i.e. blue crab, shrimp, mussel, clams and oysters (Health Canada, 2008). In recognition of the mercury content of large, predatory species of fish, Health Canada has developed a guide for the consumption of fresh/frozen tuna, shark, marlin, swordfish, orange roughy and escolar, i.e. those to which the 1.0 µg/g tolerance applies. These guidelines also take into account the susceptibility of children and developing fetuses as outlined in Table 2.  10
  Table 2. Health Canada’s fish consumption guidelines for fresh/frozen tuna, shark, marlin, swordfish, orange roughy and escolar (Health Canada, 2008). Canadian Demographic  Consumption Limit  General Population  150 g per week  Women of Childbearing Age and Those Who Are Breastfeeding  150 g per month  Children 5-11 Years Old  125 g per month  Children 1-4 Years Old  75 g per month  Health Canada has also created consumption guidelines for canned albacore tuna, i.e. canned ‘white’ tuna. These guidelines target susceptible populations only and suggest limits of 300 g/week for women of childbearing age, 150 g/week for children between the ages of five and eleven years and 75 g/week for children between the ages of one and four years. Health Canada does not place guidelines on canned ‘light’ tuna since skipjack and yellowfin tunas typically contain lower amounts of mercury (Health Canada, 2008).  1.7.2 British Columbia Fish Consumption Guidelines 
 Provincial health organizations also have recommendations for fish consumption. HealthLink BC (2011) has published a nutrition series for commonly consumed fish species. It stratifies fish into three consumption-frequency categories based on the mercury content of the fish species and the population demographic (Table 3).  Compared to the federal guidelines, the BC  recommendations are more extensive and with the exception of a few missing species, i.e. lingcod, crab and certain types of trout, cover many species that are both commercially bought and recreationally caught.  11
  Table 3. HealthLink BC recommendations for fish consumption based on species, frequency of consumption and population demographic (HealthLink BC, 2011). Fish Species Age Salmona 6-24 months Shrimp 2-12 years Prawn Eat Freely Rainbow Trout Girls & Childbearing-Aged Atlantic Mackerel Women Sole/Dover Sole Men (>12 years) and Women Albacore Tunab Older Than Childbearing Age c Canned Tuna 6-24 months Imported Albacore Tuna 2-12 years Atlantic Cod Girls & Childbearing-Aged Eat in Bass or White Bass Women Moderation Pacific Halibut Lake Trout Men (>12 years) and Women Sablefish Older Than Childbearing Age Rockfish Bigeye (Ahi) Tuna 6-24 months Shark 2-12 years Marlin Girls & Childbearing-Aged Swordfish Women Limit Sea Bass Barracuda Men (>12 years) and Women Escolar Older Than Childbearing Age Arctic Char Grayling * 1 serving = 75 g a All types: fresh, frozen, wild, farmed or canned b Fresh, frozen or canned from Canada or BC ONLY c All types except those from Canada or BC  Serving Limit* No Limit No Limit No Limit No Limit 2/month 3/month 2-4/week 4-6/week Do Not Eat 1/month 2/month  4/month  1.8 Evidence of Methylmercury Exposure from the Consumption of Fish 
 Studies into mercury exposures as a result of consuming fish span the globe. An in-depth literature review was conducted to evaluate the state of research in this field3. The vast majority of the reviewed studies examined populations that were deemed to be at risk of exposure either because they ate fish species that contained higher amounts of mercury or because they consumed fish frequently, such as recreational anglers. 























































 3 Literature review search criteria can be found in Appendix A. 12
  While the studies in the Faroe Islands and Seychelles may be considered the most comprehensive, a study conducted by Wheatley and Paradis (1995) examined methylmercury exposures among the aboriginal populations of Canada. From 1970 to 1992, 71,842 blood and hair samples were collected from aboriginal communities throughout Canada to assess exposure to mercury. Reasons for examining this population were two fold. First, a traditional aboriginal diet may include frequent fish consumption, as well as the consumption of sea mammals that may contain high amounts of mercury, such as whale and seal. Second, some of the targeted communities consumed fish that were downstream of various industrial processes, such as chloralkali plants. In some cases, tissue-mercury levels in fish from these rivers were as high as 24 µg/g. Of the 38,751 individuals that were tested, 21.4% had a blood-mercury level between 20 µg/L and 99 µg/L, 1.4% had levels between 100 µg/L and 199 µg/L and 0.2% had levels > 200 µg/L. These concentrations were much higher than the general Canadian population as outlined by the Canadian Health Measures Survey where 95% of the population had a blood-mercury level ≤ 4.7 µg/L (Health Canada, 2010). In general, elevated blood-mercury levels among Inuit populations were attributed to the consumption of whale and seal meat while increased exposure in southern aboriginal communities was a result of frequent fish consumption, particularly from contaminated waterways. The highest observed blood-mercury level was 660 µg/L in a fishing guide from a community downstream of a chlor-alkali plant in Dryden, Ontario (Wheatley and Paradis, 1995). This study, along with those conducted in the Seychelles and Faroe Islands, demonstrated that frequently consuming seafood products that contain high levels of mercury results in elevated exposure. However, what about the effect of consuming fish that contain only moderate levels of mercury? This has been the focus of more recent studies, most of which focus on a population who are likely to consume more fish than the general population: recreational anglers. In one study examining mercury exposures among a Swedish angling community, Johnsson et al. (2004) administered a dietary questionnaire focusing on fish consumption and obtained hair samples from 143 anglers. Pike and perch were the two most common species of fish reported, both of which had tissue-mercury concentrations between 0.6 µg/g and 0.7 µg/g. The authors observed a distinct increase in hair-mercury levels as the frequency of fish consumption  13
  increased, ranging from 0.5 µg/g of hair-mercury in those who consumed fish < once per month to 2.1 µg/g in those who consumed fish ≥ once per month to 2.7 µg/g in those who ate fish ≥ once per week and up to 3.9 µg/g in those who ate fish ≥ twice per week. The conversion factor between hair and blood mercury is 1.0 µg/g of mercury in hair to 4.0 µg/L of mercury in blood (EPA, 2001b). Therefore, a hair-mercury concentration of 3.9 µg/g would be equivalent to a blood-mercury level of 15.6 µg/L. In a study with a similar design and results, Kosatsky et al. (2000) surveyed the dietary habits of 132 Quebecois recreational anglers as well as collected blood and hair samples that were analyzed for mercury. Pike, perch and walleye, caught from the St. Lawrence River, were the three species of fish that were the strongest predictors of mercury exposure (α = 0.1). With regards to fish consumption frequency, blood-mercury levels were higher in the 60 anglers who consumed ≥ one fishmeal per week compared to the 71 anglers who ate < one fishmeal per week (3.03 ± 2.43 µg/L vs. 1.44 ± 2.23 µg/L respectively). This pattern was also observed among the hair samples (0.82 ± 2.54 µg/g vs. 0.38 ± 2.28 µg/g respectively). These results reflected those of an earlier study conducted by Mahaffey and Mergler (1998) who examined blood-mercury levels of 288 Quebec residents who consumed fish from two inland lakes that flow into the St. Lawrence River. The mean blood-mercury level for the anglers who never consumed fish from these lakes was 0.56 µg/L and 0.91 µg/L for those that did. While this study did not specify the species of fish consumed or the frequency of consumption, Mahaffey and Mergler (1998) concluded that because fish consumption from other sources was likely to be minimal, the bloodmercury levels observed were a result of the fish in the two lakes. While many of these studies focus on mercury exposure from the consumption of recreationally caught fish species, there is also a concern of additional exposure from the consumption of commercially bought fish species. Kosatsky at al. (2000) did take this into account but found that consumption of commercial fish related negatively to blood-mercury, which they attributed to the over-reporting of recreational fish consumption.  Interestingly, in bivariate analysis,  commercial fish consumption was the only variable that demonstrated a negative relationship between consumption and geometric mean blood-mercury concentration (1.39 µg/L [1.08 - 1.80] in those who consumed ≥ one meal/week vs. 2.30 µg/L [1.90 - 2.77] in those who ate < one  14
  meal/week). Cole et al. (2004) examined blood-mercury levels among Ontario recreational anglers with a focus on both sport-fish and commercial fish consumption. Two populations were examined in this study.  The first included anglers who fished in areas with active fish  consumption advisories. Examining sport-fish consumption only, the geometric mean for bloodmercury was 1.5 ± 2.0 µg/L for the 56 anglers who consumed no fish, 2.1 ± 1.9 µg/L for the 137 anglers who ate between 1 and 52 meals/year and 2.7 ± 2.4 µg/L for the 39 who ate > 52 meals per year. In terms of commercial consumption, the geometric mean blood-mercury for the 117 subjects who consumed ≤ 36 meals/year was 1.9 ± 2.0 µg/L and was 2.1 ± 2.0 µg/L for those who ate > 36 meals/year.  While there was a positive dose-response relationship in this  population, none of the results were significant (α = 0.05). The second group included subjects who frequently consumed fish from Great Lakes locations deemed to be areas of concern because of elevated pollution levels. Dietary questionnaires were administered along with the collection of blood samples. Similar to the first population, blood-mercury levels increased with the frequency of consumption, however the differences between exposure groups in the second population were significant (α = 0.05). In terms of sport-fish consumption, the geometric mean blood-mercury concentration was 2.7 ± 2.4 µg/L among the 50 anglers who ate ≤ 186 sport-fish meals per year and 6.3 ± 2.2 µg/L among the 35 that consumed > 186 meals per year. Examining commercial consumption, the geometric mean blood-mercury was 2.9 ± 2.5 µg/L for the 43 anglers who ate 2 - 52 commercial meals per year and 5.3 ± 2.4 µg/L for the 43 who consumed between 53 and 116 meals/year.  While Cole et al. (2004) acknowledged the  contribution of commercial fish to blood-mercury levels, there was no definite conclusion as to whether it was the commercial or recreational species of fish that contributed the most to exposure. Due to the pollution present in the Hudson River, Gobeille et al. (2006) conducted a crosssectional study involving 191 recreational anglers from New York and New Jersey. Similar to the study conducted by Kosatsky et al. (2000), subjects were recruited as they fished the river and were administered a questionnaire focusing on their fish consumption habits. Gobeille et al. (2006) then collected blood samples to be analyzed for mercury. The mean blood-mercury level was found to be 2.4 ± 1.2 µg/L among anglers who ate fish from the river and 1.3 ± 1.1 µg/L in those who did not. While this study primarily focused on recreational fish species, the study did 15
  attempt to capture exposure information from commercial fish as a whole, i.e. without identifying specific fish species. Unlike the dose-response relationship observed with sport-fish consumption, there was no relationship seen when examining commercial fish consumption. Knobeloch et al. (2007) conducted an extensive study that examined mercury exposure among recreational anglers in Wisconsin. Through a variety of means, they were able to recruit over 2000 subjects. Using a combination of dietary questionnaires and hair samples, they concluded that as reported fish consumption increased, so did measured mercury levels. The mean hairmercury level was 0.714 µg/g and ranged from 0.012 µg/g to 15.2 µg/g. Unlike Gobeille et al. (2006) who did not differentiate between commercial fish species, Knobeloch et al. (2007) separated commercial fish into three categories: ‘canned tuna’, ‘restaurant’ and ‘purchased’. Compared to the anglers that consumed only recreationally caught fish, those who only consumed these commercial fish types had a lower mean hair-mercury concentration (0.89 µg/g compared to 0.51 µg/g). However, compared to those who ate no fish at all, those who ate commercial fish had a greater mean hair-mercury level (0.51 µg/g compared to 0.09 µg/g). While this study attempted to account for mercury exposure from commercial fish consumption, it did not investigate exposure on species-specific basis. In attempting to evaluate whether commercial or recreational fish species contributes the most to angler exposure, Lincoln et al. (2011) conducted an exposure assessment among Louisiana recreational anglers.  Similar to other studies, a questionnaire was used to evaluate fish  consumption habits in combination with a hair sample analyzed for mercury. From the 402 participants, the mean hair-mercury level was 1.1 ± 1.1 µg/g with a range of 0.02 - 10.7 µg/g. By combining dietary recall information with an estimated tissue-mercury concentration from each reported fish species, the authors found that approximately two-thirds of all fish meals were from recreational sources and that recreational fish species were responsible for 74% of mercury exposure. The remaining contribution came from commercial consumption with canned tuna accounting for the majority of that exposure. Unfortunately, while they estimated mercury intake from each species, they did not compare them with hair-mercury levels. Instead, they aggregated the mercury estimates from each species into one variable and compared it to their biomarker. As such, they did not include each fish species into their multivariable regression  16
  models. Lincoln et al. (2011) concluded that exposure to mercury was greatest from the frequent consumption of fish species that contained low to moderate amounts of mercury as opposed to those that contained higher amounts of mercury. While the authors did not specifically define the terms ‘low’, ‘moderate’ and ‘high’, they considered speckled trout (0.11 µg/g) and crab (0.18 µg/g) to contain low amounts of mercury, canned tuna (0.35 µg/g) and fresh tuna (0.38 µg/g) to contain moderate amounts of mercury and swordfish (0.98 µg/g) to contain high amounts of mercury (Lincoln et al., 2011). From a policy perspective, Lincoln et al. (2011) believe that current U.S. consumption advice, which is based on the consumption of select commercial species that contain higher amounts of mercury, fails to protect populations who frequently consume region-specific fish species containing low to moderate amounts of mercury. While these types of guidelines are meant to protect the population as a whole, they fail to address those individual populations that consume local fish species not covered by federal guidelines. The consensus within the literature is that the frequency of fish consumption, as well as the mercury concentration in the fish consumed, are important determinants of exposure. While increases in blood and hair mercury levels were observed across a number of studies, it should be noted that these elevations rarely approached the Canadian health guidelines for blood and hair mercury levels, where intervention strategies4 should begin at a blood-mercury level of 8 µg/L (hair-mercury of 2 µg/g) for women < 50 years old and men ≤ 18 years old and at 20 µg/L (hairmercury of 6 µg/g) for women ≥ 50 years old and men > 18 years old (Legrand et al., 2010). However, many of these studies did contain one or two individuals who surpassed these guidelines. Further, with the exception of a few studies, there is little research into how the combined consumption of recreational and commercial fish influences exposure to mercury, especially on a species-specific basis. With the increased potential for exposure from both of these sources, additional research is needed.  1.9 Demographics and Patterns of Mercury Exposure 
 Within the literature, certain demographic characteristics are common with respect to mercury exposure resulting from fish consumption. Angler gender is one such factor with men having 























































 4 Dietary advice and a repeat mercury test in six months (Legrand et al., 2010). 17
  higher mercury levels than women (Johnsson et al., 2004; Mahaffey & Mergler, 1998; Cole et al., 2004; Knobeloch et al., 2007). Reasons for this include greater amounts of fish consumption among men (Johnsson et al., 2004; Mahaffey & Mergler, 1998; Knobeloch et al., 2007) as well as women transferring mercury to their infants either in utero or through breast feeding (Cole et al., 2004; ATSDR, 1999). Income is another factor correlated with increased exposure. Hightower and Moore (2003) found that those earning mid to high incomes tended to consume more expensive species that contained higher amounts of mercury. They found that 89% of their respondents exceeded the reference dose and that blood-mercury levels correlated the most with swordfish consumption. Interestingly, Cole et al. (2004) observed a U-shaped correlation between mercury levels and income, which was attributed to lower income participants 1) eating more fish and 2) consuming fish from lakes closer to home where there was greater anthropogenic contamination. This was in contrast to high-income participants who travelled to locations where lakes were contaminated from natural sources. While intriguing, this U-shape may not be a universal observation; their study focused on a very specific geographic area. Angler age is a third variable that may affect exposure to mercury, however the results from exposure studies are mixed. Mahaffey and Mergler (1998) reported that individuals 45 and older had greater blood-mercury levels as a result of increased fish consumption compared to those who were between 15 and 44 years of age. While Kosatsky et al. (2000) found no association between blood-mercury level and age in bivariate analysis, they did determine age was a predictor in multivariable analysis with blood-mercury increasing with age. Further, in a large cohort study conducted by Rhainds et al. (1999) that examined mercury levels in cord blood of Quebec newborns, blood-mercury concentrations significantly increased with age among the 1126 mothers who participated. However, in contrast to this, Lincoln et al. (2011) found that among 402 Louisiana recreational anglers, there was a decreasing trend in hair-mercury concentration with age, albeit an insignificant one. In general, there appears to be a positive relationship between age and mercury exposure with an increase in fish consumption being the cause.  18
  Finally, ethnicity is another demographic factor seen to effect exposure. Specifically, East Asian fish consumers tend to eat more fish and consequently have greater hair and/or blood-mercury levels (Knobeloch et al., 2005; Cole et al., 2004). One such study found that East Asian consumers ate twice the number of fish meals/year compared to Euro-Canadian consumers (Cole et al., 2004), which resulted in blood-mercury levels almost four times as high in some instances. This trend was also observed by McKelvey et al. (2007) who attributed elevated blood-mercury levels in Asians to fish consumption. Compared to Whites (5.5%), Blacks (5.5%) and Hispanics (1.3%), McKelvey et al. (2007) found that 19% of the Asians surveyed had consumed fish at least 20 times in 30 days. As illustrated by the study conducted by Wheatley and Paradis (1995), aboriginals who consume a traditional diet type are at greater risk of exposure through the consumption of higher mercury-containing species such as whale. While these differences are essentially a result of diet type, there is also the possibility of genetic polymorphisms that may influence mercury body burden. For example, in Japanese, Vietnamese, Chinese and First Nations populations, there is a common polymorphism in the enzymes aldehyde dehydrogenase 2 and glutathione S-transferase, both of which are responsible for the export of mercury from human cells, that may reduce the excretion of mercury (Canuel et al., 2006).  1.10 Summary and Gaps in the Literature 
 Overall, there are a number of studies outlining mercury concentrations in fish, as well as exposures to anglers who consume their catch. In general, mercury levels seem to vary among fish species with little debate that large, predatory fish, such as swordfish, shark, orange roughy, marlin and tuna contain the highest amounts of mercury. With the exception of tuna, these species are typically only available commercially. However, there are a number of other fish species, both commercially available and frequently caught recreationally, that contain moderate amounts of mercury such as halibut, lingcod, and rockfish. Further, there are certain species that also contain moderate amounts of mercury that are typically only recreationally caught including northern pike, walleye, lake trout, smallmouth bass, and largemouth bass. Species that are generally low in mercury and are available both commercially and recreationally include salmon, shellfish and rainbow trout. While earlier studies, such as those conducted in the Faroe Islands and Seychelles, demonstrated that the consumption of fish species containing high levels of  19
  mercury resulted in increased mercury body burden, recent studies focusing on anglers demonstrated that even frequent consumption of species containing only moderate amounts of mercury can increase exposure. The concentration of mercury in the fish consumed, the consumption frequency, and the amount of fish eaten are all important predictors of exposure. There are also differences by gender, ethnicity and income as males, people of East Asian and aboriginal descent and those with higher incomes, tend to have greater mercury levels. However, the three main predictors of exposure typically explain these demographic differences. In terms of gaps in the literature, there seems to be little information regarding the relative contributions of commercially bought and recreationally caught fish. Earlier studies, such as those by Grandjean (1992) and Matthews (1983), typically looked at fish consumption as a whole, particularly since the populations they examined all consumed high amounts of fish regardless of whether it is caught or bought. Recent studies, such as those conducted by Mahaffey and Mergler (1998), Kosatsky et al. (2000), Cole et al. (2004) and Gobeille et al. (2006), primarily focused on recreational anglers and sport-fish consumption with minimal focus on commercial fish consumption. Within these studies, the interest remained on freshwater species, which is concerning for Vancouver Island anglers since many fish species containing moderate amounts of mercury, such as halibut, are saltwater species.  Only recently, as  evidenced by the study conducted in Louisiana by Lincoln et al. (2011), has there been a direct focus on both commercial and recreational fish species from fresh and saltwater sources. Further, there are no studies focused in British Columbia, which is surprising given that recreational angling is a common activity in both fresh and saltwater. Vancouver Island is home to a large recreational fishing industry. Both fresh and saltwater species are consumed, some of which may contain moderate to high amounts of mercury. Unfortunately, there is no regionspecific information within the literature that evaluates the risk of mercury exposure to these anglers. There is also no information that attempts to characterize the risk of exposure from what they are catching as well as what they are buying, let alone on a species-specific basis.  20
  1.11 Study Rationale 
 Fish consumption habits, i.e. frequency of consumption, amount eaten and species eaten, have been correlated with increases in hair and blood mercury. Vancouver Island recreational anglers are more likely to consume sport-fish more often and in larger quantities than the general Canadian public. Many of the locally available species in BC, such as halibut, rockfish and lingcod, have been shown to contain moderate amounts of mercury. Given that many of these anglers are also likely to eat commercial fish, some of which may contain concentrations of mercury greater than CFIA tolerances, mercury levels in this population could be quite high. While the effect of fish consumption on mercury exposure is relatively well known, an in-depth assessment is required to determine whether exposure is greater from the fish that is recreationally caught or from the fish that is commercially bought and how these relate to the three main determinants of exposure, especially on a species-specific basis. This is particularly true on Vancouver Island where anglers eat a variety of commercial and recreational fish species from both marine and freshwater sources. Studying exposures among this population is also important because such an assessment has never before been conducted in a Canadian west coast population. Further, evaluating variations in exposure based on demographic factors such as sex, ethnicity and income, will help to better appraise exposure in this population and lead to targeted policy developments and fish consumption guidelines.  1.12 Study Objectives and Hypotheses 
 The objective of this study was to examine blood-mercury levels in Vancouver Island recreational anglers with a focus on determining whether commercially bought or recreationally caught fish consumption contributes the most to dietary intake of methylmercury. To achieve this objective, the following hypotheses were posed: 1. Among anglers who consume fish in similar quantities and frequencies, those who eat a higher ratio of commercially bought vs. recreationally caught fish, will have higher bloodmercury levels due to certain commercial species that contain greater amounts of mercury.  21
  2. Among anglers who consume fish in similar quantities and frequencies, those who eat a majority of species containing low amounts of mercury will have lower blood-mercury levels. 3. The greater the total fish consumption, the greater the blood-mercury will be, i.e. there will be a direct relationship between reported fish intake and blood-mercury, a biomarker of mercury exposure. 4. Anglers of East Asian descent will have greater blood-mercury levels due to a higher frequency of consumption. 5. Males will have a higher blood-mercury level due to greater amounts and higher frequencies of consumption. 6. Anglers of moderate income will have the lowest blood-mercury level as those of lower income will consume a greater amount of fish (mainly recreational) while those of higher income will consume species containing higher amounts of mercury (mainly commercial). To evaluate these hypotheses, the following research questions were posed: 1. Among Vancouver Island recreational anglers, how much of the fish they eat is caught vs. bought? 2. What fish species are Vancouver Island anglers catching and eating? 3. What fish species are Vancouver Island anglers buying and eating? 4. How often are the anglers eating both recreationally caught and commercially bought fish? 5. How does blood-mercury level vary in anglers with respect to varying consumption of commercially bought and recreationally caught fish? 6. What are the differences in blood-mercury levels when considering demographic factors such as angler age, sex, ethnicity and income?  22
  2. Methodology 
 This study was conducted on Vancouver Island, British Columbia. Vancouver Island has an area of 32,134 km2, a population of approximately 750,000 and is located off the southwest coast of mainland British Columbia. Both quantitative and qualitative assessments were conducted to evaluate mercury exposures among recreational anglers who reside on the island. Qualitatively, anglers answered a questionnaire that provided information on the species of fish they consumed, both caught and bought. Quantitatively, subjects provided a blood sample that was analyzed for mercury as well as information on the frequency and portion size of the fish they consumed. The University of British Columbia’s Clinical Research Ethics Board approved all study methods.  2.1 Study Population 
 The study population was recreational anglers living on Vancouver Island. This population was expected to have the greatest exposure to mercury from caught fish. Although it was expected that recreational anglers would also consume fish they purchased, there may be other groups who eat more purchased fish overall. Vancouver Island was chosen because the island has many blood collection locations, which increased the ease of obtaining blood samples, and is a welldefined and manageable geographic region where most recreationally angled fish are likely caught either on the island or just off the coast. It is also an area where sport fishing is well developed and economically significant from a tourism perspective. The target study sample size was 200, which was determined by considering the number of observations per variable required for a multiple regression model5. Subjects were recruited from the BC Ministry of Environment’s (BC MoE) freshwater fishing license list. This list is a database of all freshwater fishing licenses purchased in British Columbia. There are a number of licenses available, for resident, non-resident and non-resident alien anglers. These include: •  Annual license  •  Annual license for the disabled  • Annual license for those ≥ 65 years old 























































 5 Based on 10 observations per variable. With an estimated 20 variables being included in the multiple regression model, a sample size of 200 would be required. 23
  •  1-day license  •  8-day license  The inclusion criteria for the study population were as follows: •  Must have held an annual freshwater fishing license (including those for the disabled or ≥ 65 years old) at some point during the year preceding their study enrollment date6  •  Must be ≥ 19 years old  •  Must reside on Vancouver Island  With these criteria, approximately 27,000 anglers were eligible for the study.  2.2 Subject Recruitment 
 Between June and November 2010, four waves of subject recruitment were conducted to obtain the target study population of 200. Initial contact with all participants was made via mail. Vancouver Island addresses were selected at random from the BC MoE license list to obtain a geographically homogeneous sample.  Because access to this list was restricted for  confidentiality reasons, the BC MoE facilitated this mailing, which contained both the study and government’s letters of initial contact. The study’s initial contact letter outlined the purpose of the study, what participation would entail, the assurance of confidentiality and the contact information (telephone number and email address) of the study coordinator. The letter also described a $25 honorarium in the form of a gift card to a Vancouver Island sport-fishing store in appreciation for fully completing the study, i.e. completion of both the questionnaire and blood sample. This incentive was provided to stimulate enrollment. The primary purpose of the initial contact letter provided by BC MoE was to reassure each angler that their private information had been kept confidential, as protected by the Freedom of Information and Protection of Privacy Act. Three weeks following the initial mailing, the BC MoE mailed a reminder postcard to the same addresses. Copies of these documents can be found in Appendices G - I.  























































 6 Anglers are able to purchase their license from the BC government at any time. As such, some of their licenses had expired at the time of the study. However, subjects were included if they had held a valid license at some point during the year prior to their study enrollment date. 24
  Anglers who were interested contacted the study directly to enroll.  From this point, all  communication with the subjects occurred without the involvement of the BC MoE. Upon enrollment, demographic information, i.e. address, sex, contact information and date of birth, was collected and a date on which the telephone questionnaire could be administered was decided upon. A research package, which included the documents required to complete the study, was then mailed to the subject (see section 2.3). Figure 1 outlines the recruitment strategy.  25
  Target Population (N = 200)  Recruitment Wave 1  Recruitment Wave 2  Recruitment Wave 3  Recruitment Wave 4  Letters of Initial Contact Mailed to 250 V.I. Addresses*  Letters of Initial Contact Mailed to 500 V.I. Addresses*  Letters of Initial Contact Mailed to 1500 V.I. Addresses*  Letters of Initial Contact Mailed to 300 V.I. Addresses*  3 Weeks Later: Reminder Card Mailed to Same 250 Addresses*  3 Weeks Later: Reminder Card Mailed to Same 500 Addresses*  3 Weeks Later: Reminder Card Mailed to Same 1500 Addresses*  3 Weeks Later: Reminder Card Mailed to Same 300 Addresses*  Interested Subjects Contacted Study Coordinator  Interested Subjects Contacted Study Coordinator  Interested Subjects Contacted Study Coordinator  Interested Subjects Contacted Study Coordinator  Subjects Enrolled and Research Package Mailed  Subjects Enrolled and Research Package Mailed  Subjects Enrolled and Research Package Mailed  Subjects Enrolled and Research Package Mailed  Figure 1. Subject recruitment strategy. ‘*’ denotes mailing facilitated by the BC Ministry of Environment.  26
  2.3 Research Package Documents 
 A research package was mailed to each subject once they were enrolled in the study. The package contained the following documents, which are available in the Appendices J - M7: •  Consent Form (2 copies)  •  Study Instructions  •  Questionnaire Guide  •  Fish Consumption Guide  •  LifeLabs® Blood Requisition Form  •  BC Children’s and Women’s Hospital (BCCWH) Lab Requisition Form  •  Map of LifeLabs® locations on Vancouver Island  •  One postage-paid envelope  The purpose of this package was to ensure that each subject was as informed as possible about the proceedings of the study, as well as provide each subject with the required forms. The subjects received it prior to the telephone questionnaire and blood sample collection.  2.3.1 Consent Form 
 The consent form described the purpose of the study and outlined the risks and benefits of participating. Following subject enrollment, two copies of the form were mailed as part of the research package. Subjects were instructed to read and sign one of the forms and mail it back to the study coordinator in the postage-paid envelope where it was then signed by the coordinator. The other copy was to be kept for the subject’s records. While no aspect of the study began without the research package being received, in some cases, the questionnaire was administered before the study coordinator received the consent form back. If this were the case, it was confirmed with the subject prior to the commencement of the questionnaire that the consent form had been received, read and signed.  























































 7 LifeLabs® requisition forms and maps, as well as BCCWH requisition forms, are the property of their respective institutions and are not included in the Appendix. 27
  2.3.2 Study Instructions 
 The personally addressed cover letter included with each research package provided each subject with information on how the study would proceed over the following weeks. Participants were instructed to sign and mail back the study consent form first.  Completing the telephone  questionnaire was the second step in the study while travelling to a LifeLabs® location for the blood sample was the third and final step. To ensure each subject was as prepared as possible, and to minimize the length of each interview, the letter instructed subjects to review all of the documents prior to the questionnaire.  2.3.3 Questionnaire Materials 
 To assist the subjects in preparing for the questionnaire, as well as follow the progression of the interview over the telephone, a questionnaire guide was included in the research package. This abbreviated version included each question on the questionnaire in the appropriate order. The purpose of each question was explained as well as how it would be asked during the interview. Along with the questionnaire guide, a fish consumption guide was included in the research package. This document helped each subject to provide an accurate estimate of their fish meal portion sizes. It included photographs8 of two types of fish filets cut into six different portion sizes. The first set of photos was of salmon, representing a thick filet, while the second set was of rainbow trout, a thin filet. These two sizes of filets were provided in case an angler was more familiar with a thicker cut compared to a thinner cut or vice versa. Each set of filets contained six photos ranging from 75 g (one standard portion size) to 450 g (six standard portion sizes) in increments of 75 g. Fish filets were photographed on a standard-sized dinner plate (10¼ inches in diameter) for perspective.  























































 8
Using pictures in dietary questionnaires is a common and valid practice (Hankin, 1986; Lucas, et al. 1995)
 28
  2.3.4 Requisition Forms 
 A blood requisition form for LifeLabs® and a lab requisition form for BCCWH were also sent in the research package. LifeLabs® was contracted for the blood collection portion of the study because they have numerous locations throughout Vancouver Island. BCCWH was contracted for the analysis portion to ensure the standardization of all analyses, i.e. all of the samples were analyzed at the same facility under the same conditions. Subjects were instructed to take both forms to the LifeLabs® location of their choice for the blood sample collection. LifeLabs® then shipped to BCCWH for analysis.  2.4 Questionnaire Design 
 The questionnaire was administered over the telephone to quantitatively and qualitatively assess mercury exposures among Vancouver Island recreational anglers. The questionnaire contained 18 questions divided into six different sections (A through F) and focused on both dietary and non-dietary sources of mercury exposure. A copy of the questionnaire can be found in Appendix N. As opposed to other dietary assessment methods, such as food diaries or a 24-hour dietary recall, the dietary component of the questionnaire used a food frequency assessment. This was chosen as it was a good estimate of typical consumption patterns over a lengthy timeframe, was quick to administer, and did not require the subject to spend time recording their diet (Thompson & Byers, 1994).  2.4.1 Section A 
 The first section of the questionnaire contained four open-ended questions (#1-4), which focused on the demographics of the subject. These included the participant’s name, contact information, sex and date of birth.  2.4.2 Section B 
 The second section of the questionnaire contained one question (#5) that was designed to evaluate how often the anglers went fishing throughout the year regardless of whether they  29
  fished for harvest or catch and release. Subjects were asked to provide the number of days they had gone fishing per month over the past year, ending in the month that the questionnaire was conducted. This information was important for validating the timing of the data collection, i.e. June - November 2010, as studies indicate greater fish consumption and methylmercury body burden in the summer months (Johnsson et al., 2004; Kosatsky et al., 2000).  2.4.3 Section C 
 The third section of the questionnaire was designed to gather consumption information on recreationally caught fish only. Recreationally caught fish were defined as any fish personally caught by the angler, by any of the angler’s friends or family, or by any other person. This included any fish received as a gift. In general, caught fish were defined as a fish not purchased by the angler or any other person. There was one question in this section that contained three sub-questions (#6.0, 6.1 and 6.2), the purpose of which was to evaluate the three main determinants of mercury exposure from eating recreationally caught fish. The purpose of question 6.0 was to determine the frequency of total caught fish consumption over the past six months. All consumption questions were asked over the past six months at the time of the telephone interview. This was done for two reasons, the first of which was to maximize dietary recall accuracy.  Second, because the half-life of methylmercury is  approximately 50 days, it would take about six months for blood-mercury concentrations to reach steady-state (Stern, 1993; Kosatsky et al, 2000). Therefore, the results of the blood sample would adequately reflect steady-state blood-mercury levels as a result of consuming fish over the past six months. Answers to this question were close-ended with the following consumption frequency options: •  None  •  < Once/month  •  Once/month  •  Once every 2 weeks  •  Once/week  •  2 - 4 times per week  30
  •  > 4 times per week  Question 6.1 focused on the consumption frequency of specific caught fish species.  29  commonly caught freshwater and marine species, as identified through the BC Ministry of Environment (BC Ministry of Environment, 2007) and the Canadian Department of Fisheries and Oceans (Fisheries and Oceans Canada, 2009) were listed in this section.  During the  administration of the questionnaire, each of these species was mentioned to increase the accuracy of dietary recall.  If the subject responded to consuming that species, the following list of close-  ended consumption frequencies were provided: •  < Once/month  •  Once/month  •  Once every 2 weeks  •  Once/week  •  2 - 4 times per week  •  > 4 times per week  Following this list of 29 species, the subject was asked, open-ended, about any species they had consumed that were not mentioned.  If the participant identified another fish species, the  consumption frequency of this species was determined from one the above six options. Question 6.2 focused on the third determinant of exposure to mercury from fish consumption: portion size. For this question, participants were asked to refer the fish consumption guide (as outlined in section 2.3.3) and after choosing which type of cut they were most familiar with, either the thick or thin filets, to select the one photo that best represented the size of a typical meal of recreationally caught fish.  2.4.4 Section D 
 The fourth section of the questionnaire was designed to gather consumption information of commercially bought fish only. Commercial fish were defined as any fish purchased at a store, market or restaurant, which included any canned products as well as sushi and sashimi. Similar  31
  to Section C, there was one question in this section that contained three sub-questions (#7.0, 7.1 and 7.2), the purpose of which was to evaluate the three main determinants of mercury exposure from eating bought fish. The structure and purpose of these questions was the same as questions 6.0, 6.1 and 6.2 except they asked about commercial consumption. The only exception was the list of fish provided in question 7.1. In addition to most of the fish species listed in 6.1, common BC commercial species were identified from HealthLink BC (2011) as well as species identified from a survey of markets and grocery stores in Vancouver. This increased the number of species listed in question 7.1 to 38 from the 29 listed in question 6.1.  2.4.5 Section E 
 The fifth section of the questionnaire contained six questions (#8-13) that focused on other possible sources of exposure to mercury. Examining these exposures was necessary to determine whether blood-mercury results were a result of eating fish or from other sources. Question eight inquired about the occupation of the subject while question nine determined whether, over the past year, they had worked in: a chlor-alkali plant, a mercury mine or mine that uses mercury in the process of mining, a mercury processing facility, a facility that uses fluorescent tube compactors, a chemistry lab, a metal recycling facility and/or a dental office (with regular application of dental amalgams), since working in these areas carry a greater risk of mercury exposure. Questions 10-12 asked about common non-occupational exposures including the removal of dental amalgams, the use of mercury-containing paints and the use of mercurycontaining medications or supplements. Of particular concern were those individuals who may have a large number (> 8) of dental amalgams applied to their teeth, as these would be a primary source of (inorganic) mercury exposure (ATSDR, 1999).  These additional exposures not  attributed to fish intake were determined through the Agency for Toxic Substances and Disease Registry’s toxicological profile for mercury (ATSDR, 1999) and were necessary to ensure the accurate interpretation of the blood-mercury results. Finally, question 13 was an open-ended question for the subject to report any exposures to mercury that were not covered.  32
  2.4.6 Section F 
 The final section of the questionnaire contained questions 14-18. These questions were unrelated to fish consumption but were important for answering the research questions. They were asked last to increase the likelihood of the subjects answering the earlier questions. Question 14 was a close-ended question asking about the subject’s current fishing license status. The purpose of doing so was to determine how many of the anglers held both a freshwater fishing license and a federal saltwater license. Questions 15 and 16 inquired about the subject’s country of birth and parent’s country of birth. Due to the complexities in asking about ethnicity, it was decided that ethnicity would be determined by assessing countries of birth. Question 17 was an income question designed to determine the personal income of each subject. This question was based off of the standard personal income question from the Canadian Community Health Survey (Statistics Canada, 2009) where income referred to all sources including salary, wage, RRSPs, employment insurance, benefits, etc. The close-ended categories for this question were: •  < $20,000  •  $20,000 - $39,999  •  $40,000 - $59,999  •  $60,000 - $79,999  •  > $80,000  •  Decline  Question 18 was the final question and asked for the subject’s body weight. The purpose for this was to determine the effect of body weight on blood-mercury levels.  2.4.7 Questionnaire Pilot 
 The wording and format of the dietary portion of the questionnaire was based off of another food frequency questionnaire developed by Copes et al. (2008). Copes et al. (2008) used previously validated questions and formats from the National Institutes of Health Diet History Questionnaire DHQ-1 and the National Health and Nutrition Examination Survey III Food Frequency Questionnaire to evaluate exposure to cadmium as a result of consuming oysters. Since the questionnaire for our study also contained questions developed for the purpose of  33
  examining other sources of mercury exposure, it was pilot tested in person at a Vancouver angling store (10 test subjects) as well as over the telephone to five non-anglers. These two pilot populations were chosen because they encompassed individuals who came from various demographic backgrounds, who had a wide range of angling experience and knowledge, and who had differing fish consumption habits. The purpose of the pilot was to 1) determine whether the questions could be understood based on the level of the language and 2) whether the manner in which the questions were asked prompted the desired answer.  2.5 Data Collection 
 Once subjects were enrolled, a research package was mailed and a date for the telephone questionnaire was scheduled. Recruitment and data collection occurred from June - November 2010 in four waves until the target number of 200 study participants was attained. On the date and time of the questionnaire, I phoned the subject and administered the questionnaire, which took between 15 and 30 minutes depending on the subject. I conducted all telephone interviews. A script (see Appendix O) was created for the delivery of the questionnaire to ensure a standard interview was given to each subject. Following the interview, the subject was then instructed to take both of the requisition forms to the LifeLabs® of his or her choice to have the blood sample taken. Approximately 10 mL of blood was collected into a green-top sodium heparin tube and shipped to BCCWH for analysis. Samples were stored at -20 oC until they all reached BCCWH where they were analyzed for total blood-mercury, which is a typical practice when assessing blood-mercury levels since 95% of the mercury found in total-mercury blood samples exists as methylmercury (Kosatsky et al., 2000; Phelps et al., 1980; Al-Majed & Preston, 2000). Following dilution with alkaline triton X and gold in an n-butanol detergent, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was performed on each sample using a Perkin Elmer Elan 6100 DRC (Perkin Elmer, Waltham, MA). The limit of detection for this method was 2.5 nmol/L or 0.50 µg/L.  34
  2.6 Data Analysis 
 All statistical analyses were conduced using JMP version 8.0.2 for Mac (SAS Inc., Cary, NC, 2009). All questionnaires were sent to Express Data Ltd. (Vancouver, BC) with only the individual study ID (UBC-RAS-###) on the questionnaire for identification. Data was entered into Microsoft Excel (Microsoft Corp., Redmond, WA, 2007) using double entry. For the one subject who declined to provide her body weight, the mean value for all women participants was substituted.  2.6.1 Categorization of Fish Species 
 At the end of question 6.1, subjects were asked to list any fish species not previously mentioned. Because of the open-ended nature of the question, a variety of different recreationally caught species were reported, some of which were alternate names for previously mentioned fish. Prior to analysis, these species were placed into the appropriate categories: •  Caught snapper was recoded to caught rockfish o Pacific snapper is a common name for rockfish  •  Caught black bass was recoded to caught smallmouth bass  •  Caught pacific cod was recoded to caught cod  No re-coding was necessary for the reported consumption of bought fish species. This was because subjects may have had access to various species of bought fish both on and off the island. For example, while those that reported catching snapper (native to the Gulf of Mexico), actually caught rockfish, it was possible those who reporting buying snapper actually did so.  2.6.2 Coding of Fish Consumption Variables 
 To account for the effect of portion size on the frequency of fish consumption, portion size was integrated into fish consumption frequency and standardized to a mass of fish consumed per week. This was first accomplished by weighting each closed-ended consumption frequency to a mass per week estimate as demonstrated in Table 4.  35
  Table 4. Standardization of fish consumption frequencies to weekly consumption. Initial Consumption Frequency  Standardized Consumption Frequency  < Once/month  0.125 times/week  Once/month  0.25 times/week  Once every 2 weeks  0.5 times/week  Once/week  1/week  2 - 4 times/week  3 times/week  > 4 times/week  5 times/week  The standardized consumption frequencies presented in Table 4 were then multiplied by the respective portion sizes for each fish consumption variable to derive a mass of fish consumed per week. For example, a subject who reported consuming 225 g of Salmon > 4 times/week would have consumed an estimated 1125 g of salmon per week. 
 2.6.3 Coding of the Subject’s and Subject’s Parents’ Country of Birth 
 To evaluate the relationship between ethnicity, fish consumption and blood-mercury level, each subject was asked the country of birth for themselves and their parents. From this data, two ethnicity categories were created. The first categorized a subject as being from ‘Western’ descent if they reported being born in Canada or the United States, regardless of where their parents were born. For those not born in Canada or the US, they were categorized as ‘Other’. The second categorized them as ‘Western’ if they and at least one of their parents was born in either Canada or the United States. Subjects were categorized as ‘Other’ if they, or both of their parents were born outside of Canada and the US. The reason for categorization into only two categories, i.e. ‘Western’ or ‘Other’ was because the vast majority of subjects, and their parents, were born in Canada. Two variables were created for ‘Estimated Ethnicity’ to try and capture an accurate reflection of dietary habits. Table 5 demonstrates this categorization process. By asking for parent’s country of birth, we hoped to determine a certain type of diet since where a parent is born may be influential. We attempted to capture this in the variable ‘Estimated Ethnicity 2’.  36
  However, there was no sure way to guarantee this and therefore ‘Estimated Ethnicity 1’ was created, which assumed that diet type was only based on the subject’s country of birth. Table 5. Categorization of subject’s ethnicity based on their country of birth as well as their parents’ country of birth. Country of Birth  Variable  Subject  Mother  Father  Estimated Ethnicity 1  Estimated Ethnicity 2  Canada/US  Canada/US  Canada/US  Western  Western  Canada/US  Canada/US  Other  Western  Western  Canada/US  Other  Canada/US  Western  Western  Canada/US  Other  Other  Western  Other  Other  Canada/US  Other  Other  Other  Other  Other  Canada/US  Other  Other  Other Other Other Other Other Note: No subject was born outside of Canada/US with both parents born in Canada/US.  2.6.4 Descriptive Statistics and Bivariate Analyses 
 Univariate analyses were conducted for each categorical and continuous variable using JMP. The distribution of the blood-mercury data was also determined. This included the creation and examination of histograms and scatter plots as well as the calculation of the measures of central tendency. Bivariate analyses were then conducted to evaluate the independent relationship between each variable and blood-mercury level as well as between fish consumption frequencies and relevant demographic variables.  For categorical variables, these included t-tests and  analyses of variance (ANOVA), where applicable. For example, t-tests were conducted to determine differences in blood-mercury levels between each category within the variables ‘Sex’, ‘Estimated Ethnicity 1’ and ‘Estimated Ethnicity 2’. The null hypothesis (H0) for these tests was that there was no difference between the means in each category while the alternate hypothesis (H1) was that there was a difference between the means (α = 0.05). ANOVA was performed for our income variable because it consisted of more than two categories. A Tukey’s post-hoc test was only conducted if the model was significant to α = 0.05. The purpose of this was to determine which categories were significantly different from each other within the income  37
  variable. For continuous variables, simple linear regression was performed. The H0 for these tests was that the slope of the relationship between these variables and blood-mercury was zero, while the H1 was that the slope of the relationship differed from zero (α = 0.05).  2.6.5 Multiple Linear Regression 
 Prior to the creation of the multiple linear regression model, a parametric test of correlation was conducted between each continuous variable. The primary purpose of this was to determine which fish species, if any, were being consumed in similar patterns to the point where it would be difficult to determine which variable was responsible for exposure. A Pearson coefficient of |r| = 0.6 was used for these tests. For pairs of variables that were correlated by ≥ 0.6, only one of the two was included in the final model. Priority was given to the variable that was significant to α = 0.05 in simple linear regression. If both (or none) were significantly related with bloodmercury in bivariate analysis, the variable that best addressed the research questions was offered to the model. Following correlation, a multiple regression model was created that included the relevant caught fish species, bought fish species and demographic variables.  2.7 Subject Follow-Up 
 Following the completion of the blood sample analysis, personal blood sample results were sent to the subjects along with an explanation of what they meant. Two drafts of the letter were created. The first was sent to subjects who had a blood-mercury level < 10 µg/L. This letter provided a general description of the state of blood-mercury levels in Canada and offered a link to the HealthLink BC webpage for more information on mercury. This blood-mercury cutoff was chosen because it was half of the Health Canada blood-mercury guideline of 20 µg/L. The second follow-up letter was sent to those subjects with a blood-mercury level ≥ 10µg/L. This response was more personal with a description of the subject’s reported fish consumption patterns that may be contributing to an elevated result. Methods for reducing exposure were provided in both letters and focused on limiting frequent consumption of species known to contain concerning levels of mercury. Both letters also included an offer to forward the results to the subject’s family physician should they desire. Copies of both of these letters are available  38
  in Appendices P and Q respectively. Accompanying the results letter was a copy of the fully signed consent form as well as a $25 gift card to a Vancouver Island sport-fishing store.  39
  3. Results 
 A total of 2550 recruitment letters were sent to eligible anglers residing on Vancouver Island with 182 of these being returned to the study undelivered. Overall, 222 participants responded (a 9.4% response rate) with 198 fully completing the study (a 89.2% completion rate). The 24 who did not complete the study either withdrew prior to the administration of the questionnaire or completed the questionnaire but did not provide a blood sample. Of the 198 who completed the study three were spousal enrollments, i.e. they heard of the study from their partner and were eligible to participate, but did not personally receive a letter. These subjects were tentatively enrolled to help ensure enough participants were recruited; however, they were not included in the final study population as enough subjects were recruited and including them would 1) compromise the random sampling strategy and 2) would not have significantly influenced the data. Therefore, the final number of subjects who completed the questionnaire and provided a blood sample was 195 (Figure 2).  40
  2250 Recruitment Letters Mailed  182 Undelivered Letters  222 Responses (9.4% Response Rate)  24 Withdrew or Lost to Follow-Up  198 Completed Questionnaires & Blood Samples (89.2% Completion Rate)  3 Spousal Enrollments Dropped  Final Study Population N = 195  Figure 2. Study population recruitment.  3.1 Blood-Mercury Concentrations 
 The limit of detection (LOD) for the ICP-MS method conducted by the lab at BCCWH was 0.50 µg/L. Ten of the 195 blood samples were below this concentration. They were replaced by 0.35 µg/L (equal to LOD/√2) for all data analyses. This value was chosen, as opposed to using 0.25 µg/L (equal to LOD/2), because the geometric standard deviation of the blood mercury results was < 3.0 (Hornung & Reed, 1990).  41
  By examining the geometric mean (2.33 µg/L), the skewness and kurtosis of the blood-mercury distribution, as well as the quantile plots9, it was determined that the data followed a lognormal distribution. Therefore, each blood-mercury result was log-transformed for analysis (Table 6). Table 6. Blood-mercury concentrations in the study population. N Blood-Hg 195 Concentration * LOD = 0.50 µg/L  Arithmetic Mean (µg/L)  Geometric Mean (µg/L)  Geometric Standard Deviation  Min. (µg/L)  Max. (µg/L)  % <LOD*  3.05  2.33  2.16  <0.50  15.1  5.13  3.2 Study Population 
 3.2.1 Characteristics of the Study Sample 
 The following characteristics of the study sample are reported in Table 7: sex, annual personal income, current fishing license status, estimated ethnicity and island region of residence. Age and body weight are reported in Table 8 and subject’s and subject’s parents’ countries of birth are reported in Table 9. The ‘typical’ study participant was male, born in Canada (parents also born in Canada), 55 years old, 83.6 kg, lived in the central region of Vancouver Island, earned $20,000 - $39,999 annually (the most frequently reported income category) and held both a BC freshwater fishing license and a federal saltwater fishing license.  























































 9 A detailed explanation of how the distribution was determined to be lognormal can be found in Appendix B. 42
  Table 7. Sample characteristics: sex, annual personal income, current fishing license status, island region of residence and estimated ethnicity. Number  Percent  195  100  Central  97  49.7  South  77  39.5  Pacific Rim  16  8.2  North  5  2.6  Male  156  80.0  Female  39  20.0  < $20,000  24  12.3  $20,000 - $39,999  59  30.2  $40,000 - $59,999  45  23.1  $60,000 - $79,999  29  14.9  > $80,000  31  15.9  Decline  7  3.6  BC Freshwater & Federal Saltwater  119  61.0  BC Freshwater Only  43  22.1  Federal Saltwater Only  16  8.2  None  17  8.7  Western  175  89.7  Other  20  10.3  Western  156  80.0  Other  39  20.0  All Recreational Anglers Island Region of Residence  Sex  Annual Income  Fishing License Status at Time of Questionnaire  Estimated Ethnicity 1  Estimated Ethnicity 2  43
  Table 8. Study population age and body weight stratified by sex (N = 195).  Age (years)  Arithmetic Mean 55.0  Arithmetic Standard Deviation 14.7  Min.  Median  Max.  21  57  85  Male  56.7  14.5  21  59.5  85  Female  48.1  13.6  21  51  71  47.7  83.1  136.2  Body Weight (kg)  83.6  15.4  Male  86.8  14.6  56.8  84.0  136.2  Female  71.0  11.7  47.7  70.4  95.3  44
  Table 9. Subject’s and subject’s parents’ countries of birth (N = 195). Subject Country of Birth  Mother  Father  Number  Percent  Number  Percent  Number  Percent  Canada  172  88.2  139  71.3  133  68.2  England  10  5.1  23  11.8  22  11.3  United States  3  1.5  6  3.1  9  4.6  China  3  1.5  2  1.0  2  1.0  Germany  2  1.0  5  2.6  5  2.6  Austria  1  0.5  1  0.5  2  1.0  France  1  0.5  3  1.5  2  1.0  New Zealand  1  0.5  0  0.0  0  0.0  Norway  1  0.5  2  1.0  2  1.0  Scotland  1  0.5  2  1.0  3  1.5  Australia  0  0.0  1  0.5  0  0.0  Denmark  0  0.0  1  0.5  1  0.5  India  0  0.0  1  0.5  1  0.5  Ireland  0  0.0  1  0.5  1  0.5  Netherlands  0  0.0  3  1.5  3  1.5  Poland  0  0.0  1  0.5  2  1.0  Ukraine  0  0.0  2  1.0  1  0.5  Wales  0  0.0  1  0.5  0  0.0  Western Samoa  0  0.0  1  0.5  1  0.5  Sweden  0  0.0  0  0.0  1  0.5  Switzerland  0  0.0  0  0.0  1  0.5  Yugoslavia  0  0.0  0  0.0  1  0.5  Croatia  0  0.0  0  0.0  1  0.5  Finland  0  0.0  0  0.0  1  0.5  45
  It was important to compare the study population demographics with those of the BC MoE licensing list to determine how well our population reflected all Vancouver Island anglers. Unfortunately, a demographic break down of the freshwater fishing license list was unavailable for comparison. However, an assessment of the state of the BC freshwater fishing industry in 2005 prepared for the Freshwater Fisheries Society of BC by GSGislason & Associates Ltd. et al. (2009) outlined the demographic of recreational anglers throughout all of British Columbia. Assuming that demographic trends are constant throughout the province, the study population compared relatively well to the typical recreational angler in terms of sex. The study population contained 80% males and 20% females while for all BC anglers, the split was 81.2% male and 18.8% female. However, there was a larger discrepancy when considering age as demonstrated in Table 10. Table 10. Comparison of angler ages between the study population and all BC recreational anglers. BC angler ages were obtained from a consulting report conducted by GSGislason & Associates Ltd. et al. (2009). Age in Years (% of the Population) 19 - 24  25 - 34  35 - 44  45 - 54  > 55  Study  1.50  10.8  11.8  22.1  53.8  Mean (Years) 55.0  All BC Anglers  3.40  9.70  18.2  29.2  39.5  50.5  Population  3.2.2 Blood-Mercury Concentrations and Demographic Variables To investigate our demographic factors when considering blood-mercury concentrations, the number of observations, arithmetic mean, geometric mean, geometric standard deviation, minimum value, maximum value and percent of blood-mercury results below the LOD were calculated for the categorical variables sex, annual income and estimated ethnicity (Table 11). There was no significant difference between the means of each category for ‘Sex’, ‘Estimated Ethnicity 1’ and ‘Estimated Ethnicity 2’ (p > 0.05). Similarly, for ‘Annual Income’, there were no significant differences in blood-mercury between the six income categories (p > 0.05).  46
  Table 11. Blood-mercury concentrations stratified by sex, annual income and estimated ethnicity. N  Arithmetic Mean (µg/L)  Geometric Mean (µg/L)  Geometric Standard Deviation  Min. (µg/L)  Max. (µg/L)  % <LOD*  195  3.05  2.33  2.16  <0.50  15.1  5.13  Male  156  3.11  2.38  2.16  <0.50  15.1  4.10  Female  39  2.79  2.12  2.17  <0.50  9.9  1.03  < $20,000  24  2.30  1.73  2.24  <0.50  6.4  1.03  $20,000 - $39,999  59  3.06  2.27  2.28  <0.50  11.1  2.05  $40,000 - $59,999  45  2.88  2.29  1.95  <0.50  12.2  0.51  $60,000 - $79,999  29  2.64  2.25  1.85  <0.50  8.6  0.51  > $80,000  31  4.20  3.24  2.21  <0.50  15.1  0.51  Decline  7  3.20  2.27  2.85  <0.50  6.5  0.51  Western  175  2.92  2.24  2.15  <0.50  15.1  5.13  Other  20  4.13  3.19  2.13  0.90  12.2  0.0  Western  156  2.85  2.22  2.14  <0.50  11.1  5.13  Other  39  3.85  2.78  2.24  0.69  15.1  0.0  Blood-Hg Concentration Sex1  Annual Income2  Estimated Ethnicity 13  Estimated Ethnicity 24  α = 0.05 * LOD = 0.50 µg/L 1 No statistical difference between the geometric means of ‘Male’ and ‘Female’ (p = 0.41) 2 No statistical differences between the geometric means of the annual income categories (p = 0.09) 3 No statistical difference between the geometric means of ‘Western’ and ‘Other’ (p = 0.052) 4 No statistical difference between the geometric means of ‘Western’ and ‘Other’ (p = 0.11)  Age (at the time of the blood sample) and body weight were two of our continuous variables. Simple linear regression was conducted for each variable to determine whether there was an association between age and blood-mercury or between body weight and blood-mercury. While there was an increasing trend in blood-mercury as age increased (slope = 0.01 µg/L/year), the slope was not significantly different from zero (p = 0.07). There was a decreasing trend in  47
  blood-mercury as body weight increased (slope = -0.04 µg/L/kg), but the slope was also not significantly different from zero (p = 0.27).  3.2.3 Total Recreationally Caught Fish Consumption and Demographic Variables 
 Table 12 demonstrates the relationship between total caught fish consumption and our demographic variables. Females consumed significantly more caught fish than males (390 g/week vs. 240 g/week respectively). In addition, significant differences in fish consumption were found between the income range of < $20,000 (most fish consumption) and $60,000 $79,999 (least fish consumption). There were no statistical differences in fish consumption by ethnicity.  48
  Table 12. Total caught fish consumption stratified by sex, annual income and ethnicity. N Total Recreational Fish Consumption Sex1  Arithmetic Mean Arithmetic (g/week) Standard Deviation  Min. (g/week)  Max. (g/week)  195  270  330  0  1500  Male  156  240  310  0  1500  Female  39  390  390  0  1350  < $20,000  24  450A  460  0  1350  $20,000 - $39,999  59  300  370  0  1500  $40,000 - $59,999  45  220  280  0  1125  $60,000 - $79,999  29  160B  240  0  1125  > $80,000  31  260  280  0  1125  Decline  7  270  220  19  675  Western  175  270  340  0  1500  Other  20  260  310  0  900  Western  156  260  320  0  1500  Other  39  320  400  0  1350  Annual Income2  Estimated Ethnicity 13  Estimated Ethnicity 24  α = 0.05 1 Statistical difference between the arithmetic means of ‘Male’ and ‘Female’ (p = 0.01) 2 Statistical difference between the arithmetic means of the annual income categories (p = 0.04) A The arithmetic mean of ‘< $20,000’ is statistically different than the mean of ‘$60,000 - $79,999’ B The arithmetic mean of ‘$60,000 - $79,999’ is statistically different that then mean of ‘< $20,000’ 3 No statistical difference between the arithmetic means of ‘Western’ and ‘Other’ (p = 0.84) 4 No statistical difference between the arithmetic means of ‘Western’ and ‘Other’ (p = 0.31)  Simple linear regression was also conducted between age and total caught fish consumption to determine whether there was an age related difference in the amount of fish eaten. While we observed an increasing trend (slope = 0.49 g/week/year) in total recreational fish consumption as age increased, the slope was not significantly different form zero (p = 0.77).  49
  3.2.4 Total Commercially Bought Fish Consumption and Demographic Variables 
 Table 13 illustrates the relationship between total bought fish consumption and our demographic variables. There was no significant difference in total commercial fish consumption by sex, income or ethnicity. Table 13. Total bought fish consumption stratified by sex, annual income and ethnicity. N Total Commercial Fish Consumption Sex1  Arithmetic Mean Arithmetic (g/week) Standard Deviation  Min. (g/week)  Max. (g/week)  195  270  330  0  1875  156  280  340  0  1875  39  210  260  9.4  1125  < $20,000  24  270  380  19  1350  $20,000 - $39,999  59  200  260  0  1125  $40,000 - $59,999  45  250  300  0  1350  $60,000 - $79,999  29  400  430  0  1875  > $80,000  31  300  310  28  1125  7  330  300  38  900  175  270  330  0  1875  20  290  330  0  900  Western  156  260  320  0  1875  Other  39  290  340  0  1350  Male Female 2  Annual Income  Decline 3  Estimated Ethnicity 1 Western Other  4  Estimated Ethnicity 2  α = 0.05 1 No statistical difference between the arithmetic means of ‘Male’ and ‘Female’ (p = 0.20) 2 No statistical difference between the arithmetic means of the annual income categories (p = 0.18) 3 No statistical difference between the arithmetic means of ‘Western’ and ‘Other’ (p = 0.77) 4 No statistical difference between the arithmetic means of ‘Western’ and ‘Other’ (p = 0.72)  50
  Further, while we observed an increasing trend in total commercial fish consumption as age increased (slope = 1.50 g/week/year), the slope was not significantly different from zero (p = 0.35).  3.3 Recreational Fishing Frequency 
 To determine whether the sampling period captured the seasonality of recreational fishing, subjects were asked to report the number of days they had gone fishing over the past 12 months at the time of the questionnaire. To increase the accuracy of reporting, only the last full month of fishing was included in the analysis. For example, if a subject was interviewed in August, only the number of days the participant went fishing in July was included to ensure the days fished in August were not underrepresented. As Figure 3 illustrates, fishing occurred the most in the summer and least in the winter.  Recreational
Fishing
Frequency
Between
May
2009

and
 October
2010
 Mean
Fishing
Days/Month
  6.0
 5.0
 4.0
 3.0
 2.0
 1.0
 0.0
  Month
­
Year
  Figure 3. Mean number of recreational fishing days per month between May 2009 and October 2010.  51
  3.4 Portion Size and the Frequency of Total Fish Consumption: Caught and Bought 
  3.4.1 Portion Size 
 Subjects were asked to report a typical portion size for both recreationally caught and commercially bought fish species. This estimate was not species-specific, i.e. it was one average portion size for caught fish and one for bought fish.  Figure 4 describes the number of  observations for each reported portion size. In general, anglers consumed smaller portion sizes of bought fish and larger portion sizes of caught fish.  Portion
Size
 70
  Number
of
Observations
  60
 50
 40
 Caught
  30
  Bought
 20
 10
 0
 75
  150
  225
  300
  375
  450
  Portion
Size
(g)
  Figure 4. Portion sizes for recreationally caught (grey) and commercially bought (black) fish (N = 195).  52
  3.4.2 Frequency of Total Fish Consumption: Caught and Bought 
 Total fish consumption frequency, regardless of species, was examined to determine the differences between caught and bought fish consumption. Figure 5 illustrates the number of anglers, in each consumption frequency category, who reported eating caught or bought fish, regardless of species, over the past six months at the time of the questionnaire. In general, there was more variation among anglers consuming caught fish as relatively equal numbers of subjects ate these fish between the frequencies of < once/month and 2 - 4 times/week. In contrast, many more anglers reported consuming bought fish at the higher frequencies, i.e. once every two weeks to 2 - 4 times/week. Few anglers reported consuming fish at the extremes, i.e. none and > 4 times/week. Fourteen anglers reported consuming no recreational fish while five did not eat any commercial fish, however all anglers consumed at least one type of fish.  Total
Fish
Consumption
 70
  Number
of
Observations
  60
 50
 40
 Caught
  30
  Bought
 20
 10
 0
 None
  <1/Month
 1/Month
 1/2
Weeks
 1/Week
 2‐4/Week
 >4/Week
  Frequency
of
Total
Fish
Consumption
  Figure 5. Frequency of total fish consumption of recreationally caught (grey) and commercially bought (black) species, regardless of species (N = 195).  53
  3.4.3 Aggregation of Portion Size and the Frequency of Fish Consumption 
 When comparing portion size (Figure 4) and total fish consumption (Figure 5), it was clear that anglers did not eat commercially bought and recreationally caught fish in equal frequencies or amounts. The majority of anglers consumed bought fish species more than once every two weeks, however did so in smaller portions. Compared to bought consumption, more anglers reported eating caught fish at lower frequencies but did so in greater portion sizes. Since frequency and portion size influence mercury exposure, we combined these two variables to create a fish consumption estimate in grams of fish consumed per week (Table 14). Once these two determinants of exposure where combined, it became clear that the population consumed caught and bought fish in equal quantities. Table 14. Total caught and bought fish consumption in grams of fish per week (N = 195).  Caught  Arithmetic Mean Arithmetic (g/week) Standard Deviation 270 330  Median (g/week) 150  Min. (g/week) 0  Max. (g/week) 1500  Bought 270 330 150 0 1875 
 
 Simple linear regression was then used to examine the relationships between total caught fish or total bought fish consumed and blood-mercury levels (Table 15). Blood-mercury levels per g/week caught were almost double of those per g/week bought, though one can see the model for caught was a better fit (significant, adjusted R2 = 0.034). Table 15. Association between blood-mercury levels and total caught and total bought fish consumption. Total Fish Consumption (g/week) Caught Bought * α = 0.05  Coefficient (ln µg/L blood-Hg per g/week) 4.6 x 10-4 2.9 x 10  -4  Standard Error  Model P-Value*  Adjusted R2  1.6 x 10-4  0.006  0.034  -4  0.087  0.001  1.7 x 10  
  54
  3.5 Species-Specific Fish Consumption: Caught and Bought 
 3.5.1 Recreationally Caught Fish Consumption 
 After re-coding for potentially duplicate species of fish, 28 different recreationally caught species were consumed in varying frequencies. The percentage of the population who reported consuming each species is available in Appendix C (Table 24). Of these 28 species, only those reported by ≥ 5% of population were analyzed further since it would be difficult to derive definitive conclusions from fish species with fewer observations. The frequency of consumption for the nine fish species that were reported by ≥ 5% of the anglers is presented in Table 16. Table 16. Number of observations for each consumption frequency of the recreationally caught fish species reported by ≥ 5% of the study population (N = 195). Consumption Frequency (Ranked from Most Consumed to Least Consumed) Fish Species Salmon  None *  <1/Month 1/Month  1/ 2 Weeks  1/Week  2-4/Week  >4/Week  34  38  30  34  37  21  1  Shellfish Rainbow Trout Halibut  77  48  39  20  6  5  0  107  46  30  9  1  2  0  117  44  22  7  4  1  0  Lingcod  143  29  14  7  3  0  0  0  0  0  0  1  0  0  0  Rockfish 149 24 13 7 2 Cutthroat 152 26 14 3 0 Trout Albacore 184 5 4 0 1 Tuna Steelhead 185 5 5 0 0 Trout * Shellfish includes shrimp, prawns, crabs, mussels, oysters and clams  Similar to overall fish consumption, consumption frequencies were converted to grams of fish consumed per week. Summary statistics were calculated for both the total study population as well as for only the consumers of each species (Table 17). Examining the consumers of each species emphasizes the effect that portion size has on the frequency of consumption. For  55
  example, over the entire population, an average of 11 ± 100 g of albacore tuna was consumed per week. However, the 5.6% of the population that did consume this species ate an average of 200 ± 400 g/week. However, this effect was less dramatic for a popular species such as salmon where removing non-consumers only increased the amount consumed by amount 40 g/week.  Table 17. Recreational fish consumption in grams/week for caught species reported by ≥ 5% of the study population (N = 195) along with the percent of subjects who reported eating each species. Consumption is reported for the entire study population as well as for only those subjects who ate each species.  Fish Species Salmon  Percent of Study Population 83  Study Population Arithmetic Arithmetic Mean Standard (g/week) Deviation 200 280  Consumers Only Arithmetic Arithmetic Mean Standard (g/week) Deviation 240 300  Shellfish* Rainbow Trout Halibut  61  68  160  110  190  45  34  79  75  100  40  31  81  78  110  Lingcod  27  18  42  68  56  71  64  55  37  200  400  64  40  Rockfish 24 17 43 Cutthroat 22 12 28 Trout Albacore 5.6 11 100 Tuna Steelhead 5.1 3.3 17 Trout * Shellfish includes shrimp, prawns, crabs, mussels, oysters and clams  3.5.2 Commercially Bought Fish Consumption 
 Fifty-two different commercially bought species were consumed in varying frequencies. The percentage of the population who reported consuming each species is available in Appendix D (Table 25). Of these 52 species, only those reported by ≥ 5% of population were analyzed further. The frequency of consumption for these 20 fish species is presented in Table 18.  56
  Table 18. Number of observations for each consumption frequency of the commercially bought fish species reported by ≥ 5% of the study population (N = 195). Consumption Frequency (Ranked from Most Consumed to Least Consumed) Fish Species Shellfish*  None  <1/Month 1/Month  1/ 2 Weeks  1/Week  2-4/Week  >4/Week  62  59  46  15  9  4  0  Halibut  71  65  38  17  4  0  0  Salmon Canned Other+ Tuna Sardine Canned Albacore Tuna Cod  72  39  31  24  23  6  0  121  24  21  16  9  2  2  121  39  18  10  4  3  0  124  18  23  17  7  6  0  131  37  17  10  0  0  0  Sole  132  44  10  4  5  0  0  Snapper  142  29  18  5  1  0  0  Pollock  144  29  15  4  2  1  0  Lingcod  152  22  14  5  1  1  0  Herring Processed Fish Other+ Tuna^ Basa Albacore Tuna^ Sablefish  156  24  4  4  5  0  2  159  29  4  2  1  0  0  162  20  6  4  2  1  0  165  23  4  3  0  0  0  171  9  10  1  2  2  0  174  20  0  1  0  0  0  Tilapia 174 17 2 1 1 0 Mahi 176 16 3 0 0 0 Mahi Rainbow 180 11 4 0 0 0 Trout * Shellfish includes shrimp, prawns, crabs, mussels, oysters and clams + ‘Other’ refers to species that are not albacore, i.e. skipjack, yellowfin, ahi, etc. ^ Fresh or frozen  0 0 0  57
  After incorporating portion size with consumption frequency estimates (Table 19), salmon, as was the case for caught fish, remained the most commonly consumed species of bought fish. Those who consumed both types of canned tuna ate approximately one standard can per week. Consumption of canned tuna was much more common than fresh/frozen tuna. Comparing Tables 17 and 19, those who consumed caught albacore tuna ate about double the mass each week compared to those who ate bought albacore.  58
  Table 19. Commercial fish consumption in grams/week for bought species reported by ≥ 5% of the study population (N = 195) along with the percent of subjects who reported eating each species. Consumption is reported for the entire study population as well as for only those subjects who ate each species.  Fish Species Salmon  Percent of Study Population 63  Study Population Arithmetic Arithmetic Mean Standard (g/week) Deviation 80 160  Consumers Only Arithmetic Arithmetic Mean Standard (g/week) Deviation 130 180  Shellfish* Canned Other+ Tuna Canned Albacore Tuna Halibut  68  56  120  82  140  38  52  180  140  280  36  44  120  120  170  64  38  59  60  64  Sardine  38  33  100  86  160  Herring  20  28  170  140  360  Sole  32  18  45  54  65  Cod  33  17  34  52  42  Lingcod  22  16  58  74  110  Pollock  26  16  69  62  130  Snapper Albacore Tuna^ Other+ Tuna^ Processed Fish Basa  27  14  31  52  39  12  12  63  99  160  17  12  47  69  96  19  8.9  32  48  68  15  5.9  16  38  22  Tilapia  11  5.5  26  51  65  Mahi Mahi  9.7  3.8  13  39  21  Sablefish 11 3.7 14 34 Rainbow 7.7 2.9 12 38 Trout * Shellfish includes shrimp, prawns, crabs, mussels, oysters and clams + ‘Other’ refers to species that are not albacore, i.e. skipjack, yellowfin, ahi, etc. ^ Fresh or frozen  28 22  59
  3.5.3 Blood-Mercury Levels and Consumption of Individual Fish Species 
 Simple linear regression was conducted for each fish species, both recreationally caught and commercially bought, that were reported by ≥ 5% of the study population. The purpose was to evaluate the relationship between the consumption of individual fish species and blood-mercury concentration. The full results of these tests are available in Appendix E (Table 26), however Table 20 outlines the coefficient, standard error, p-value, and model variability for the species whose associations had p ≤ 0.3. Table 20. Associations between blood-mercury levels and species-specific fish consumption for the caught and bought fish species reported by ≥ 5% of the study population and with p ≤ 0.3. Species are listed in order of descending adjusted R2 values. Coefficient (ln µg/L Blood-Hg per g/week)  Standard Error  Model P-Value*  Adjusted R2  Caught Lingcod  4.1 x 10-3  1.3 x 10-3  0.002  0.045  Caught Rockfish  3.9 x 10-3  1.3 x 10-3  0.002  0.043  -3  -3  0.002  0.042  2.6 x 10-3  8.6 x 10-3  0.003  0.039  -3  -4  0.004  0.037  Fish Species  +  Bought Other Tuna  ^  Bought Albacore Tuna^  3.6 x 10  1.2 x 10  Caught Halibut  2.0 x 10  Caught Shellfish*  9.4 x 10-4  3.4 x 10-4  0.007  0.033  -3  1.8 x 10  -3  0.036  0.018  3.3 x 10  -4  0.070  0.014  3.5 x 10  -4  0.104  0.009  1.9 x 10  -4  0.126  0.007  4.7 x 10  -3  0.138  0.006  9.4 x 10  -4  0.148  0.006  Bought Snapper Bought Herring  3.8 x 10  -5.9 x 10  -4  6.7 x 10  5.8 x 10  -4  3.0 x 10  -4  7.0 x 10  -3  Bought Halibut  1.4 x 10  -3  Caught Cutthroat Trout  2.7 x 10-3  2.0 x 10-3  0.174  0.004  -3  -3  0.187  0.004  Bought Salmon Caught Salmon Bought Rainbow Trout  Bought Sablefish  5.3 x 10  Caught Steelhead Trout  -4.2 x 10-3  3.3 x 10-3  0.209  0.003  -3  -4  0.227  0.002  1.2 x 10-3  0.274  0.001  Bought Lingcod  1.2 x 10  Bought Sole  1.4 x 10-3  4.0 x 10  9.5 x 10  *  α = 0.05 Shellfish includes shrimp, prawns, crabs, mussels, oysters and clams + ‘Other’ refers to species that are not albacore, i.e. skipjack, yellowfin, ahi, etc. ^ Fresh or frozen *  60
  The effect of consuming certain fish species on blood-mercury levels was evident upon examining the three subjects with the highest blood-mercury concentrations. These subjects (all of whom were either women ≥ 50 years old or men > 18 years old) were of specific interest because each had a blood-mercury concentration > 10 µg/L, the level where investigation10 of possible exposures should take place (Brodkin et al., 2007). The highest blood-mercury level was 15.1 µg/L. This subject reported consuming 230 g/week of fresh/frozen bought other tuna, mostly in the form of sushi. The second highest blood-mercury level was 12.2 µg/L. This subject reported consuming no commercial fish but ate 300 g of caught rockfish per week. The final subject had a blood-mercury level of 11.1 µg/L and consumed 680 g of fresh/frozen bought albacore tuna per week and 900 g of caught halibut per week. None of these subjects reported any other sources of mercury exposure.  3.6 Other Exposure Information 
 To assess the possibility of occupational exposures, subjects were asked their occupation. These occupations were then classified by WorkSafeBC sub-sectors (WorkSafeBC, 2011) or by another appropriate category such as unemployed, student, retired, on disability or employed by the federal government.  The majority of subjects (85/195), were retired at the time of the  questionnaire as demonstrated in Figure 6. No significant differences were found between these occupations with respect to blood-mercury levels.  























































 10 As opposed to intervention, which Legrand et al. (2010) suggest should begin at a bloodmercury level of 20 µg/L for women ≥ 50 years old and men > 18 years old. 61
  Number
of
Observations
  Study
Population
Occupation
 90
 80
 70
 60
 50
 40
 30
 20
 10
 0
  Occupation
  Figure 6. Occupations of the 195 study participants. 
 Following the open-ended question asking about their current occupation, eight occupations of specific concern were listed to determine whether the subjects had worked in any of these areas over the past year at the time of the questionnaire. These eight areas were: a chlor-alkali plant, a mercury mine or mine that uses mercury in the process of mining, a mercury processing facility, a facility that uses fluorescent tube compactors, a chemistry lab, a metal recycling facility and/or a dental office (with regular application of dental amalgams). Five of the 195 respondents reported working in one of these areas in the past year while a sixth, an electrician, reported working in three areas. As Table 21 demonstrates, the blood-mercury levels of these subjects were relatively low. However, the electrician had a blood-mercury level of 7.40 µg/L; although he consumed 56 g/week of caught lingcod and 19 g/week of fresh/frozen bought other tuna.  62
  Table 21. Blood-mercury results for the six subjects who reported working in any of the eight occupational areas of concern over the past year at the time of the questionnaire. Results are ranked by blood-mercury level, highest to lowest. Subject  Blood-Mercury Concentration (µg/L)*  1  7.40  2  3.11  Occupational Area(s) of Concern Chlorine Production Facility Dental Office Metal Recycling Facility Dental Office  3  2.68  Chemistry Lab  4  1.47  Dental Office  5  0.85  Chlorine Production Facility  <0.50  Metal Recycling Facility  *  6 LOD = 0.50 µg/L  Examining other possible sources of exposure to mercury, 62.1% of the population reported having silver dental amalgams currently applied to their teeth. However only 5.1% reported having any of them removed in the past three months. There was no significant difference in blood-mercury level between those who had fillings removed and those who did not (p-value > 0.05). Further, 40.5% reported having painted in the past six months but none recalled any of the paint containing mercury. None of the subjects reported taking any therapeutic or nutritional medications/supplements that contained mercury. Nine of the 195 subjects reported past, i.e. more than a year at the time of the questionnaire, exposure to mercury either through their occupation or their lifestyle. As illustrated in Table 22, the majority of these subjects had low blood-mercury concentrations. However, one angler who previously worked in a pulp and paper mill for 25 years had a blood-mercury concentration of 7.00 µg/L; although he also consumed 230 g of caught rockfish per week and 110 g of caught lingcod per week. Another subject used to live in a gold camp and 10 years ago had eight silver dental amalgams removed all at once, which resulted in him having to undergo mercury chelation therapy. He had a blood-mercury level of 6.70 µg/L and consumed mostly caught salmon and caught halibut.  63
  Table 22. Blood-mercury results for the nine subjects who reported past exposures to mercury. Results are ranked by blood-mercury level, highest to lowest. Subject  Blood-Mercury Concentration (µg/L)*  1  7.00  2  6.70  3  2.96  4  2.72  5  2.14  6  1.93  -Worked with mercury-containing instruments -Pulp mill worker -Worked with mercury-containing instruments -Worked with mercury-containing instruments  7  1.92  -Brief contracting work in a pulp mill  8  1.05  -Worked with liquid mercury  0.90  -Briefly worked in a chlorine production facility  *  9 LOD = 0.50 µg/L  Past Mercury Exposure -Pulp and paper mill worker (25 years) -Used to live in a gold mining camp -Eight dental amalgams removed at once in 2000 -Underwent mercury chelation therapy -Worked in a chemistry lab  3.7 Multiple Linear Regression 
 To determine how the frequency of consumption, the mass of fish consumed and the species of fish consumed affect blood-mercury concentrations in the Vancouver Island study population, we developed a multiple regression model.  3.7.1 Correlation 
 Following parametric correlation between independent continuous variables, only one pair of continuous variables was significantly (α = 0.05) correlated to |r| ≥ 0.6: •  Caught salmon and total caught fish consumption (r = 0.83)  The results of the correlation demonstrated there was some dependency between caught salmon and total caught fish consumption, which was likely because > 80% of the population reported eating recreationally caught salmon. Since salmon contains low levels of mercury, caught  64
  salmon was excluded from the model in favor of total caught fish consumption, which was shown to be significant in simple linear regression.  3.7.2 Criteria for Inclusion into the Model 
 A number of criteria were considered for model inclusion. These were primarily for statistical considerations but also to ensure the research questions were addressed. The criteria for model development were as follows:  •  Inclusion of fish consumption variables where ≥ 5% of the study population responded  •  Inclusion of variables that were not correlated ≥ |r| = 0.6 o Caught Salmon excluded and total caught fish consumption offered  •  Inclusion of categorical variables that had a p-value ≤ 0.3 following t-tests or ANOVA with blood-mercury concentration  •  Inclusion of continuous variables that had a p-value ≤ 0.3 following simple linear regression with blood-mercury concentration  •  Exclusion of consumed fish species that were negatively associated with blood-mercury concentration following simple linear regression, i.e. a negative coefficient o A negative association could be a surrogate for an unidentified variable o Excluded: bought herring, caught steelhead trout, bought other canned tuna and caught albacore tuna  •  Inclusion of a priori variables that did not meet the aforementioned statistical criteria o Included: sex and bought canned albacore tuna  3.7.3 Multiple Linear Regression Model 
 By combining the recreationally caught and commercially bought variables into one model, all factors affecting blood-mercury concentrations among Vancouver Island recreational anglers could be examined simultaneously. Variables were removed in a backwards step-wise manner, starting with the variables with the highest p-value until all remaining variables were significant to p < 0.05. For the categorical variables, a ‘Western’ ethnicity was the reference variable for  65
  both ‘Estimated Ethnicity 1’ and ‘Estimated Ethnicity 2’. The reference variable for ‘Annual Income’ was the range of ‘$20,000 - $39,999’. The final model is presented in Table 2311. Table 23. Final multiple regression model for the dependent variable blood-mercury concentration (µg/L) and the independent variables caught rockfish, shellfish and cutthroat trout as well as bought other tuna, albacore tuna, snapper, and Estimated Ethnicity 1. N* Model  Coefficient  Standard Error  195 7.2 x 10  Caught Rockfish (g/week) #  Caught Shellfish (g/week) Caught Cutthroat Trout (g/week) +  ^  Bought Other Tuna (g/week) ^  Bought Albacore Tuna (g/week)  195 195 195 195 195  Bought Snapper (g/week)  195  Estimated Ethnicity 1  195  Other  <0.0001 -1  Intercept  20  P-value  -3  3.3 x 10  -4  6.9 x 10  -3  3.6 x 10  -3  3.2 x 10  -3  2.8 x 10  -3  4.4 x 10  -2  <0.0001  -3  0.005  -4  0.031  -3  0.047  -3  0.004  -4  0.001  -3  0.008  9.5 x 10 1.2 x 10 3.2 x 10 1.8 x 10 1.1 x 10 8.0 x 10 1.6 x 10  0.024 1.9 x 10-1  8.4 x 10-2  0.024  α = 0.05 Adjusted R2 = 18.9% * Number of observations # Shellfish includes shrimp, prawns, crabs, mussels, oysters and clams + ‘Other’ refers to species that are not albacore, i.e. skipjack, yellowfin, ahi, etc. ^ Fresh or frozen Note: Western Ethnicity is the reference value, included in the intercept (β0)  From the final model that explained 18.9% of the variability, caught rockfish, caught shellfish, caught cutthroat trout, bought other tuna, bought albacore tuna, bought snapper and Estimated Ethnicity 1 were the predictors of mercury exposure among Vancouver Island recreational anglers.  Within the Estimated Ethnicity 1 variable, a ‘Western’ ethnicity was statistically  different from an ‘Other’ ethnicity. The prediction equation from this model was:  























































 11 The initial model is available in Appendix F (Table 27). 66
  Predicted [blood-mercury] in µg/L = ePredicted ln [blood-mercury] = e0.72 + (3.3E-3 x Caught Rockfish) + (6.9E-4 x  Caught Shellfish) + (3.6E-3 x Caught Cutthroat Trout) + (3.2E-3 x Bought Other Tuna) + (2.8E-3 x Bought Albacore Tuna) + (4.4E-3 x Bought Snapper) + (1.9E-1 x Other Ethnicity)  It should be noted that in an attempt to account for tissue-mercury levels in fish species, as well as to improve the variability of the model, we tried to incorporate species-specific tissue-mercury levels into each of the caught and bought fish species. However, this had no effect on the model since the reported consumption of each species was simply scaled by that species’ tissuemercury level.  Therefore, while the coefficient changed, the relationship between the  consumption of each species and blood-mercury did not.  67
  4. Discussion 
 Between June and November 2010, telephone questionnaires were conducted and blood samples were collected to assess the state of mercury exposure among Vancouver Island recreational anglers. In particular, this study set out to answer the following research questions: 1. Among Vancouver Island recreational anglers, how much of the fish they eat is caught vs. bought? 2. What fish species are Vancouver Island anglers catching and eating? 3. What fish species are Vancouver Island anglers buying and eating? 4. How often are the anglers eating both recreationally caught and commercially bought fish? 5. How does blood-mercury level vary in anglers with respect to varying consumption of commercially bought and recreationally caught fish? 6. What are the differences in blood-mercury levels when considering demographic factors such as angler age, sex, ethnicity and income? As will be discussed in the following sections, the answers to these questions will not only contribute to the literature surrounding this subject area but will hopefully aid the policy makers tasked with developing fish consumption advice.  4.1 Study Population 
 A total of 195 anglers were included in the study. The ‘typical’ study participant was male, born in Canada (parents also born in Canada), 55 years old, 83.6 kg, lived in the central region of Vancouver Island and earned $20,000 - $39,999. Further, 61% held both a BC freshwater fishing license and a federal saltwater fishing license, which demonstrated that even though recruitment was from a freshwater fishing license list, marine fishing habits were captured well. But was the study population representative of the angling population on Vancouver Island? This was particularly important since any resulting policy actions directed toward all Vancouver Island recreational anglers are only applicable if a representative study population was evaluated.  68
  Without a demographic breakdown of the licensing list, it was difficult to accurately determine how well the study population reflected Vancouver Island anglers. However, when comparing to BC anglers as a whole, the study population compared very well with a male to female ratio of approximately 80:20. With respect to age, the study population was slightly older (as illustrated in Table 10). This may be because it was easier for retired people to participate or because of the demographics of those living on Vancouver Island. As reported by O’Neil (2007), Vancouver Island is home to the largest portion of seniors in BC, indicating that while the study population was older, there was representation from across BC age groups. Comparing income between the study population and all BC anglers was difficult because the only income estimate available for all BC recreational anglers was of total household income while the study inquired about personal income. A simple comparison shows that the study population earned less than anglers from all of BC (GSGislason & Associates Ltd. et al., 2009), however the inherent differences between personal and household incomes does not provide enough information to adequately evaluate the study population based on income. Further, comparing angler ethnicities between the study population and the rest of BC was not possible, primarily because there was no information available pertaining to this demographic characteristic.  Regardless, given that  approximately 90% of the study population was born in Canada, it was likely that our population was not overly representative in terms of ethnicity. Not having access to the BC recreational fishing license list was an inherent limitation of this study. However, by comparing the study population to BC anglers as a whole, it appears we captured a representative study population, especially with respect to angler age and sex.  4.2 Fish Consumption and Exposure to Mercury 
 The primary purpose of this study was to evaluate the fish consumption patterns that contribute to mercury exposure, with a specific focus on the consumption of recreationally caught and commercially bought fish. This study was unique in that it attempted to determine differences in exposure from recreational and commercial sources of fish on a species-specific basis. The majority of the studies in this area focus on recreational consumption only.  Further, the  Canadian studies examining recreational fish consumption and mercury exposure have generally  69
  been conducted in Ontario and Quebec. To our knowledge, this was the first study of this kind conducted in British Columbia.  4.2.1 Fish Species Included in the Multiple Regression Model 
 A multiple linear regression model (results shown in Table 23) showed that caught rockfish, shellfish and cutthroat trout as well as bought albacore tuna, other tuna and snapper were independent predictors of exposure to mercury. In terms of whether commercial or recreational fish was the greatest contributor of exposure, three of the predictors were commercial fish species while three were recreational. There was no single specific source of fish, recreational or commercial, that was dominantly predictive. This was further reflected in total consumption frequencies as equal amounts of caught and bought fish were consumed per week. The fact that there was not a clear division between these two fish sources could be because anglers were purchasing and catching the same species, which all originates from the same fishing grounds. Had this study been conducted in the BC interior, i.e. away from the ocean, the contribution of mercury from these sources might have been clearer. However the question then may shift to differences in exposure between salt and freshwater fish, especially since five of the six species that were predictors of exposure were marine species, while the sixth, cutthroat trout, was anadromous. The adjusted R2 value of the model was 18.9%. This compared well to a similar study conducted by Lincoln et al. (2011) who developed a final model with an adjusted R2 value of 17% but was less than the model developed by Kosatsky et al. (2000) who had an unadjusted R2 of 39%12. Bought albacore tuna (fresh/frozen) was the strongest predictor of exposure while bought other tuna (fresh/frozen), which included any species of tuna that was not albacore, i.e. ahi, skipjack and yellowfin, was the second strongest predictor of exposure. These species likely remained in the final model because of the amount consumed as well as the tissue-mercury levels found in tuna. First, while only 12% of the population consumed bought albacore tuna, those that did, ate it frequently (99 g/week). For perspective, one portion size was equivalent to 75 g and Kosatsky 























































 12 Kosatsky et al. (2000) expressed consumption frequencies as categorical variables, which increased the number of variables in the model and likely increased the R2 value. 70
  et al. (2000) defined frequent fish consumption as one meal of fish per week. At 17%, slightly more subjects consumed bought other tuna and ate almost one portion per week on average (69 g/week). This higher consumption among tuna consumers was one of the reasons why both bought albacore and other tuna remained in the model.  Another reason was the higher  concentrations of mercury typically found in the tissue of these species. For example, the CFIA has reported a mean tissue-mercury level of 0.28 µg/g in albacore, 0.57 µg/g in ahi, 0.10 µg/g in skipjack and 0.44 µg/g in yellowfin. The effect of eating tuna on mercury burden is relatively well known, as evidenced by the Seychelles pilot study conducted by Matthews (1983) as well as Hightower and Moore’s (2003) study that found a blood-mercury level as high as 18 µg/L in a woman who consumed ahi tuna steaks. The elevated risk of exposure is why Health Canada has developed a separate fish consumption guideline designed to limit the consumption of these species (Health Canada, 2008). Based on the amount of tuna consumed and the concentration of mercury found in tuna tissue, it was expected to see these fish species as independent predictors of exposure. The combination of higher tissue-mercury levels and consumption frequency was also the reason why caught rockfish remained in the final model. While only 24% of the population reported eating rockfish, those that did consumed it frequently (71 g/week on average). Combined with the moderate amount of mercury the CFIA has found in rockfish (0.23 µg/g), it was not surprising to see this species as a predictor of exposure. Lincoln et al. (2011), who conducted a study similar to ours, concluded that the frequent consumption of fish species containing moderate amounts of mercury has a greater effect on exposure than the infrequent consumption of species containing high amounts of mercury. This appeared to be the case in our study as well given the amount of bought tuna and caught rockfish consumed per week and the concentrations of mercury found in these fish species. Rockfish are carnivorous, have a long lifespan and grow slowly, characteristics that cause them to accumulate higher levels of mercury (Debruyn et al., 2006). Interestingly, Debruyn et al. (2006) found an increase in mercury levels in rockfish prey in areas around net-pen salmon farms near Alert Bay, BC and Ahousaht, BC (both on Vancouver Island). This was as a result of salmon feed that contained mercury and from the creation of anoxic conditions, both of which  71
  increased the formation of methylmercury.  Debruyn et al. (2006) estimated that these  conditions, along with the predatory nature of rockfish, resulted in an estimated 1.4 - 2.2 fold increase in tissue-mercury concentrations within the rockfish feeding in these areas. However, the absolute effect on tissue-mercury levels were variable as rockfish caught around Ahousaht, BC contained between 0.11 µg/g and 0.43 µg/g of mercury while those caught near Alert Bay, BC contained between 0.04 µg/g and 0.12 µg/g of mercury (Debruyn et al., 2006). Besides salmon farms, other possible sources of mercury include pulp and paper mills, such as those near Crofton, BC and Nanaimo, BC and a former chlor-alkali plant in Squamish, BC. While the exact location of where each subject caught their rockfish was unknown, this does provide some information as to why mercury levels were elevated in rockfish, especially around Vancouver Island, and is particularly concerning because it takes years for mercury to decline in both sediment and fish tissue (Debruyn et al., 2006). Bought snapper was another fish species that was found to be an independent predictor of mercury exposure.  Compared to bought tuna and caught rockfish, more people reported  consuming this species (27%). At an average consumption of 52 g/week, it was not eaten as frequently as other species that were predictors of exposure. The CFIA has limited mercury information regarding snapper but in the six samples they have taken, as little as 0.07 µg/g has been found in mangrove snapper and up to 0.25 µg/g in red snapper. While it is possible that the moderate consumption of snapper coupled with these tissue-mercury levels explained why bought snapper was a predictor of exposure, there was also the possibility that snapper remained in the model because it was misclassified as rockfish. Rockfish is also known as pacific snapper (Jacquet & Pauly, 2007) and it was possible that subjects who ate rockfish identified it as snapper on the questionnaire. This problem outlines the inherent difficulties in fish recall, especially on the commercial side where identification relies on the label facing the buyer. For example, Marko et al. (2004) found that of 22 ‘red snapper’ tissue samples taken from nine retailers in eight U.S. states, 17 were entirely different fish species. In addition, Hightower and Moore (2003) found a significant and negative correlation between snapper consumption and blood-mercury concentration. They attributed this to the uncertainty surrounding tissue-mercury concentrations in commercial snapper as well as the mislabeling of this species (Hightower & Moore, 2003). Given the popularity of rockfish on Vancouver Island and the challenges of  72
  proper species identification, it was possible that bought snapper was not a true predictor of exposure. The other species that were independent predictors of mercury exposure were caught cutthroat trout and caught shellfish. Both of these were unexpected to be in the final model given the lower mercury content of both species. Shellfish included a variety of species including clams, oysters, mussels, shrimp, prawn, scallops and crabs. They were grouped into one category because they all typically contain low amounts of mercury and it would have lengthened the questionnaire to list every single type of shellfish. The CFIA does have tissue-mercury data on these species, the vast majority of which contain around 0.05 µg/g of mercury. In a survey of commercial fish species in New Jersey, Burger et al. (2005) found tissue-mercury concentrations in shrimp and scallops as low as 0.01 µg/g. It was possible that despite lower tissue-mercury concentrations, caught shellfish remained in the model because 61% of the study population reported consuming it in relatively high frequencies (110 g/week on average). It should be noted that portion size estimates for shellfish were likely misclassified since subjects were asked to provide a single portion size estimating both shellfish and finfish consumption. Regardless, this overestimation would only have affected the coefficient and not the presence of shellfish in the model. Another explanation as to why shellfish remained in the model could be higher tissue-mercury levels found in crab. While smaller shellfish have mercury levels that are quite low, higher concentrations in crab have been found in other studies. For example, Sunderland (2007) found a mean tissue-mercury concentration of 0.15 µg/g in crab caught from the Pacific Ocean and 0.26 µg/g in crab caught from the Atlantic Ocean while Lincoln et al. (2011) used an estimate of 0.18 µg/g for crab caught in the Gulf of Mexico. Differences in mercury concentration not only exist between geographic locations but also between crab species. The most recent CFIA data has found average tissue-mercury levels of 0.06 µg/g in Dungeness crab, 0.07 µg/g in Rock crab, 0.09 µg/g in Snow crab and 0.52 µg/g in Red crab13. However, the limitation of CFIA data is that it is not region-specific, i.e. tissue-mercury averages are compiled from across Canada. Because of the geographic and species variability observed in crab, it is possible that crab on 























































 13 Only three Red crab tissue samples were collected by the CFIA. 73
  Vancouver Island contain higher mercury levels. When consumed in the quantities observed in this study, the presence of shellfish in the final model may not be as unexpected. An extensive survey of shellfish around Vancouver Island would help to determine whether there are regionspecific differences in tissue-mercury concentrations that would help to explain why shellfish remained in the final regression model. Separating crab from other types of shellfish on future questionnaires would also help to determine whether crab, and not shellfish consumption as a whole, is a predictor of exposure. The CFIA does not have a specific tissue estimate for cutthroat trout. However, they do provide an average general trout estimate of 0.09 µg/g. Dabeka et al. (2004), who conducted a survey of Canadian commercial fish species, determined an average concentration of 0.04 µg/g for unspecified trout species. Cutthroat trout consumption was reported by 22% of the population and was eaten moderately at an average of 55 g/week. While consumption patterns were similar to those seen with bought snapper (also a predictor of exposure), lower reported tissue-mercury levels makes the presence of cutthroat trout in the final model slightly puzzling. This was compounded by the fact that rainbow trout, a species very similar to cutthroat trout, was consumed more frequently but was not a predictor of exposure. Rainbow trout typically exist in the same waters as cutthroat trout and in greater abundance (Nilsson & Northcote, 1981). Within British Columbia, Rieberger (1992) surveyed heavy metal concentrations in salmonid species throughout 54 BC lakes, including a handful on Vancouver Island. Cutthroat trout had the highest average tissue-mercury concentration at 0.29 µg/g while rainbow trout samples had an average concentration of 0.09 µg/g. The highest tissue-mercury level found in cutthroat trout on Vancouver Island was found in Flume Lake (0.25 µg/g) while the highest totals overall were found in lakes on the Queen Charlotte Islands (up to 0.64 µg/g). At these concentrations, it is surprising that the CFIA does not have a tissue-mercury estimate for cutthroat trout (likely due to their focus on commercial fish species) and that neither the BC government nor Health Canada make consumption recommendations for this species. Even though rainbow and cutthroat trout are similar fish species and inhabit many of the same lakes and rivers, Nilsson and Northcote (1981) found that cutthroat trout tend to eat 1) more fish and 2) larger fish, possibly due to slight physiological differences such as a larger mouth.  Deniseger et al. (1990) also noted this  difference in tissue-mercury content among similar fish species that inhabit the same lakes and  74
  concluded that tissue results of rainbow trout cannot be generalized to other salmonid species. These differences may explain why cutthroat trout was a predictor of exposure while rainbow trout was not. Adding to this inter-species variability is the notion of inter-lake mercury variability. Moran et al. (2007) collected tissue samples of various trout species from 14 lakes in the Olympic, Mt. Rainer and North Cascades National parks in Washington State and analyzed them for mercury. One lake contained trout with tissue levels of 0.10 µg/g while another contained trout with concentrations of 0.26 µg/g. This suggests great lake-to-lake variability in mercury content within fish and raises the possibility of such levels on Vancouver Island. Given that cutthroat trout was determined to be a predictor of exposure and there is the possibility of regional differences in tissue-mercury concentrations, monitoring efforts should focus on this species. Further, because cutthroat trout are anadromous, surveys should sample fish in both fresh and saltwater. Overall, the lack of current tissue-mercury levels in cutthroat trout makes it difficult to conclude with certainty that this fish species is a true predictor of exposure. Past data suggests mercury levels in cutthroat trout may be high but this can only be confirmed with new samples from this region. In turn, this information would help the BC government determine whether consumption guidelines need to be expanded to include cutthroat trout. In general, the fish remaining in the final regression model were predatory species that contained elevated tissue-mercury concentrations. Even though the species identified in our study were not the focus of other studies, this trend has held true throughout the literature. For example, Kosatsky et al. (2000) found that consuming pike (tissue-mercury levels between 0.32 µg/g and 1.04 µg/g) ≥ 1/week was the greatest independent predictor of exposure in their angling cohort while Johnsson et al. (2004) found that pike and perch consumption (tissue-mercury level between 0.60 µg/g and 0.70 µg/g) were the cause of elevated hair-mercury levels in their study population. Overall, our results support the findings of other studies that frequent consumption of fish containing moderate amounts of mercury can have substantial effects on mercury exposure (Lincoln et al., 2011).  75
  4.2.2 Fish Species Not Included in the Final Multiple Regression Model 
 While it was not unexpected to see tuna and rockfish included in the final model, it was surprising not to see other species that contain elevated levels of mercury such as halibut, sablefish, and canned albacore tuna. The CFIA has found average tissue-mercury concentrations > 0.25 µg/g in both sablefish and halibut. Despite this mercury level, the removal of sablefish from the model could be attributed to the fact that only 11% of the population ate this species and did so in lower frequencies (34 g/week on average). However, nearly two-thirds of the subjects reported eating bought halibut at an average frequency of 60 g/week and 40% reported eating caught halibut at an average frequency of 78 g/week. With the number of anglers eating these fish species at relatively high frequencies, it was surprising to not see either type of halibut remain in the model. It could be possible that the halibut consumed were simply younger and smaller, therefore containing less mercury (Burger and Gochfeld, 2007). For example, while the CFIA has found average tissue-mercury levels of 0.26 µg/g in Pacific halibut, values as low as 0.05 µg/g have been recorded. Even with greater consumption among the population, lower tissue-mercury levels could have caused both caught and bought halibut to be removed from the model. Canned tuna was another commercial product that was expected to be an independent predictor of exposure, particularly canned albacore tuna, i.e. ‘white’ tuna. Burger and Gochfeld (2004) sampled 123 cans of canned albacore tuna and found a mean mercury concentration of 0.41 µg/g. They also sampled 45 cans of ‘light’ tuna, i.e. other canned tuna, and found a mean mercury concentration of 0.12 µg/g. These results were similar to those found by the CFIA where canned albacore tuna averaged 0.40 µg/g while canned “light” tuna averaged 0.18 µg/g. However, consumers of canned albacore (36%) and canned other tuna (38%) ate approximately one standard can (~120 g) per week, which is in accordance with BC consumption guideline advice (HealthLink BC, 2011), and may explain why canned tuna was not a predictor of exposure. Another reason why canned tuna did not remain in the model was that, since subjects were reporting one average portion size for all fish species, consumption might have been misclassified, making associations more difficult to detect. Further, some subjects had difficulty differentiating between the two types of tuna and were often unsure of the specific species. If  76
  subjects identified ‘light’ tuna as canned albacore, the mercury contribution from canned albacore would have been diminished. Caught fresh/frozen albacore tuna was also expected to be a predictor of exposure, particularly because it was a predatory fish species and because the mean CFIA tissue-mercury estimate for albacore was 0.28 µg/g. However, even though consumers of caught albacore ate an average of 200 g/week, only 5.6% of the population reported any consumption. It was possible that there were simply too few observations for a relationship with blood-mercury to be accurately determined, which could explain why a negative association with blood-mercury was observed in simple linear regression. Because of this negative relationship, caught albacore tuna was not offered to the multiple regression model. Another possibility for this negative relationship was that caught albacore tuna acted as a surrogate for another unmeasured variable.  A final  explanation for why caught albacore was not found to be a predictor of exposure could be that Pacific-caught albacore contains lower concentrations of mercury.  As Sunderland (2007)  discovered, compared to albacore caught in the Atlantic Ocean (mean tissue-mercury of 0.47 µg/g) and Mediterranean (mean of 0.87 µg/g), those caught in the Pacific Ocean contained the lowest mercury concentrations (mean of 0.17 µg/g). This has been reflected in British Columbia consumption advice as HealthLink BC has removed consumption limits on albacore tuna that is caught in BC or Canada (HealthLink BC, 2011). This advice also extends to canned albacore tuna caught in BC or Canada, which is significant considering the popularity of canned tuna and the health benefits associated with eating fish. A final species that was expected to be a predictor of exposure was caught lingcod. Not only does this species have a higher tissue-mercury as determined by the CFIA (0.19 µg/g), but it was also consumed in similar quantities as rockfish. Further, it had the highest adjusted R2 value in simple linear regression among all fish species. One possibility was the correlation between caught lingcod and caught rockfish. At r = 0.59, this pair was just below the cutoff of r = 0.60 for inclusion into the multiple regression model. As such, there was the chance that the presence of caught rockfish was sufficiently correlated with lingcod to cause the removal of lingcod from the model. Given their correlation, it is reasonable to interpret the rockfish in the model as in part representing the effect of lingcod.  77
  Interestingly, the variables ‘Total Caught Fish Consumption’ and ‘Total Bought Fish Consumption’ did not remain in the final model. Both of these were expected to remain given they represented an overall estimate of consumption. ‘Total Caught Fish Consumption’ was significantly, and positively, associated with blood-mercury in bivariate analyses but was not retained in the final multivariate model. This may have been because of the close correlation with caught salmon, which typically contains minimal amounts of mercury. ‘Total Bought Fish Consumption’ was not significantly associated with blood-mercury in either simple or multiple regression models.  This result was consistent with Gobeille et al. (2006) who found no  association between commercial fish consumption and blood-mercury levels, even though 82% of their study population reported consuming commercial fish species. In our study, this may have occurred because the few fish species that were predictors of exposure made up only a small fraction of total bought fish consumption. Salmon, rainbow trout and sole were not found to be predictive, as was expected. Salmon was the most frequently consumed fish species from both caught and bought sources. However, tissue-mercury levels are so low in these species that it would not be expected to remain in the final model, regardless of the quantity consumed. Caught rainbow trout was another commonly consumed species however it was not offered to the final regression model because consumption was not associated with blood-mercury at a p-value ≤ 0.3 in simple linear regression. This was likely a result of low tissue-mercury levels as well. Bought rainbow trout was offered to the model but was not eaten as frequently as caught rainbow trout or salmon. Coupled with low tissue-mercury concentrations, bought rainbow trout was not expected to be a predictor of exposure. Lower tissue-mercury concentration was the likely reason why bought sole also did not remain in the final model. These results strengthen the validity of the model and supports provincial and federal fish consumption guidelines pertaining to these species.  4.2.3 Relevance of Blood-Mercury Concentrations 
 While certain fish species were predictors of blood-mercury concentrations, it was important to place the blood results into perspective. The geometric mean blood-mercury concentration was 2.33 µg/L, which was greater than the geometric mean found in the Canadian population (0.69  78
  µg/L) as well as the 75th percentile (1.61 µg/L) (Health Canada, 2010), and suggests that anglers have greater exposure to mercury by virtue of their fish consumption patterns than does the general public. This may have been expected since the CHMS considers the entire Canadian population, many of whom are not fish consumers, while 100% of our study population ate fish. However, 95% of the Canadian population has a blood-mercury level ≤ 4.70 µg/L (Health Canada, 2010), indicating that while Vancouver Island anglers have higher exposures, mean blood-mercury levels do not fall outside of the 95th percentile. Further, none of the bloodmercury levels observed in the study population surpassed the Health Canada blood-mercury guideline of 20 µg/L for men > 18 years old and women ≤ 50 years old and 8 µg/L for men ≤ 18 years old and women < 50 years old (Legrand et al., 2010). Our blood-mercury results were slightly lower than those found by other studies but compared well. Among frequent fish consumers, Quebec recreational anglers had a geometric mean bloodmercury of 3.03 µg/L (Kosatsky et al., 2000) while a study examining Ontario anglers found a geometric mean blood-mercury of 2.20 µg/L (Cole et al., 2004). Further, in a study examining exposures among 104 anglers who consumed fish from the Hudson River, Gobeille et al. (2006) discovered a mean blood-mercury concentration of 2.40 µg/L. While we did not measure hairmercury levels, other studies that used hair as a biomarker also found levels well below the Health Canada hair-mercury guideline of 6 µg/g. For example, recreational Louisiana anglers had a median hair-mercury level of 0.81 µg/g (Lincoln et al., 2011) while the median level in a cohort of Swedish anglers was 0.90 µg/g (Johnsson et al., 2004). Converting these values to blood-mercury (3.24 µg/L and 3.60 µg/L respectively), they were slightly higher than the levels we found, which may reflect region-specific differences in fish tissue mercury concentrations and fish consumption habits. While six fish species were predictors of blood-mercury levels, the observed blood-mercury concentrations were not overly high.  This was encouraging given the quantities of fish  consumed by Vancouver Island anglers. These lower mercury levels were likely the result of frequent consumption of fish species lower in mercury such as salmon and rainbow trout. However, we should not downplay the potential for mercury exposure, especially since “the no effect level for [methylmercury] has not been established” (Knobeloch et al., 2007, p. 206).  79
  Three subjects had a blood-mercury level > 10 µg/L.  These subjects reported frequent  consumption of bought other tuna, caught rockfish, bought albacore tuna and/or caught halibut. Without any other sources of mercury exposure, it was evident that frequent consumption of fish species containing moderate amounts of mercury can have a profound effect on blood-mercury, a conclusion also made by Lincoln et al. (2011). This is evident through the prediction equation derived from the multiple regression model. If the mean weekly consumption for those who consumed caught rockfish, shellfish and cutthroat trout (Table 17) and bought albacore tuna, other tuna and snapper (Table 19) were entered into the prediction equation derived from the multiple regression model, an angler born in Canada would have a blood-mercury level of 7.06 µg/L. For an angler not born in Canada, this would increase to 8.54 µg/L. These values would be greater than the 90th percentile of blood-mercury concentrations found in our study, which investigated a population already at risk of exposure.  4.3 The Effect of Angler Age, Sex, Ethnicity and Income on Mercury Exposure 
 Angler age is a demographic factor that has been suggested to be a determinant of mercury exposure, primarily as a result of increased fish consumption. While an increasing trend in blood-mercury was observed with age in bivariate analysis, the relationship was not significant. Age was also removed in the multiple regression analysis. However, age has been found to remain significant in other studies and attributed to an increase in the frequency of fish consumption (Kosatsky et al. 2000; Mahaffey & Mergler, 1998; Rhainds et al, 1999). Simple linear regression conducted in this study between total caught fish consumed and age, as well as between total bought fish consumed and age demonstrated a slight increase in consumption with age, albeit not statistically significant. Perhaps the fact that over 50% of the population was older than 55 years of age did not provide enough variability within the population to determine a clear relationship. Angler gender is another demographic variable shown to be a predictor of mercury exposure. Males tend to have greater exposure to mercury than females because they consume greater amounts of fish (Johnsson et al., 2004; Mahaffey & Mergler, 1998; Knobeloch et al., 2007) and because females reduce their overall mercury body burden through pregnancy and breastfeeding  80
  (Cole et al., 2004). Similar to other studies, men in our study had higher blood-mercury levels than women, although this relationship was not significant. Further, angler gender did not remain in the multiple regression model. As opposed to other studies, females in our study consumed significantly more total caught fish than men (Table 12). However, men did consume more bought fish, although this difference was not significant (Table 13). Both Knobeloch et al. (2007) and Johnsson et al.’s (2004) studies, conducted in Wisconsin and Sweden respectively, attributed greater exposure in men to larger portion sizes, as well as to the consumption of fish species containing moderate amounts of mercury such as pike and perch (Johnsson et al., 2004). In our study, women may have consumed more recreational fish, but ate species lower in mercury. For example, they consumed significantly more caught salmon (330 g/week) and rainbow trout (58 g/week) than men (160 g/week and 28 g/week respectively). This could be one explanation as to why women consumed more caught fish but had lower blood-mercury levels. With respect to reproductive events that may have contributed to women having lower blood-mercury concentrations, we did not ask women if they were pregnant or had recently given birth and therefore cannot make any definitive conclusions pertaining to this possibility. Finally, it has been suggested that differences in the metabolism of methylmercury might be an explanation as to why men typically have greater mercury levels compared to women (Knobeloch et al., 2007). However, this theory is not widely accepted as there is evidence suggesting that the elimination of mercury is actually slower in females, resulting in a greater body burden (Nielsen & Andersen, 1996). Angler ethnicity is another demographic variable shown to predict mercury exposure, a result of certain cultures consuming fish more frequently as well as eating species that contain higher amounts of mercury (Knobeloch et al, 2005; Cole et al., 2004; McKelvey et al., 2007). Therefore, it is not ethnicity per se that determines exposure as much as it is a diet type. In the final model, ‘Estimated Ethnicity 1’ remained statistically significant while ‘Estimated Ethnicity 2’ did not. The former defined ethnicity based only on the subject’s country of birth while the latter relied on a mix of both the subject’s and subject’s parents’ countries of birth. It was hypothesized that determining the country of birth would reflect a more accurate diet type as opposed to asking for each subject’s ethnicity. As presented in Tables 12 and 13, there were no significant differences in the amount of total caught or total bought fish consumed between a  81
  ‘Western’ and ‘Other’ ethnicity for Estimated Ethnicity 1. However, ‘Estimated Ethnicity 1’ remained significant in the model, which may be a result of the specific fish species consumed. Among consumers, those of an ‘Other’ ethnicity consumed significantly more bought sardine and bought lingcod. The CFIA has shown lingcod to contain a moderate amount of mercury (average of 0.19 µg/g) while sardine has been shown to contain an average of 0.05 µg/g. It is possible that this extra consumption of lingcod was the reason why ‘Estimated Ethnicity 1’ remained in the final model. However, even though ethnicity remained in the model, it would be difficult to definitively conclude that there were differences in exposure based on the subjects’ country of birth when approximately 90% of the study population was born in Canada. Annual income was the final demographic variable that has been hypothesized to have an effect on blood-mercury. Hightower and Moore (2003) suggested an increase in exposure with income because subjects consumed more expensive fish species that contained higher amounts of mercury, such as swordfish and ahi tuna. In simple linear regression, anglers in the < $20,000 income bracket consumed significantly more total caught fish than those in the $60,000 $79,999 category. There was no significant difference in blood-mercury, likely because of the high correlation between caught salmon (low mercury level) and total caught consumption. It should also be noted that while the variable as a whole was not significant following multiple regression, throughout the stepwise removal of variables, the category of > $80,000 was always significantly different (positively) than the reference category of $20,000 - $39,999.  One  possibility for this was the consumption of bought other tuna. 6.7% of the study population earned > $80,000/year and ate bought other tuna. They had an average consumption frequency of 100 g/week for this fish species. 4.1% of the population were in the income category of $20,000 - $39,999 and ate bought other tuna, yet they only consumed an average of 28 g/week. While the number of observations was low in both income categories, the difference in consumption of bought other tuna, which is typically higher in mercury, may explain this observation.  82
  4.4 Other Potential Sources of Exposure 
 Occupational exposure to mercury was the primary other variable that could have influenced blood-mercury results. There were only six subjects who reported current work in any of the occupational locations of concern. With the exception of one subject, the blood-mercury levels were well below the typical levels found in 95% of the Canadian population (4.70 µg/L). The one subject who had a blood-mercury concentration greater than this value (7.40 µg/L) reported working in three of the concerning workplaces as a contracted electrician in the past year, one of which was a chlor-alkali plant.  According to the ATSDR, average blood-mercury levels  between 10 µg/L and 19.9 µg/L have been found in chlor-alkali plant workers (ATSDR, 1999). Given this information, it would be difficult to definitively conclude that this subject’s bloodmercury level was a result of occupational exposure. There were nine subjects who reported some form of past exposure to mercury, one of whom had a blood-mercury concentration of 6.70 µg/L. This individual reported residing in a gold mining camp as a child and had undergone mercury chelation therapy following the removal of eight dental amalgams all at once, 10 years prior to this study. The presence of a large number of dental fillings (> 8) has been shown to be a significant source of mercury exposure with up to 120 µg of elemental mercury potentially being released into the mouth per day, some of which may be inhaled or swallowed (Lorscheider et al., 1985). In a review of seven Swedish studies, Weiner and Nylander (1995) estimated a mean elemental mercury uptake of 4 - 19 µg/day due to general wear on dental amalgams, i.e. brushing, teeth grinding, drinking hot beverages, etc. While it is possible that this subject’s elevated blood level was a result of these exposures, given that the half-life of methylmercury is approximately 50 days (Stern, 1993) and the amalgams were removed 10 years ago, it would be unlikely. Another subject reported working in a pulp and paper mill for 25 years and had a blood-mercury level of 7.00 µg/L. He now owns a sport fishing business and consumes 450 g of caught fish per week including 230 g of caught rockfish and 110 g of caught lingcod. While it is possible that his blood-mercury level is a result of his previous employment, it is more likely that the primary source of exposure is now from the fish that he eats.  83
  Overall, few of the subjects had other mercury exposures that were likely to influence bloodmercury concentrations. As such, we are confident that the blood-mercury levels observed in our study were attributable to exposure from fish consumption.  4.5 Potential Policy Developments 
 There are a number of policy developments from this study that could be applied to reducing exposure and benefiting angler health.  First and foremost are reexamining public fish  consumption guidelines. From the results of the multiple regression model, caught rockfish, shellfish and cutthroat trout as well as bought albacore tuna, other tuna and snapper were the six species that were independent predictors of exposure. Health Canada and the BC government do a reasonable job of publishing information for the general public. Both have consumption limits for tuna and the BC government even differentiates between consumption frequencies for domestic and imported albacore tuna (HealthLink BC, 2011). The BC government considers rockfish to be a species that should be consumed in moderation. However, Health Canada does not offer any consumption advice with respect to this species (Health Canada, 2008). Given that it was found to be a predictor of exposure, further investigation should be conducted into mercury levels in rockfish, particularly since 18,100 tonnes were harvested in BC in 2009 for a wholesale value of $37.2 million (BC Ministry of Agriculture, 2011). While consumption of cutthroat trout was much lower in our study, it is a species widely consumed by recreational fishers. In 2005, 62,030 cutthroat trout were caught and kept on Vancouver Island, which was the most kept freshwater species ahead of rainbow trout (56,810) and salmon (14,280) (GSGislason & Associates, Ltd. et al., 2009). In this study, cutthroat trout was not the most commonly consumed species, however almost a quarter of the study population (22%) reported catching and eating it, which was comparable to the percentage of the population who ate caught rockfish and lingcod. This warrants further study into mercury levels in cutthroat trout not only because it was an independent predictor of exposure, but also because there is little up-to-date information in the literature regarding mercury concentrations in this species. Finally, tissue-mercury levels in shellfish (especially crab) should be investigated further. Mercury concentrations in crab have been shown to vary geographically as well as between species.  84
  HealthLink BC (2011) currently has no consumption recommendations for crab while Health Canada (2008) promotes the consumption of blue crab as well as shrimp, clams, mussels and oysters. The CFIA mercury estimates for crab vary depending on species. Considering the popularity of crab on Vancouver Island and the various species available, gathering regionspecific information on mercury levels in crab (particularly near past and present industrial sites) would  help  federal  and  provincial  governments  determine  whether  consumption  recommendations are warranted. Perhaps the greatest policy implication from this study is the recognition that region-specific fish monitoring is extremely important for developing relevant consumption advice. While this is frequently done for recreational fish, this study suggests that region-specific monitoring of purchased fish may be just as important. This is of particular significance in British Columbia where there is substantial access to locally originating fresh and saltwater fish species. For recreational species, information on cutthroat trout should be generated given its popularity (almost a quarter of the population reported some consumption of this species, which was similar to the consumption of rockfish) and its status as a predictor of blood-mercury levels. This is in contrast to monitoring for mercury in smallmouth bass, for example, as only six out of 195 Vancouver Island anglers caught and consumed it. In general, there appears to be a lack of relevant tissue-mercury data for coastal British Columbia. As determined by a consulting report conducted by Aqualibrium Environmental Consulting Inc. (2002) that investigated the state of mercury levels in BC freshwater fish, there has been a number of tissue-mercury surveys performed in BC since 1970. However, only a handful of them have been conducted well, all of which date back over 20 years (Aqualibrium Environmental Consulting Inc., 2002). The main problem has been a lack of consistency between studies including missing fish characteristic data, i.e. age, length and weight, as well as the mixing of dry weight and wet weight measurements when determining tissue-mercury content. These issues are compounded by short-term, convenience sampling strategies and small sample sizes (Aqualibrium Environmental Consulting Inc., 2002). Reliable information on tissue-mercury levels is also lacking in some commercially important species including rockfish, crab, and lingcod. Currently, rockfish is the only one of these species  85
  that the BC government recommends eating in moderation (refer to Table 3). By supplementing the results of this study with up-to-date tissue-mercury concentrations, cutthroat trout, crab and lingcod may need to be added to HealthLink BC’s fish consumption recommendations; and like rockfish, may be species that should be consumed in moderation.  4.6 Study Biases 
 There were a number of potential biases that may have had an effect on the results.  4.6.1 Selection Bias 
 While all efforts were made to recruit a random study population, it was possible that the subjects who decided to participate did so for reasons that made them atypical of the general population. These may have included those who were particularly interested in mercury, i.e. new mothers, or those who had had previous exposure to mercury, such as the subject who had undergone chelation therapy. This could also include a preference for English speaking anglers or those who had time to complete the study. These latter two reasons are possible explanations for why the majority of subjects were born in Canada and were retired. Providing recruitment materials in other languages, especially East Asian languages, may have improved recruitment of these anglers while offering an online questionnaire may have helped to recruit younger participants.  4.6.2 Misidentification of Fish Species 
 The misidentification of fish species may have contributed to a bias in the reporting of the results.  This was most evident when reporting species of canned tuna.  Throughout the  questionnaire, some subjects were unsure of the type of canned tuna they were eating, which could have resulted in the misclassification of the species of tuna consumed. Variability in the weight of different brands of canned tuna may also have contributed to errors in estimating the amount consumed.  86
  The various pseudonyms for fish species were also a challenge for proper species identification. This was most evident when anglers reporting catching rockfish, which is also known as Pacific snapper, and cod, which tended to be used as a generic label when anglers where unsure of what they had caught. However, unlike with the canned tuna, this was less of a problem since it was possible to place these species into their correct categories prior to data analysis. From the bought side of consumption, there was also the possibility that markets and stores misidentified fish species, which would have in turn, mislead the anglers.  4.6.3 Portion Size Recall Bias 
 During the administration of the questionnaire, subjects were asked to provide a portion size estimate. This estimate was meant to represent a typical portion size of both caught and bought fish meals. Forcing the subjects to report one portion size for all consumption likely lead to the overestimation of smaller seafood species, such as shellfish and canned tuna. Misclassification of fish portion size by species likely made it more difficult for certain species to be significant in the model. However, by providing images of fish filets, an accurate estimation of finfish portions was likely attained, which was particularly important given the greater contribution to exposure from finfish consumption.  4.6.4 Difficulties with Dietary Recall 
 Selected recall timeframes were chosen to accurately determine exposure by maximizing dietary recall. With a six-month recall time, it was assumed that subjects would be able to adequately describe their total and individual species fish consumption. However, consumption frequencies appeared to be quite high for each subject. This pattern is not uncommon and was seen in studies that used food frequency questionnaires to examine mercury exposures among Louisiana anglers (Lincoln et al., 2011) and among a high fish-consuming population in Sweden (Bjornberg et al., 2005). As more options are presented on a food frequency questionnaire, i.e. the number of fish species in our study, the greater the chance of over reporting (Krebs-Smith et al., 1995).  In contrast, summarizing a number of consumption options, such as the total  caught/bought fish consumption questions in our questionnaire, results in underreporting  87
  (Serdula et al., 1992). A combination of over reporting the consumption of each individual species and underreporting the total caught/bought consumption may explain why for each subject, the sum of each individual caught/bought species did not equal the total caught/bought fish consumption. As suggested by Lincoln et al. (2011), the actual consumption frequencies of both total and individual fish species may fall somewhere in-between the reported values. Additionally, the misclassification of total caught/bought consumption may explain why total bought fish consumption was not significantly associated with blood-mercury levels in bivariate analysis and why both variables did not remain in the final model. The overall effect of this on the multiple regression model would depend upon the degree of misestimation and whether each species was equally misrepresented. However, these discrepancies in dietary reporting may have contributed to the small proportion of variance explained by the model (adjusted R2 value of 18.9%).  4.7 Study Strengths 
 The greatest strength of this study was that it was the first to evaluate methylmercury exposures among recreational anglers in British Columbia. The majority of Canadian studies examining recreational anglers have been conducted in Ontario and Quebec where the focus has been on freshwater fish species. By examining fishing populations on Vancouver Island, the contribution of saltwater fish species, both caught and bought, was also captured.  4.7.1 Study Design 
 The study was able to capture valuable information on the three main determinants of mercury exposure as a result of eating fish. Throughout the literature, the focus has primarily been placed on fish consumption frequency and the species of fish consumed, with the third determinant of exposure, portion size, typically being left to estimation. By collecting information on portion size, as well as accounting for possible confounders of exposure, a more accurate assessment of exposure was accomplished.  88
  In addition, sampling throughout the summer captured peak recreational fishing activity. This was critical given that both fish consumption and blood-mercury levels tend to be greater in the summer compared to the winter (Johnsson et al., 2004; Kosatsky et al., 2000).  4.7.2 Data Collection 
 Even though the response rate for the study was only 9.4%, the study completion rate was 89.2%. Therefore, while it was difficult to recruit subjects, once they were enrolled, the vast majority completed the study. Given the method of recruitment, retaining such a high proportion of subjects was another strength of the study. Further, we were able to capture an adequate representation of the Vancouver Island fishing population, particularly females. Fishing tends to be a male dominated activity and had we only been able to capture male exposure, the applicability of the results to the Vancouver Island fishing community as a whole would have been lost. Another strength pertaining to data collection included the use of a telephone questionnaire. While a script was strictly adhered to during the interview, subjects were able to ask questions and clarify their responses, which likely resulted in more accurate results. Further, contracting LifeLabs® for the data collection increased the access to blood-collection services throughout the region. There were two instances where a LifeLabs® location was not available. The first was in Port McNeill where one subject had their blood sampled at a local clinic and the second was in Ucluelet where a subject was unwilling to travel to get the blood sample taken. Given the number of rural communities on the island, losing only one subject to a blood sample collection problem was reasonable.  4.8 Study Limitations 
 Aside from the aforementioned study biases, there were other limitations. The largest of these was the inability to access the BC Ministry of Environment freshwater fishing license list. Had we had access to this list, we would have been able to maintain the random sampling strategy while focusing our recruitment on underrepresented segments of the population, especially  89
  anglers who come from non-Canadian ethnic backgrounds. With such a large proportion of anglers who were Canadian, the ability to make effective comparisons among anglers of different ethnicities was lost. This could have been remedied by having access to the list.  4.8.1 Study Design 
 In terms of the questionnaire, asking subjects to provide one average portion size was a limitation when it came to estimating smaller fish species. As stated earlier, this resulted in the misclassification (and likely overestimation) of the consumption of these species. While this decision was made to maintain the attention level of the subjects during the interview by keeping the questionnaire to a reasonable timeframe, it may have introduced some bias into the results of the smaller seafood products. In addition, the questionnaire was based on previously validated questions and was pilot tested prior to use. Even though few questionnaires are fully validated (Nieuwenhuijsen, 2003), it would have been ideal to fully validate the questionnaire. However, this can take a considerable amount of time, as it took Canuel et al. (2006) two years to determine “the consistency of estimated portion sizes and number of fish meals” (Canuel at al., 2006, p. 304) in their study that examined Quebecois and First Nations anglers and would likely require the collection of food diary information from a test population, as was conducted by Shatenstein et al. (1999) in preparation for the main study investigating methylmercury exposures among Quebecois anglers (Kosatsky et al., 2000).  4.8.2 Data Collection 
 While we were able to contact our study population by mail, the response rate was low. With access to the freshwater fishing license list, we could have performed active telephone follow-up and increased this rate. In this manner, we may have also been able to reduce possible selection biases. As a comparison, Knobeloch et al. (2007) were able to recruit > 2000 Wisconsin anglers through a variety of channels including press releases, TV and radio advertisements, newsletters  90
  and contacting various State agencies. They also established a toll-free telephone number to stimulate recruitment. While conducting telephone interviews helped subjects answer the questionnaire, offering the questionnaire in another format may have increased the participation rate. For example, a number of participants inquired about an online version of the questionnaire. In the future, providing both online and telephone questionnaire options may increase enrollment by attracting subjects who would prefer to complete the questionnaire online while retaining those who would prefer to conduct the questionnaire over the telephone.  4.8.3 Applicability of the Study Results 
 The study was intended to reflect exposure among recreational anglers on Vancouver Island. A predicted limitation to this approach was that the results would only be applicable to recreational anglers with similar consumption habits as this population. While we were hoping to recruit an ethnically diverse study population, the study population was overwhelmingly Canadian. Conducting this study in areas with a larger East Asian population, such as the Greater Vancouver area, would be a more efficient way of capturing exposures among this subpopulation. Further, without a demographic breakdown of the list, we were unable to determine whether the study population accurately reflected all Vancouver Island anglers. While the best estimations were made using other data sources, understanding how the study population compared would have increased our confidence in the applicability of the results. Finally, CFIA data and other Canadian studies that examined fish tissue-mercury concentrations were used to help explain the results of this study. Ideally, it would have been beneficial to use data specific to Vancouver Island. However, because many caught and bought fish species, i.e. tuna and salmon, originate from the same fishing grounds, and because there is a general lack of locally available data, national tissue-mercury concentration data were used to represent concentrations found in Vancouver Island fish. Tissue-mercury levels in fish are just one of the  91
  factors that influence exposure. Despite potential differences between CFIA estimates and actual concentrations in Vancouver Island fish, portion size and the frequency of fish consumption also have substantial impacts on exposure to methylmercury. However, the ability to explain why certain unexpected species were predictors of exposure could be improved with region-specific tissue-mercury data. This was particularly true for cutthroat trout and crab where tissue-mercury estimates were either missing or varied depending on species and/or where they were caught. Therefore, while national mercury data was helpful, obtaining tissue-mercury levels that accurately reflect those found in the Pacific Northwest would better explain the results of this study.  4.9 Future Studies 
 A number of recommendations can be made to improve this study.  4.9.1 Recruitment 
 Focusing on the recruitment of other ethnicities would help to identify any differences in exposure among anglers from different cultural backgrounds. This could be done by mailing research materials in other languages or by travelling to the study area to recruit anglers in person. This could also be accomplished by specifically studying a certain ethnic group, which has been the goal of other studies, such as those that investigated exposure among First Nations populations (Canuel et al., 2006; Wheatley & Paradis, 1995).  4.9.2 Questionnaire 
 Creating a more accurate portion size estimate would be another way to improve this study. One way to do this, while not drastically increasing the length of the questionnaire, would be to specifically ask for portion sizes of canned tuna and shellfish only. This way, finfish estimates would remain the same but a more accurate estimate for these subgroups would be attained. A section asking specifically about sushi/sashimi should also be created and portion sizes should also be tailored for this section. In addition, recruiting a test population and administering a  92
  dietary diary would help to validate consumption information and limit any under/over estimations of portion size and consumption frequency. Elaborating on certain fish species may help to better predict which species are true predictors of exposure.  For example, when subjects report consuming snapper, a secondary question  evaluating whether the subject was referring to pacific snapper, mangrove snapper and/or red snapper, etc. would reduce the uncertainty surrounding the misidentification of these species. Similarly, crab should be considered independently from ‘shellfish’ and differentiated into specific species, i.e. Dungeness, Rock, Snow, etc. Further, identifying canned tuna products by their common names, i.e. ‘white’ or ‘light’, as well as by species, would likely improve the reporting accuracy of these species.  4.9.3 Other Possibilities 
 Including a longitudinal component to this study may be beneficial to examine mercury exposure over time. A number of subjects expressed interest in this approach and were willing to follow their results over the years. This would obviously be dependent upon available resources but would provide valuable long-term information on fish consumption habits and exposure. Further, since arguably all of the fish species that were predictors of exposure were saltwater species, perhaps the focus should be less on whether fish are caught or bought, but on whether they come from freshwater or saltwater. This would be especially true for a location like Vancouver Island where there is ample access to both types of fish sources. However, in areas where there is a greater discrepancy between these sources, such as the BC interior, a caught versus bought approach may be more beneficial. Or, maintaining the focus on Vancouver Island, separate exposure groups could be established to better evaluate exposure resulting from caught or bought sources, i.e. compare blood-mercury results between those who only eat recreational fish with individuals who only consume commercial fish species. Another aspect of this study that could be expanded upon includes examining the proportion of anglers that share their catch. Since the health effects of mercury exposure differ depending on  93
  age and sex, and fish consumption is the primary source of exposure, it would be beneficial to determine who anglers share their catch with and in what frequencies. Gobeille et al. (2006) determined that two-thirds of recreational anglers who fish the Hudson River share their catch. Given that 80% of Vancouver Island recreational anglers are male, it would be interesting to determine if they were sharing their catch with their spouses, children and grandchildren; groups who may be affected by mercury differently than the angler.  94
  5. Conclusion 
 Overall, the study was able to answer the majority of the research questions. Using a multiple regression model that incorporated commonly consumed recreational and commercial fish species, caught rockfish, shellfish and cutthroat trout as well as bought albacore tuna, other tuna and snapper were all found to be independent predictors of mercury exposure. While the model demonstrated that an increase in the consumption of these species resulted in increased bloodmercury concentrations, it was important to note that blood-mercury levels among the anglers were below Health Canada guidelines. Our study supported previous research that found that frequent consumption of fish species containing moderate amounts of mercury was the most important in predicting exposure.  Our results also supported studies that demonstrated an  increase in blood-mercury with age, in males and with increasing income. Unfortunately, we were unable to fully examine the effect of ethnicity on exposure, mainly because of privacy restrictions on study recruitment methods as well as other study limitations. With these results, a number of policy developments can take place, primarily the focus on and continued examination of rockfish, cutthroat trout, crab and potentially lingcod, as predictors of mercury exposure.  The main goal of the study was to determine whether recreational or  commercial sources of fish contributed the most to exposure. Through our regression model, we found that the contribution was relatively equal with three predictors of exposure being caught species and three being bought species.  Even with the limitations, the study was able to  accurately examine the three determinants of mercury exposure when consuming fish (consumption frequency, species and portion size) and will contribute to the literature surrounding this important issue, particularly in British Columbia where recreational angling is a popular activity.  95
  References Agency for Toxic Substances and Disease Registry (ATSDR). (1999). Toxicological profile for mercury. Retrieved from http://www.atsdr.cdc.gov/toxprofiles/tp46.pdf Al-Majed, N. B., & Preston, M. R. (2000). Factors influencing the total mercury and methyl mercury in the hair of the fishermen of Kuwait. Environmental Pollution (Barking, Essex: 1987), 109(2), 239-250. Aqualibrium Environmental Consulting Inc. (2002). Fish mercury database summary - 2001: British Columbia. Retrieved from http://www.globalmercuryproject.org/database/Upload/Canada%202001%20Baker%20BC %20Hydro%20Mercury%20Database%20report.pdf Bjornberg, K. A., Vahter, M., Grawe, K. P., & Berglund, M. (2005). Methyl mercury exposure in Swedish women with high fish consumption. The Science of the Total Environment, 341(13), 45-52. Bodaly, R. A., Jansen, W. A., Majewski, A. R., Fudge, R. J., Strange, N. E., Derksen, A. J., et al. (2007). Postimpoundment time course of increased mercury concentrations in fish in hydroelectric reservoirs of northern Manitoba, Canada. Archives of Environmental Contamination and Toxicology, 53(3), 379-389. British Columbia Ministry of Agriculture. (2011). British Columbia seafood industry - year in review 2009. Retrieved from http://www.env.gov.bc.ca/omfd/reports/YIR-2009.pdf British Columbia Ministry of Environment. (2007). Sport fish of B.C. Retrieved July 8, 2009, from http://www.env.gov.bc.ca/fw/fish/sport_fish/ Brodkin, E., Copes, R., Mattman, A., Kennedy, J., Kling, R., & Yassi, A. (2007). Lead and mercury exposures: Interpretation and action. CMAJ : Canadian Medical Association Journal = Journal De l'Association Medicale Canadienne, 176(1), 59-63.  96
  Burger, J., & Gochfeld, M. (2004). Mercury in canned tuna: White versus light and temporal variation. Environmental Research, 96(3), 239-249. Burger, J., & Gochfeld, M. (2007). Risk to consumers from mercury in pacific cod (gadus macrocephalus) from the Aleutians: Fish age and size effects. Environmental Research, 105(2), 276-284. Burger, J., Stern, A. H., & Gochfeld, M. (2005). Mercury in commercial fish: Optimizing individual choices to reduce risk. Environmental Health Perspectives, 113(3), 266-271. Canuel, R., de Grosbois, S. B., Atikesse, L., Lucotte, M., Arp, P., Ritchie, C., et al. (2006). New evidence on variations of human body burden of methylmercury from fish consumption. Environmental Health Perspectives, 114(2), 302-306. Cole, D. C., Kearney, J., Sanin, L. H., Leblanc, A., & Weber, J. P. (2004). Blood mercury levels among Ontario anglers and sport-fish eaters. Environmental Research, 95(3), 305-314. Compeau, G. C., & Bartha, R. (1985). Sulfate-reducing bacteria: Principal methylators of mercury in anoxic estuarine sediment. Applied and Environmental Microbiology, 50(2), 498-502. Copes, R., Clark, N. A., Rideout, K., Palaty, J., & Teschke, K. (2008). Uptake of cadmium from pacific oysters (crassostrea gigas) in British Columbia oyster growers. Environmental Research, 107(2), 160-169. Dabeka, R., McKenzie, A. D., Forsyth, D. S., & Conacher, H. B. (2004). Survey of total mercury in some edible fish and shellfish species collected in Canada in 2002. Food Additives and Contaminants, 21(5), 434-440. Debruyn, A. M., Trudel, M., Eyding, N., Harding, J., McNally, H., Mountain, R., et al. (2006). Ecosystemic effects of salmon farming increase mercury contamination in wild fish. Environmental Science & Technology, 40(11), 3489-3493.  97
  Deniseger, J., Erickson, L. J., Austin, A., Roch, M., & Clark, M. J. R. (1990). The effects of decreasing heavy metal concentrations on the biota of Buttle Lake, Vancouver Island, British Columbia. Water Research, 24(4), 403-416. Fisheries and Oceans Canada. (2009). Finfish identification. Retrieved July 8, 2009, from http://www.pac.dfo-mpo.gc.ca/fm-gp/rec/species-especes/finident-identpoissoneng.htm#Dogfish Fisheries and Oceans Canada. (2011). Pacific region stats - annual comparison of sales entered into the tidal waters sportfishing (TWS) database and national recreational on-line system (NRLS). Retrieved April 8, 2011, from http://www.pac.dfo-mpo.gc.ca/fm-gp/rec/licencepermis/Stats/99tocurrent-feb-11.pdf Forsyth, D. S., Casey, V., Dabeka, R. W., & McKenzie, A. (2004). Methylmercury levels in predatory fish species marketed in Canada. Food Additives and Contaminants, 21(9), 849856. Gardner, R. M., Nyland, J. F., & Silbergeld, E. K. (2010). Differential immunotoxic effects of inorganic and organic mercury species in vitro. Toxicology Letters, 198(2), 182-190. Gobeille, A. K., Morland, K. B., Bopp, R. F., Godbold, J. H., & Landrigan, P. J. (2006). Body burdens of mercury in lower Hudson River area anglers. Environmental Research, 101(2), 205-212. Grandjean, P., Weihe, P., Jorgensen, P. J., Clarkson, T., Cernichiari, E., & Videro, T. (1992). Impact of maternal seafood diet on fetal exposure to mercury, selenium, and lead. Archives of Environmental Health, 47(3), 185-195. Grandjean, P., White, R. F., Weihe, P., & Jorgensen, P. J. (2003). Neurotoxic risk caused by stable and variable exposure to methylmercury from seafood. Ambulatory Pediatrics: The Official Journal of the Ambulatory Pediatric Association, 3(1), 18-23.  98
  GSGislason & Associates Ltd., Edna Lam Consulting, BriLev Consulting Inc, & Ellen F. Battle Consulting Inc. (2009). Freshwater sport fishing in British Columbia - sending ripples through the provincial economy. Retrieved from http://www.gofishbc.com/docs/freshwater%20sport%20fishing%20in%20bc.pdf Guallar, E., Sanz-Gallardo, M. I., van't Veer, P., Bode, P., Aro, A., Gomez-Aracena, J., et al. (2002). Mercury, fish oils, and the risk of myocardial infarction. The New England Journal of Medicine, 347(22), 1747-1754. Hankin, J. H. (1986). 23rd Lenna Frances Cooper memorial lecture: A diet history method for research, clinical, and community use. Journal of the American Dietetic Association, 86(7), 868-872. Harada, M. (1995). Minamata disease: Methylmercury poisoning in Japan caused by environmental pollution. Critical Reviews in Toxicology, 25(1), 1-24. Health Canada. (2007a). Human health risk assessment of mercury in fish and health benefits of fish consumption. Retrieved from http://www.hc-sc.gc.ca/fn-an/alt_formats/hpfbdgpsa/pdf/nutrition/merc_fish_poisson-eng.pdf Health Canada. (2007b). Mercury: Your health and the environment. Retrieved March 12, 2009, from http://www.hc-sc.gc.ca/ewh-semt/pubs/contaminants/mercur/q57-q72-eng.php Health Canada. (2008). Mercury in fish - consumption advice: Making informed choices about fish. Retrieved April 14, 2011, from http://www.hc-sc.gc.ca/fn-an/securit/chemchim/environ/mercur/cons-adv-etud-eng.php Health Canada. (2010). Report on human biomonitoring of environmental chemicals in Canada: Results of the Canadian health measures survey cycle 1 (2007-2009). Retrieved from http://www.hc-sc.gc.ca/ewh-semt/alt_formats/hecs-sesc/pdf/pubs/contaminants/chmsecms/report-rapport-eng.pdf HealthLink BC. (2011). BC health files - eating healthy: Choose fish low in mercury. Retrieved April 8, 2011, from http://www.healthlinkbc.ca/healthfiles/hfile68m.stm 99
  Hightower, J. M., & Moore, D. (2003). Mercury levels in high-end consumers of fish. Environmental Health Perspectives, 111(4), 604-608. Hornung, R. W., & Reed, L. D. (1990). Estimation of average concentration in the presence of nondetectable values. Applied Occupational and Environmental Hygiene., 5(1), 46-51. Innis, S. M., Palaty, J., Vaghri, Z., & Lockitch, G. (2006). Increased levels of mercury associated with high fish intakes among children from Vancouver, Canada. The Journal of Pediatrics, 148(6), 759-763. International Programme on Chemical Safety (IPCS). (1989). Mercury - environmental aspects. Retrieved April 8, 2011, from http://www.inchem.org/documents/ehc/ehc/ehc086.htm#SectionNumber:3.1 International Programme on Chemical Safety (IPCS). (1990). Environmental health criteria 101 - methylmercury. Retrieved April 8, 2011, from http://www.inchem.org/documents/ehc/ehc/ehc101.htm Jacquet, J. L., & Pauly, D. (2008). Trade secrets: Renaming and mislabeling of seafood. Marine Policy, 32(3), 309-318. Jewett, S. C., Zhang, X., Sathy Naidu, A., Kelley, J. J., Dasher, D., & Duffy, L. K. (2003). Comparison of mercury and methylmercury in northern pike and arctic grayling from western Alaska rivers. Chemosphere, 50(3), 383-392. Johnsson, C., Sallsten, G., Schutz, A., Sjors, A., & Barregard, L. (2004). Hair mercury levels versus freshwater fish consumption in household members of Swedish angling societies. Environmental Research, 96(3), 257-263. Knobeloch, L., Anderson, H. A., Imm, P., Peters, D., & Smith, A. (2005). Fish consumption, advisory awareness, and hair mercury levels among women of childbearing age. Environmental Research, 97(2), 220-227.  100
  Knobeloch, L., Gliori, G., & Anderson, H. (2007). Assessment of methylmercury exposure in Wisconsin. Environmental Research, 103(2), 205-210. Kosatsky, T., Przybysz, R., & Armstrong, B. (2000). Mercury exposure in Montrealers who eat St. Lawrence River sportfish. Environmental Research, 84(1), 36-43. Krebs-Smith, S. M., Heimendinger, J., Subar, A. F., Patterson, B. H., & Pivonka, E. (1995). Using food frequency questionnaires to estimate fruit and vegetable intake: Association between the number of questions and total intakes. Journal of Nutrition Education, 27(2), 80-85. Legrand, M., Feeley, M., Tikhonov, C., Schoen, D., & Li-Muller, A. (2010). Methylmercury blood guidance values for Canada. Canadian Journal of Public Health. Revue Canadienne De Sante Publique, 101(1), 28-31. Lincoln, R. A., Shine, J. P., Chesney, E. J., Vorhees, D. J., Grandjean, P., & Senn, D. B. (2011). Fish consumption and mercury exposure among Louisiana recreational anglers. Environmental Health Perspectives, 119(2), 245-251. Lorscheider, F. L., Vimy, M. J., & Summers, A. O. (1995). Mercury exposure from "silver" tooth fillings: Emerging evidence questions a traditional dental paradigm. The FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology, 9(7), 504-508. Lucas, F., Niravong, M., Villeminot, S., Kaaks, R., & Clavel-Chapelon, F. (1995). Estimation of food portion size using photographs: Validity, strengths, weaknesses and recommendations. Journal of Human Nutrition and Dietetics, 8, 65-74. Mahaffey, K. R., & Mergler, D. (1998). Blood levels of total and organic mercury in residents of the upper St. Lawrence River basin, Quebec: Association with age, gender, and fish consumption. Environmental Research, 77(2), 104-114.  101
  Mailman, M., Stepnuk, L., Cicek, N., & Bodaly, R. A. (2006). Strategies to lower methyl mercury concentrations in hydroelectric reservoirs and lakes: A review. The Science of the Total Environment, 368(1), 224-235. Marko, P. B., Lee, S. C., Rice, A. M., Gramling, J. M., Fitzhenry, T. M., McAlister, J. S., et al. (2004). Fisheries: Mislabelling of a depleted reef fish. Nature, 430(6997), 309-310. Matthews, A. D. (1983). Mercury content of commercially important fish of the Seychelles, and hair mercury levels of a selected part of the population. Environmental Research, 30(2), 305-312. McKelvey, W., Gwynn, R. C., Jeffery, N., Kass, D., Thorpe, L. E., Garg, R. K., et al. (2007). A biomonitoring study of lead, cadmium, and mercury in the blood of New York city adults. Environmental Health Perspectives, 115(10), 1435-1441. Moran, P. W., Aluru, N., Black, R. W., & Vijayan, M. M. (2007). Tissue contaminants and associated transcriptional response in trout liver from high elevation lakes of Washington. Environmental Science & Technology, 41(18), 6591-6597. Mozaffarian, D. (2009). Fish, mercury, selenium and cardiovascular risk: Current evidence and unanswered questions. International Journal of Environmental Research and Public Health, 6(6), 1894-1916. Mozaffarian, D., & Rimm, E. B. (2006). Fish intake, contaminants, and human health: Evaluating the risks and the benefits. JAMA : The Journal of the American Medical Association, 296(15), 1885-1899. Nagpal, N. K. (1989). Ambient water quality criteria for mercury: Technical appendix. Retrieved from British Columbia Ministry of Environment website: http://www.env.gov.bc.ca/wat/wq/BCguidelines/mercury/mercurytech.pdf Nielsen, J. B., & Andersen, O. (1996). Elimination of recently absorbed methyl mercury depends on age and gender. Pharmacology & Toxicology, 79(2), 60-64.  102
  Nieuwenhuijsen, M. J. (2003). Questionnaires. Exposure assessment in occupational and environmental epidemiology (pp. 21-38). New York: Oxford University Press. Nilsson, N. -A., & Northcote, T. G. (1981). Rainbow trout (salmo gairdneri) and cutthroat trout (S. clarki) interactions in coastal British Columbia lakes. Canadian Journal of Fisheries and Aquatic Sciences, 38(10), 1228-1246. O'Neil, D. (2007). Census fast facts - ageing of the British Columbia population. Retrieved from BC Stats website: http://www.bcstats.gov.bc.ca/data/cen06/facts/cff0601.pdf Phelps, R. W., Clarkson, T. W., Kershaw, T. G., & Wheatley, B. (1980). Interrelationships of blood and hair mercury concentrations in a North American population exposed to methylmercury. Archives of Environmental Health, 35(3), 161-168. Rhainds, M., Levallois, P., Dewailly, E., & Ayotte, P. (1999). Lead, mercury, and organochlorine compound levels in cord blood in Quebec, Canada. Archives of Environmental Health, 54(1), 40-47. Rieberger, K. (1992). Metal concentrations in fish tissue from uncontaminated B.C. lakes. Retrieved from British Columbia Ministry of Environment website: http://www.env.gov.bc.ca/wat/wq/reference/metalinfish.pdf Serdula, M., Byers, T., Coates, R., Mokdad, A., Simoes, E. J., & Eldridge, L. (1992). Assessing consumption of high-fat foods: The effect of grouping foods into single questions. Epidemiology (Cambridge, Mass.), 3(6), 503-508. Shatenstein, B., Kosatsky, T., Nadon, S., Lussier-Cacan, S., & Weber, J. P. (1999). Reliability and relative validity of fish consumption data obtained in an exposure assessment study among Montreal-area sportfishers. Environmental Research, 80(2 Pt 2), S71-S86. Sidhu, K. S. (2003). Health benefits and potential risks related to consumption of fish or fish oil. Regulatory Toxicology and Pharmacology: RTP, 38(3), 336-344.  103
  Sigler, J. M., Lee, X., & Munger, W. (2003). Emission and long-range transport of gaseous mercury from a large-scale Canadian boreal forest fire. Environmental Science & Technology, 37(19), 4343-4347. Statistics Canada. (2009). Canadian community health survey (CCHS) - 2009 questionnaire. Retrieved from http://www.statcan.gc.ca/imdb-bmdi/instrument/3226_Q1_V6-eng.pdf Stern, A. H. (1993). Re-evaluation of the reference dose for methylmercury and assessment of current exposure levels. Risk Analysis: An Official Publication of the Society for Risk Analysis, 13(3), 355-364. Sunderland, E. M. (2007). Mercury exposure from domestic and imported estuarine and marine fish in the U.S. seafood market. Environmental Health Perspectives, 115(2), 235-242. Thompson, F. E., & Byers, T. (1994). Dietary assessment resource manual. The Journal of Nutrition, 124(11 Suppl), 2245S-2317S. United States Environmental Protection Agency (EPA). (1997). Mercury study report to congress - volume II: An inventory of anthropogenic mercury emissions in the United States. Retrieved from http://www.epa.gov/ttncaaa1/t3/reports/volume2.pdf United States Environmental Protection Agency (EPA). (2001a). Mercury update: Impact on fish advisories. Retrieved March 2, 2009, from http://www.epa.gov/waterscience/fish/advice/mercupd.pdf United States Environmental Protection Agency (EPA). (2001b). Water quality criterion for the protection of human health: Methylmercury. Retrieved from http://water.epa.gov/scitech/swguidance/standards/criteria/aqlife/pollutants/methylmercury/ upload/2009_01_15_criteria_methylmercury_mercury-criterion.pdf United States Environmental Protection Agency (EPA). (2010). Mercury - basic information. Retrieved April 8, 2011, from http://www.epa.gov/hg/about.htm  104
  University of Victoria. (No Date). Island Copper Mine fonds (acc. no. 2000-069). Retrieved May 15, 2011, from http://library.uvic.ca/site/archives/featured_collections/esa/fonds_island_copper_mines/defa ult.html Weech, S. A., Scheuhammer, A. M., Elliott, J. E., & Cheng, K. M. (2004). Mercury in fish from the Pinchi Lake region, British Columbia, Canada. Environmental Pollution (Barking, Essex : 1987), 131(2), 275-286. Weiner, J. A., & Nylander, M. (1995). An estimation of the uptake of mercury from amalgam fillings based on urinary excretion of mercury in Swedish subjects. The Science of the Total Environment, 168(3), 255-265. Wheatley, B., & Paradis, S. (1995). Exposure of Canadian aboriginal peoples to methylmercury. Water, Air, and Soil Pollution, 80, 3-11. WorkSafe BC. (2011). 2010 - browse the classification structure by sector. Retrieved April 8, 2011, from http://www.worksafebc.com/insurance/premiums/2010_rates/classification/browse_sectors_ and_subsectors/default.asp Yamashita, Y., Omura, Y., & Okazaki, E. (2005). Total mercury and methylmercury levels in commercially important fishes in Japan. Fisheries Science, 71, 1029-1035. Yokoo, E. M., Valente, J. G., Grattan, L., Schmidt, S. L., Platt, I., & Silbergeld, E. K. (2003). Low level methylmercury exposure affects neuropsychological function in adults. Environmental Health: A Global Access Science Source, 2(1), 8.  105
  Appendices Appendix A: Literature Review Strategy 
 PubMed and Google Scholar were used to identify relevant, peer-reviewed academic studies. There was no timeframe set for the search primarily because of the limited number of studies that have been conducted in this field.  Keywords such as “mercury”, “fish”, “anglers”,  “commercial”, “recreational”. “exposure” and “fish species” were all entered to locate studies. From important articles, references to other relevant studies were identified and reviewed. Including “mercury” and “fish” alone generated 2500 articles in PubMed, however adding “exposure” and “commercial” reduced that number to 21. Removing “commercial” and adding “sport fish” only generated 3 studies. Government websites, public health agency websites and grey literature were found using Google to locate background information on mercury, such as the health effects of exposure, sources of mercury in the environment as well as statistics pertaining to the state of the BC recreational fishing industry. 
 
 
 
 
 
 
 
 
 
 
 
 
 
  106
  Appendix B: Histograms and Quantile Plots of the Blood-Mercury Distribution 
 As illustrated in Figure 7, the untransformed blood-mercury data was skewed to the right, which is typical of exposure data. The skewness of the untransformed distribution was 1.88 and the kurtosis was 4.84, indicating the asymmetry of the distribution. Figure 8 illustrates the logtransformed data, which had a skewness of -0.40 and a kurtosis of 0.27, suggesting that the blood-mercury data was log-normally distributed. Visual inspections of the quantile plots of the untransformed blood-mercury data and log-transformed data also suggest the lognormal distribution of the blood sample results. Examining the quantile plot of the untransformed data (Figure 9), the distribution does not follow the plot of a normal distribution. In contrast, the quantile plot of the log-transformation (Figure 10) sufficiently follows a lognormal distribution.  Figure 7. Untransformed blood-mercury distribution. 
  107
  Figure 8. Log-transformed blood-mercury distribution. 
  Figure 9. Quantile plot of untransformed blood-mercury distribution. 
 108
  Figure 10. Quantile plot of log-transformed blood-mercury distribution.  109
  Appendix C: Complete Recreationally Caught Fish Consumption Report Table 24. Number of anglers who reported consuming each recreationally caught fish species. Fish Species # of Anglers Who Consumed Percent of Population (%) Salmon 161 82.6 * Shellfish 118 60.5 Rainbow Trout 88 45.1 Halibut 78 40.0 Lingcod 52 26.7 Rockfish 46 23.6 Cutthroat Trout 43 22.1 Albacore Tuna 11 5.6 Steelhead Trout 10 5.1 Sablefish 7 3.6 Smallmouth Bass 6 3.1 Sole 6 3.1 Kokanee 5 2.6 Greenling 5 2.6 Cod 4 2.1 Cabazon 3 1.5 Lake Trout 2 1.0 Herring 2 1.0 Surf Perch 2 1.0 Yellowtail 2 1.0 Sea Bass 2 1.0 Other Tuna 1 0.5 Brook Trout 1 0.5 Mackerel 1 0.5 Flounder 1 0.5 Pickerel 1 0.5 Octopus 1 0.5 Squid 1 0.5 * Shellfish includes shrimp, prawns, crabs, mussels, oysters and clams 
 
 
 
 
 
 
 
 
  110
  Appendix D: Complete Commercially Bought Fish Consumption Report 
 Table 25. Number of anglers who reported consuming each commercially bought fish species. Fish Species Shellfish* Halibut Salmon Canned Other+ Tuna Sardine Canned Albacore Tuna Cod Sole Snapper Pollock Lingcod Herring Processed Fish  # of Anglers Who Consumed 133 124 123  Percent Fish Species (%) 68.2 Sea Bass 63.6 Perch 63.1 Swordfish  # of Anglers Who Consumed 4 4 3  Percent (%) 2.1 2.1 1.5  74  37.9  Monkfish  3  1.5  74  37.9  Flounder  3  1.5  71  36.4  Orange Roughy  2  1.0  64 63 53 51 43 39 36  32.8 32.3 27.2 26.2 22.1 20.0 18.5  2 2 2 2 2 2 2  1.0 1.0 1.0 1.0 1.0 1.0 1.0  Other+ Tuna^  33  16.9  1  0.5  Basa Albacore Tuna^ Sablefish Tilapia Mahi Mahi Rainbow Trout Mackerel Eel Unknown Sushi Haddock  30 24 21 21 19 15 7 7 7 6  15.4 12.3 10.8 10.8 9.7 7.7 3.6 3.6 3.6 3.1  1 1 1 1 1 1 1 1 1 1  0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5  Squid  6  3.1  Other Trout Kokanee Arctic Char Burbot Yellowtail Anchovy Rockfish Smallmouth Bass Marlin Cutthroat Trout Turbot Baramundi Sea Cucumber Blue Fish Urchin Blue Cod Skate White Bait Unknown Whitefish  1  0.5  Steelhead Trout 5 2.6 * Shellfish includes shrimp, prawns, crabs, mussels, oysters and clams + ‘Other’ refers to species that are not albacore, i.e. skipjack, yellowfin, ahi, etc. ^ Fresh or frozen  111
  Appendix E: Simple Linear Regression Results for Fish Species Reported by ≥ 5% of the Study Population Table 26: Simple linear regression results for each recreationally caught and commercially consumed fish species reported by ≥ 5% of the study population. Species are listed in order of descending adjusted R2 values.  Caught Lingcod  Coefficient (ln µg/L blood-Hg per g/week) 4.13 x 10-3  Standard Error 1.29 x 10-3  Model P-Value* 0.002  Adjusted R2 0.045  Caught Rockfish  3.91 x 10-3  1.25 x 10-3  0.002  0.043  Bought Other+ Tuna^  3.57 x 10-3  1.16 x 10-3  0.002  0.042  2.55 x 10  -3  8.62 x 10  -3  0.003  0.039  1.96 x 10  -3  6.71 x 10  -4  0.004  0.037  9.37 x 10  -4  3.42 x 10  -4  Fish Species  Bought Albacore Tuna  ^  Caught Halibut Caught Shellfish  *  0.007  0.033  Bought Snapper  3.75 x 10-3  1.78 x 10-3  0.036  0.018  Bought Herring  -4  3.25 x 10  -4  0.070  0.014  3.53 x 10  -4  0.104  0.009  1.94 x 10  -4  -5.92 x 10 5.77 x 10  -4  Caught Salmon  2.98 x 10  -4  0.126  0.007  Bought Rainbow Trout  7.01 x 10-3  4.71 x 10-3  0.138  0.006  1.37 x 10  -3  9.41 x 10  -4  0.148  0.006  2.66 x 10  -3  1.95 x 10  -3  0.174  0.004  Bought Sablefish  5.28 x 10  -3  3.99 x 10  -3  0.187  0.004  Caught Steelhead Trout  -4.22 x 10-3  3.34 x 10-3  0.209  0.003  1.15 x 10  -3  9.52 x 10  -4  0.227  0.002  1.36 x 10  -3  1.24 x 10  -3  0.274  0.001  3.02 x 10  -4  Bought Salmon  Bought Halibut Caught Cutthroat Trout  Bought Lingcod Bought Sole +  -4  Bought Other Canned Tuna  -2.63 x 10  0.385  -0.001  Bought Cod  -1.23 x 10-3  1.63 x 10-3  0.450  -0.002  -3  1.62 x 10  -3  0.486  -0.003  6.99 x 10  -4  0.521  -0.003  2.11 x 10  -3  Bought Processed Fish Caught Rainbow Trout  -1.13 x 10 4.50 x 10  -4 -3  Bought Tilapia  -1.01 x 10  0.632  -0.004  Bought Canned Albacore Tuna  1.81 x 10-4  4.70 x 10-4  0.701  -0.004  -4  4.56 x 10  -4  0.769  -0.005  8.02 x 10  -4  0.823  -0.005  5.43 x 10  -4  Bought Shellfish Bought Pollock  -1.34 x 10 1.80 x 10  -4 -5  Caught Albacore Tuna  -9.44 x 10  0.862  -0.005  Bought Sardine  -9.02 x 10-5  5.33 x 10-4  0.866  -0.005  -4  4.18 x 10  -3  0.893  -0.005  Bought Basa -3.33 x 10 3.40 x 10 α=0.05 * Shellfish includes shrimp, prawns, crabs, mussels, oysters and clams + ‘Other’ refers to species that are not albacore, i.e. skipjack, yellowfin, ahi, etc. ^ Fresh or frozen  -3  0.922  -0.005  Bought Mahi Mahi  5.66 x 10  -4  *  112
  Appendix F: Initial Results of the Multiple Linear Regression Model Table 27. Initial multiple regression model for the dependent variable blood-mercury concentration (µg/L) and the independent variables meeting the model inclusion criteria. N*  Coefficient  Standard Error  P-value  Model 195 0.0001 -1 -1 Intercept 8.57 x 10 3.93 x 10 0.0305 Total Caught Fish Consumption (g/week) 195 2.22 x 10-5 2.05 x 10-4 0.2792 -3 -3 Caught Rockfish (g/week) 195 2.84 x 10 1.55 x 10 0.0684 Caught Lingcod (g/week) 195 1.57 x 10-3 1.83 x 10-3 0.3908 -4 -4 Caught Halibut (g/week) 195 -5.02 x 10 9.49 x 10 0.5979 -4 -4 Caught Shellfish (g/week) 195 5.09 x 10 3.53 x 10 0.1515 Caught Cutthroat Trout (g/week) 195 3.68 x 10-3 1.86 x 10-3 0.0490 -5 -4 Total Bought Fish Consumption (g/week) 195 1.98 x 10 2.34 x 10 0.9327 Bought Other Tuna (g/week) 195 3.13 x 10-3 1.36 x 10-3 0.0224 -3 -3 Bought Albacore Tuna (g/week) 195 2.76 x 10 1.09 x 10 0.0120 Bought Snapper (g/week) 195 4.98 x 10-3 2.14 x 10-3 0.0212 -4 -3 Bought Salmon (g/week) 195 2.85 x 10 4.27 x 10 0.5046 -3 -3 Bought Rainbow Trout (g/week) 195 4.34 x 10 4.90 x 10 0.3769 Bought Halibut (g/week) 195 4.76 x 10-4 1.06 x 10-3 0.6527 -3 -3 Bought Sablefish (g/week) 195 -4.42 x 10 4.92 x 10 0.3711 Bought Lingcod (g/week) 195 -1.15 x 10-3 1.10 x 10-3 0.2960 -4 -3 Bought Sole (g/week) 195 -4.18 x 10 1.40 x 10 0.7650 Bought Canned Albacore Tuna (g/week) 195 1.30 x 10-4 4.96 x 10-3 0.7933 -3 -3 Age (years) 195 2.42 x 10 3.94 x 10 0.5405 Sex 195 0.5048 -2 -2 Female 39 -5.17 x 10 7.74 x 10 0.5048 Estimated Ethnicity 1 195 0.0089 Other 20 3.28 x 10-1 1.24 x 10-1 0.0089 Estimated Ethnicity 2 195 0.2007 Other 39 -1.25 x 10-1 9.72 x 10-2 0.2007 Annual Income 195 0.2068 <$20,000 24 -2.39 x 10-1 1.48 x 10-1 0.1077 -2 -1 $40,000 - $59,999 45 5.94 x 10 1.11 x 10 0.5935 -2 -1 $60,000 - $79,999 29 -2.53 x 10 1.32 x 10 0.8478 >$80,000 31 2.98 x 10-1 0.0265 -2 -1 Decline 7 -6.86 x 10 2.35 x 10 0.7706 Body Weight (kg) 195 -4.45 x 10-3 3.77 x 10-3 0.2399 α=0.05 Adjusted R2 = 18.1% * Number of Observations Note: Male, Western Ethnicity and the income range of $20,000 - $39,999 were used as reference values, included in the intercept (β0)  
  113
  Appendix G: Study Letter of Initial Contact  ! Printed on UBC Letterhead  Dear Sir or Madam, We would like to invite you to participate in a research study investigating fish consumption and mercury exposure in British Columbian recreational anglers. The University of British Columbia’s School of Environmental Health needs the assistance of anglers like you to complete the study. You have been contacted through the BC Ministry of Environment’s Freshwater Angling License list with the permission of the BC Ministry of Environment and the UBC Clinical Research Ethics Board. Why are we performing this study? Mercury is a common metal that is present in lakes and oceans. Through chemical changes, mercury can be converted into methylmercury, which can be taken up by fish and other aquatic species. When humans are exposed to too much of it, it can have effects on the nervous system including muscle tremors, irritability and memory problems. Most people are exposed through eating fish. Public health officials recognize the link between fish consumption and exposure, and agencies including Health Canada and the BC Ministry of Health have developed recommendations to help people choose fish that contain lower amounts of methylmercury. However, there is little information on the relative contribution that ‘bought’ and ‘caught’ fish may have on overall exposure. The results of the study will determine how much methylmercury BC recreational anglers are exposed to and whether the majority of that exposure comes from the fish they catch or from the fish they buy. We also hope to determine any differences in exposure among anglers of different sex, income levels and ethnicity. How will your participation help the study? By participating in this study, you will help us determine how much methylmercury BC recreational anglers are exposed to and whether the majority of that exposure comes from the fish they catch or from the fish they buy. Your involvement could lead to changes in public fish consumption guidelines and will contribute to the knowledge surrounding the risks and benefits of eating fish.  Please Turn Over  114
  ! How do you benefit by participating in the study? • • •  You will receive a $25 gift certificate to Island Outfitters Sport Fishing Centre in appreciation for fully completing the study. Knowledge of your personal blood mercury levels with an explanation of the results. Knowledge that you are contributing to a study that could change public fish consumption guidelines as well as help us to better understand the priorities surrounding mercury monitoring in fish.  What would you have to do for the study? 1. Complete a 20-30 minute telephone questionnaire. 2. Provide a blood sample that will be analyzed for mercury. Please be assured that all personal information you provide to us will be kept strictly confidential and will never be published in any form. Please take your time to decide whether you would like to participate in this study. If you would like to participate, please contact the study coordinator, Mr. David Kodama, who will provide you with further instructions as to how the study will proceed. If you would like additional information before deciding, please feel free to also contact Mr. Kodama. We would like to thank you in advance for your time and hope you consider participating in this valuable and interesting study. Mr. David Kodama can be reached at:  604-827-3517 or dkodama@interchange.ubc.ca Sincerely,  ______________________________________________ Ray Copes, MD, Clinical Professor, UBC  _____________________________________________ David Kodama, MSc Candidate, UBC  115
  Appendix H: BC Ministry of Environment Letter of Initial Contact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`!<1%.+0241#%8&,,.+2'a(278/-8-$!! !  !  !  116
  Appendix I: Reminder Card  !"#$#%&'()*$+%$(,"-./%%  117
  Appendix J: Study Consent Form  Printed on UBC Letterhead  SUBJECT INFORMATION & CONSENT FORM Methylmercury exposures in British Columbian anglers who consume both recreationally caught and commercially bought fish. Principal Investigator:  Dr. Ray Copes, MD, MSc, DIH School of Population and Public Health ray.copes@ubc.ca 604-319-0370  Co-Investigators:  Dr. Hugh Davies, PhD, CIH School of Environmental Health 604-822-6777 David Kodama, BMSc, MSc Candidate School of Environmental Health dkodama@interchange.ubc.ca 604-827-3517  We would like to invite you to participate in a study investigating methylmercury exposures in British Columbian recreational anglers. Methylmercury is a common contaminate in fish and ingesting too much can lead to effects on the nervous system. The primary goal of this study is to determine exposure to methylmercury as a result of eating fish that is both caught and bought. The results of the study will be extremely important in helping public health agencies provide advice on fish consumption. As a BC fisherman, you will be able to provide important information on the extent of exposure within this large group of fish consumers. Your participation is entirely voluntary, so it is up to you to decide whether or not to take part in this study. Before you decide, it is important for you to understand what the research involves. This consent form will tell you about the study, why the research is being done, what will happen to you during the study and the possible benefits, risks and discomforts. If you wish to participate, you will be asked to sign this form. If you take part in this study, you are still free to withdraw at any time and without giving any reasons for your decision. If you do not wish to participate, you do not have to provide any reason for your decision not to participate. Deciding not to participate or withdrawing at any time during the study will not affect your fishing license status in any way. Please take time to read the following information carefully and to discuss it with your family and friends before you decide.  1  118
  WHAT IS THE PURPOSE OF THE STUDY? The purpose of the study is to examine blood methylmercury levels in recreational Vancouver Island anglers with a focus on determining exposure from commercially bought and recreationally caught fish. Relationships will also be examined between exposure and certain personal factors such as your place of birth, annual income level and gender. WHO CAN PARTICIPATE IN THE STUDY? Any person 19 years of age and older who holds an annual BC Freshwater Angling License is eligible to participate in the study. Those younger than 19 years of age or those who do not hold an annual BC Freshwater Angling License are not eligible to participate in the study. WHAT DOES THE STUDY INVOLVE? Should you choose to participate, your participation would include: 1. Answer a 20-30 minute telephone questionnaire *You do not have to answer any questions you do not feel comfortable answering 2. Provide a blood sample *This will require you to travel to the nearest LifeLabs® location WHAT ARE THE POSSIBLE HARMS AND SIDE EFFECTS OF PARTICIPATING? There are no potential harms or side effects from completing the questionnaire. There may be some discomfort and a potential for bruising at the site of the needle puncture during and after the blood sample collection, which is small (10mL, or 2 teaspoons) and taken at the forearm. The blood sample will only be tested for the presence of mercury. WHAT ARE THE BENEFITS OF PARTICIPATING IN THIS STUDY? Your personal blood methylmercury levels will be given to you and explained after the collection and analyses of the data. Further, should you complete the entirety of the study (i.e. answer the questionnaire and provide a blood sample), you will be given a $25 gift certificate to the Island Outfitters Sport Fishing Centre. Finally, you will be providing valuable information that may have a substantial societal impact in terms of reducing risks of mercury poisoning. However, there may or may not be direct health benefits to you from taking part in this study. WHAT HAPPENS IF I DECIDE TO WITHDRAW MY CONSENT TO PARTICIPATE? Your participation in this research is entirely voluntary. You may withdraw from this study or refuse to participate at any time without having to provide any reasons for doing so. Further, should you choose to withdraw, you do not have to answer any questions that you do not want to. If you decide to enter the study and to withdraw at any time in the future, there will be no penalty and your future angling license status will not be affected. However, please be aware that to receive the $25 gift certificate, the questionnaire must be completed and a blood sample must be provided. If you choose to enter the study and then decide to withdraw at a later time, all data collected about you during your enrolment in the study will be retained for analysis. By law, this data cannot be destroyed.  2  119
  WHAT HAPPENS IF SOMETHING GOES WRONG? Signing this consent form in no way limits your legal rights against the sponsor, investigators, or anyone else. WHAT WILL THE STUDY COST ME? Transportation to and from the LifeLabs® location where the blood sample is to be taken, as well as any outgoing long-distance phone calls to the study coordinator or contacts, will not be covered. There will be no other costs to you. WILL MY TAKING PART IN THIS STUDY BE KEPT CONFIDENTIAL? Your confidentiality will be respected. No information that discloses your identity will be released or published without your specific consent to the disclosure. However, research records and medical records identifying you may be inspected in the presence of the Investigator or his or her designate by representatives of the BC Ministry of Health and the UBC Research Ethics Board for the purpose of monitoring the research. However, no records that identify you by name or initials will be allowed to leave the Investigators' offices. WHO DO I CONTACT IF I HAVE QUESTIONS ABOUT THE STUDY DURING MY PARTICIPATION? If you have any questions, or desire further information with respect to this study, you may contact Mr. David Kodama (primary contact and study coordinator) at 604-827-3517 or dkodama@interchange.ubc.ca, or Dr. Ray Copes (Principal Investigator) at ray.copes@ubc.ca. WHO DO I CONTACT IF I HAVE ANY QUESTIONS OR CONCERNS ABOUT MY RIGHTS AS A SUBJECT DURING THE STUDY? If you have any concerns about your treatment or rights as a research subject, you may contact the Research Subject Information Line in the UBC Office of Research Services at 604822-8598 or if long distance e-mail to RSIL@ors.ubc.ca. WHAT HAPPENS ONCE THE STUDY IS FINISHED? Once your participation has concluded, we will send you a letter summarizing your blood methylmercury levels along with an explanation of what your levels mean. Your $25 gift certificate will also be mailed to you at this time. CONFLICT OF INTEREST The Investigators hereby declare that they have no known conflict of interest involving this study.  3  120
  SUBJECT CONSENT TO PARTICIPATE Your signature below indicates that you have read this consent and agree to participate in this study. • • • • • • • •  I have read and understood the subject information and consent form. I have had sufficient time to consider the information provided and to ask for advice if necessary. I have had the opportunity to ask questions and have had satisfactory responses to my questions. I understand that all of the information collected will be kept confidential and that the result will only be used for scientific objectives. I understand that my participation in this study is voluntary and that I am completely free to refuse to participate or to withdraw from this study at any time without providing and reasons. I understand that I am not waiving any of my legal rights as a result of signing this consent form. I have read this form and I freely consent to participate in this study. I have been told that I will receive a dated and signed copy of this form.  SIGNATURES The subject’s signature and printed name must be included before the signatures of the witness and the Principal Investigator/designate. ______________________________________________________________________________ Printed Name of Subject Signature Date  ______________________________________________________________________________ Printed Name of Witness Signature Date ______________________________________________________________________________ Printed Name of Principal Investigator/ Designated Representative Signature Date  4  121
  
  Appendix K: Study Instructions Letter  ! Dear Mr. or Mrs. (Insert Name), Thank you for taking the time to participate in this study. The information you provide will be invaluable in helping us examine methylmercury exposures in BC anglers. As you are aware, participation involves completing a 20-30 minute telephone questionnaire and providing a blood sample that will be analyzed for mercury only. This package contains 7 separate documents that you will need throughout the study. To ensure that you feel comfortable and informed throughout this process, we would like to provide you with the 3 steps that outline how the study will proceed over the next few weeks.  Step  1  Sign the Consent Form  Package Documents  2 Copies of the Consent Form  Your Task • • •  Complete the 2 Telephone Questionnaire  1 Document Entitled: Questionnaire Guide 1 Document Entitled: Estimating Your Fish Consumption  • •  Take your time to carefully read the form. Sign one of the copies and mail it to us in the provided envelope. You will receive a copy of this fully signed form once we receive and sign it. Keep the other copy for your own records. Please familiarize yourself with both documents before your interview. Have both documents with as you complete the telephone questionnaire, as the interviewer will ask you to refer to them throughout the process.  1 LifeLabs® Requisition Form 3  Provide a Blood Sample  1 BC Children and Women’s Hospital Requisition Form  •  Please take both requisition forms and a piece of photo ID to the LifeLabs® location of your choice to have your blood drawn free of charge.  1 Map of All Vancouver Island LifeLabs® Locations We will mail you your $25 gift certificate to Island Outfitters Sport Fishing Centre in appreciation for your time and effort once the results of the study have been analyzed. We will also mail you the results of your personal blood sample with an explanation of what they mean. If you have any questions, comments or concerns regarding any aspect of this study, please do not hesitate to contact us. We look forward to speaking with you on your telephone interview date at: XX:XX on DAY MONTH, 2010 Sincerely, David Kodama Study Coordinator dkodama@interchange.ubc.ca 604-827-3517  122
  
  Appendix L: Questionnaire Guide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
  
  Appendix M: Fish Consumption Guide  Estimating Your Fish Consumption In questions 6.2 and 7.2, the interviewer will ask you how much fish, on average, you eat at each meal. To help you provide an answer, pictures of fish portion sizes have been attached on pages 2 and 3. Since you may be more familiar with certain cuts of fish more than others, the pictures have been divided into two different categories: thick cuts of fish and thin cuts of fish. These cuts of fish have been placed onto a standard-sized dinner plate (101/4 inches) to help you recall how much you usually eat. Thick cuts refer to large fillets and steaks such as those from Salmon, Halibut and Tuna. These types of cuts tend to come from larger fish. Thin cuts refer to small fillets such as those that come from Trout and Sole. While there are many ways that you can eat fish, including canned fish, fish sticks, smoked fish, sushi, sashimi, etc., we are mainly interested in the total weight of fish you are eating. As such, each photo is associated with a weight of fish, ranging from 75g – 450g for both the thick and thin cuts. To help you better estimate your fish consumption when examining the thick and thin cuts of fish, pictures of the two most common sizes of canned Tuna are pictured directly below. The smaller can on the left contains 85g of Tuna while the larger can on the right contains 120g of Tuna. For your reference, a pen and ruler have been included in the picture. The ruler is just over 12 inches (30.5 cm) long.  In this study, the thick cuts are Salmon fillets and the thin cuts are Rainbow Trout fillets. The purpose of presenting both types of cuts is to provide you with the choice of cut that you are most familiar with. In questions 6.2 and 7.2, the interviewer will ask you to state which type of cut you are most familiar with. Once you make your selection, he will ask you to look through those specific photos (A-F for your cut of choice) and choose the one photo that best represents your typical portion size of fish.  !  "!  126
  THICK CUTS The thick cuts are Salmon fillets. The plate used in these photos is a standard dinner plate (101/4 inches) and the ruler above the plate is just over 12 inches (30.5 cm) long. Photo Letter  Fish Weight (g)  A  75  B  150  C  225  D  300  E  375  F  450  !  View 1  View 2  "!  127
  THIN CUTS The thin cuts are Rainbow Trout fillets. The plate used in these photos is a standard dinner plate (101/4 inches) and the ruler above the plate is just over 12 inches (30.5 cm) long. Photo Letter  Fish Weight (g)  A  75  B  150  C  225  D  300  E  375  F  450  !  View 1  View 2  "!  128
  
  Appendix N: Questionnaire  !"#$%&'()*(+",&-./01%#2( ! ! "#$!%&'()*+*,-)*.(!  ! B#$!>.()-,)!%(+.89-)*.(! !  ! H#$!6'I! ! L#$!;-)'!.+!=*8)F!  ! /*0'(1!233343334333433343334333433343334333433343334333433343334333433343335! ! 678(-9'1!23334333433343334333433343334333433343334333433343334333433343335! ! 6)7&:!%;1!<=>!?!@A6!?!2333433343335! ! ! 67*)'1!2333433343334333433343335! ! 6)8'')1!233343334333433343334333433343334333433343334333433343334333433343335! ! >*):1!233343334333433343334333433343334333433343334333433343334333433343335! ! C8.0*(,'1!233343335! ! C.D)-E!>.&'1!2333433343334333433343335! ! CF.('1!2333433343335G2333433343335G23334333433343335! ! ! J-E'2335"!!!!!K'9-E'2335B!!!!! ! ! J.()F!233343335! ! M'-8!23334333433343335! ! ;-:!233343335! !  (  
 129
  
  !"#$%&'()&*+,&-&./!&-&0111211121113& & ! ! "#$%&'(!)*!+#$,#-%&'(-.!/&01&(2!3(4',5-%&'(! & & & 567&/89:;<9&=#>?9:&@A&"B>9C&"D9&C#?E9F"C& I&J;%&477K&&&&&&&&&&&&&&&&011113&&&&&&&&IL&J;%&47I7&&&&&&&&&&&&01113& G9="&ABCDB=<&9;FD&>@="D&@89:&"D9&H;C"& 4&M#=9&477K&&&&&&&&&&&&&&&&011113&&&&&&&IN&M#=9&47I7&&&&&&&&&&&&&01113& %9;:& L&M#O%&477K&&&&&&&&&&&&&&&&&011113&&&&&&&I5&M#O%&47I7&&&&&&&&&&&&&&01113& & N&/#<#C"&477K&&&&&&&&&&&011113&&&&&&&IP&/#<#C"&47I7&&&&&&&&01113& & 5&!9H"9>?9:&477K&&&&011113&&&&&&IQ&!9H"9>?9:&47I7&01113& P&RF"@?9:&477K&&&&&&&&&&011113&&&&&&IS&RF"@?9:&47I7&&&&&&01113& Q&T@89>?9:&477K&&&&&011113& S&(9F9>?9:&477K&&&&&&011113& K&M;=#;:%&47I7&&&&&&&&&&011113& I7&U9?:#;:%&47I7&&&&&011113& II&J;:FD&47I7&&&&&&&&&&&011113& I4&/H:BO&47I7&&&&&&&&&&&&&&011113& &  &  4&  130
  !"#$%&'()&*+,&-&./!&-&0111211121113& !"#$%&'()*()&'+,-.$%&'(&/()0,12$(3%+2( & & 567&89":;&<:#=>"&?@A>&<9BA#CD"@9B&?9E&">F& D:A"&5&C9B">A&  & GHB<FIC9B">&0113J& HB<FIC9B">&0113K& HB<F&FLFE%&K&MFFNA&01134& HB<FIMFFN&0113O& KPO&"@CFAIMFFN&0113Q& RO&"@CFAIMFFN&01135& S9BF&0113T& & 56J&!DF<@FA&9?&<:#=>"&?@A>&<9BA#CF$&:B$&?EFU#FB<%&9?&<9BA#CD"@9B&9LFE&">F&D:A"&5&C9B">A6&&& !."#%"+(((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((4"05+( & !C:;;C9#">&+:AA&0113J&&&&&GHB<FIC9B">&0113J&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&HB<FIC9B">&0113K& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&HB<F&FLFE%&K&MFFNA&01134&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&HB<FIMFFN&0113O& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&KPO&"@CFAIMFFN&0113Q& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&RO&"@CFAIMFFN&01135& & V:;@W#"&&&&&&&&&&&&&&&&&&&&0113K&&&&&GHB<FIC9B">&0113J&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&HB<FIC9B">&0113K& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&HB<F&FLFE%&K&MFFNA&01134&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&HB<FIMFFN&0113O& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&KPO&"@CFAIMFFN&0113Q& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&RO&"@CFAIMFFN&01135& !:W;F?@A>& X:N:&+;:<N&,9$Y&&&&01134&&&&&GHB<FIC9B">&0113J&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&HB<FIC9B">&0113K& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&HB<F&FLFE%&K&MFFNA&01134&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&HB<FIMFFN&0113O& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&KPO&"@CFAIMFFN&0113Q& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&RO&"@CFAIMFFN&01135& & /;W:<9EF&8#B:&&&&&&&0113O&&&&GHB<FIC9B">&0113J&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&HB<FIC9B">&0113K& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&HB<F&FLFE%&K&MFFNA&01134&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&HB<FIMFFN&0113O& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&KPO&"@CFAIMFFN&0113Q& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&RO&"@CFAIMFFN&01135& & H">FE&8#B:&&&&&&&&&&&&&0113Q&&&&&GHB<FIC9B">&0113J&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&HB<FIC9B">&0113K& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&HB<F&FLFE%&K&MFFNA&01134&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&HB<FIMFFN&0113O& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&KPO&"@CFAIMFFN&0113Q& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&RO&"@CFAIMFFN&01135& &  4&  131
  !"#$%&'()&*+,&-&./!&-&0111211121113& & 5678&9:;#"&&&&&&&&&&&&&0113<&&&&&=>?@8AB;?"C&0113D&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&>?@8AB;?"C&0113E& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&>?@8&8F8:%&E&G887H&0113I&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&>?@8AG887&01134& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&EJ4&"KB8HAG887&0113L& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&M4&"KB8HAG887&0113<& & & ,#""C:;6"&9:;#"&&&&&0113N&&&&=>?@8AB;?"C&0113D&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&>?@8AB;?"C&0113E& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&>?@8&8F8:%&E&G887H&0113I&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&>?@8AG887&01134& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&EJ4&"KB8HAG887&0113L& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&M4&"KB8HAG887&0113<& & & .6K?O;G&9:;#"&&&&&0113P&&&&=>?@8AB;?"C&0113D&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&>?@8AB;?"C&0113E& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&>?@8&8F8:%&E&G887H&0113I&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&>?@8AG887&01134& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&EJ4&"KB8HAG887&0113L& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&M4&"KB8HAG887&0113<& & !"88QC86$&9:;#"&&0113R&&&&=>?@8AB;?"C&0113D&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&>?@8AB;?"C&0113E& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&>?@8&8F8:%&E&G887H&0113I&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&>?@8AG887&01134& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&EJ4&"KB8HAG887&0113L& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&M4&"KB8HAG887&0113<& & +:;;7&9:;#"&&&&&&&&&0113DS&&&&=>?@8AB;?"C&0113D&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&>?@8AB;?"C&0113E& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&>?@8&8F8:%&E&G887H&0113I&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&>?@8AG887&01134& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&EJ4&"KB8HAG887&0113L& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&M4&"KB8HAG887&0113<& & >"C8:&9:;#"&&&&&&&&&0113DD&&&&=>?@8AB;?"C&0113D&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&>?@8AB;?"C&0113E& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&>?@8&8F8:%&E&G887H&0113I&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&>?@8AG887&01134& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&EJ4&"KB8HAG887&0113L& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&M4&"KB8HAG887&0113<& & & & & &  4&  132
  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
  !"#$%&'()&*+,&-&./!&-&0111211121113& & 567789:8;&&&&&&&&&&&&&&0113<=&&&>?8@7ABC8"D&0113E&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?8@7ABC8"D&0113<& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?8@7&7F76%&<&G77HI&0113J&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?8@7AG77H&0113K& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&<LK&":B7IAG77H&0113=& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&MK&":B7IAG77H&0113N& O9C#8$76&&&&&&&&&&&&&&&0113<N&&&>?8@7ABC8"D&0113E&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?8@7ABC8"D&0113<& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?8@7&7F76%&<&G77HI&0113J&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?8@7AG77H&0113K& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&<LK&":B7IAG77H&0113=& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&MK&":B7IAG77H&0113N& & P#9Q@DC8&&&&&&&&&&&&&&&0113<4&&&>?8@7ABC8"D&0113E&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?8@7ABC8"D&0113<& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?8@7&7F76%&<&G77HI&0113J&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?8@7AG77H&0113K& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&<LK&":B7IAG77H&0113=& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&MK&":B7IAG77H&0113N& & RC99C@H&&&&&&&&&&&&&&&&&&&0113<S&&&>?8@7ABC8"D&0113E&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?8@7ABC8"D&0113<& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?8@7&7F76%&<&G77HI&0113J&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?8@7AG77H&0113K& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&<LK&":B7IAG77H&0113=& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&MK&":B7IAG77H&0113N& & &!D799T:ID& U!D6:BVW&R6QG8W& ,6QXW&Y#II79IW& !@Q99CVIW&?%I"76IW&& ,9QBIZ&&&&&&&&&&&&&&&&&&&0113<[&&&>?8@7ABC8"D&0113E&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?8@7ABC8"D&0113<& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?8@7&7F76%&<&G77HI&0113J&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?8@7AG77H&0113K& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&<LK&":B7IAG77H&0113=& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&MK&":B7IAG77H&0113N& ?"D76& & 11111111111111111&&&0113J\&&&&>?8@7ABC8"D&0113E&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?8@7ABC8"D&0113<& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?8@7&7F76%&<&G77HI&0113J&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?8@7AG77H&0113K& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&<LK&":B7IAG77H&0113=& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&MK&":B7IAG77H&0113N& & & &  4&  135
  !"#$%&'()&*+,&-&./!&-&0111211121113& 5"678& & 11111111111111111&&&&01139:&&&;5<=7>?@<"6&0113:&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&5<=7>?@<"6&0113A& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&5<=7&7B78%&A&C77DE&01139&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&5<=7>C77D&0113F& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&AGF&"H?7E>C77D&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&JF&"H?7E>C77D&0113K& & 5"678& & 11111111111111111&&&&&01139A&&;5<=7>?@<"6&0113:&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&5<=7>?@<"6&0113A& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&5<=7&7B78%&A&C77DE&01139&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&5<=7>C77D&0113F& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&AGF&"H?7E>C77D&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&JF&"H?7E>C77D&0113K& & & KLA&/B78MN7&?MEE&@O&=M#N6"& /0113:& OHE6&=@<E#?7$&M"&7M=6&?7MP& +0113A& ,01139& (0113F& Q0113I& R0113K&&& & & !"#$%&'()*(+&',-./$%&'(&0(1&-23$(4%,3( ( & & SLT&U@"MP&V@#N6"&OHE6& ;5<=7>?@<"6&0113:& =@<E#?W"H@<&O@8&"67&WME"&K& 5<=7>?@<"6&0113A& ?@<"6E& 5<=7&7B78%&A&C77DE&01139& 5<=7>C77D&0113F& AGF&"H?7E>C77D&0113I& JF&"H?7E>C77D&0113K& X@<7&0113Y& & SL:&!W7=H7E&@O&V@#N6"&OHE6&=@<E#?7$&M<$&O87Z#7<=%&@O&=@<E#?W"H@<&@B78&"67&WME"&K&?@<"6EL& !/"#%",(((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((5"67,( & !?MPP?@#"6&+MEE&&&&0113:&&;5<=7>?@<"6&0113:&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&5<=7>?@<"6&0113A& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&5<=7&7B78%&A&C77DE&01139&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&5<=7>C77D&0113F& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&AGF&"H?7E>C77D&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&JF&"H?7E>C77D&0113K& & &  4&  136
  !"#$%&'()&*+,&-&./!&-&0111211121113& & !56&+677&&&&&&&&&&&&&&&&&&&&01138&&9:;<5=>?;"@&0113A&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&:;<5=>?;"@&01138& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&:;<5&5B5C%&8&D55E7&0113F&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&:;<5=D55E&0113G& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&8HG&"I>57=D55E&0113J& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&KG&"I>57=D55E&0113L& & !6MN5OI7@& P6E6&+N6<E&,?$Q&&&&&&0113F&&&9:;<5=>?;"@&0113A&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&:;<5=>?;"@&01138& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&:;<5&5B5C%&8&D55E7&0113F&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&:;<5=D55E&0113G& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&8HG&"I>57=D55E&0113J& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&KG&"I>57=D55E&0113L& & ,6;;5$&/NM6<?C5& R#;6&&&&&&&&&&&&&&&&&&&&&&&&&&0113G&&&&9:;<5=>?;"@&0113A&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&:;<5=>?;"@&01138& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&:;<5&5B5C%&8&D55E7&0113F&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&:;<5=D55E&0113G& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&8HG&"I>57=D55E&0113J& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&KG&"I>57=D55E&0113L& :"@5C&,6;;5$&& R#;6&&&&&&&&&&&&&&&&&&&&&&&&&&0113J&&&9:;<5=>?;"@&0113A&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&:;<5=>?;"@&01138& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&:;<5&5B5C%&8&D55E7&0113F&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&:;<5=D55E&0113G& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&8HG&"I>57=D55E&0113J& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&KG&"I>57=D55E&0113L& & SC57@&?C&SC?T5;& /NM6<?C5&R#;6&&&&&&&0113L&&&&&9:;<5=>?;"@&0113A&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&:;<5=>?;"@&01138& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&:;<5&5B5C%&8&D55E7&0113F&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&:;<5=D55E&0113G& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&8HG&"I>57=D55E&0113J& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&KG&"I>57=D55E&0113L& SC57@&?C&SC?T5;& :"@5C&R#;6&&&&&&&&&&&&&&0113U&&&9:;<5=>?;"@&0113A&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&:;<5=>?;"@&01138& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&:;<5&5B5C%&8&D55E7&0113F&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&:;<5=D55E&0113G& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&8HG&"I>57=D55E&0113J& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&KG&"I>57=D55E&0113L& & & & &  4&  137
  !"#$%&'()&*+,&-&./!&-&0111211121113& & 6789:&;7&67;<8=& >?@AB#"&&&&&&&&&&&&&&&&&&&&0113C&&&&DE=F8GH;=":&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&E=F8GH;=":&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&E=F8&8J87%&I&K88L9&0113M&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&E=F8GK88L&0113N& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&ION&"AH89GK88L&0113P& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&QN&"AH89GK88L&0113R& & S?7@A=&&&&&&&&&&&&&&&&&&&&&0113T&&&&&DE=F8GH;=":&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&E=F8GH;=":&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&E=F8&8J87%&I&K88L9&0113M&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&E=F8GK88L&0113N& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&ION&"AH89GK88L&0113P& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&QN&"AH89GK88L&0113R& & !K;7$UA9:&&&&&&&&&&&&&&011345&&&DE=F8GH;=":&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&E=F8GH;=":&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&E=F8&8J87%&I&K88L9&0113M&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&E=F8GK88L&0113N& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&ION&"AH89GK88L&0113P& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&QN&"AH89GK88L&0113R& & E7?=V8&.;#V:%&&&&011344&&&DE=F8GH;=":&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&E=F8GH;=":&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&E=F8&8J87%&I&K88L9&0113M&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&E=F8GK88L&0113N& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&ION&"AH89GK88L&0113P& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&QN&"AH89GK88L&0113R& & ,;$&&&&&&&&&&&&&&&&&&&&&&&&&&&01134I&&&DE=F8GH;=":&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&E=F8GH;=":&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&E=F8&8J87%&I&K88L9&0113M&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&E=F8GK88L&0113N& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&ION&"AH89GK88L&0113P& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&QN&"AH89GK88L&0113R& & !:?7L&&&&&&&&&&&&&&&&&&&&&&&01134M&&&DE=F8GH;=":&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&E=F8GH;=":&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&E=F8&8J87%&I&K88L9&0113M&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&E=F8GK88L&0113N& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&ION&"AH89GK88L&0113P& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&QN&"AH89GK88L&0113R& & & & & & &  45&  138
  !"#$%&'()&*+,&-&./!&-&0111211121113& & (56789:&&&&&&&&&&&&&&&&&&&&01134;&&&<=>?@AB5>":&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@AB5>":&0113C& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@&@D@E%&C&F@@G9&0113H&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@AF@@G&0113;& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&CI;&"8B@9AF@@G&0113J& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&K;&"8B@9AF@@G&0113L& & M8>6?5$&&&&&&&&&&&&&&&&&&&01134J&&&<=>?@AB5>":&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@AB5>":&0113C& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@&@D@E%&C&F@@G9&0113H&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@AF@@G&0113;& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&CI;&"8B@9AF@@G&0113J& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&K;&"8B@9AF@@G&0113L& MNG@&OE5#"&&&&&&&&&&&&&&01134L&&<=>?@AB5>":&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@AB5>":&0113C& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@&@D@E%&C&F@@G9&0113H&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@AF@@G&0113;& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&CI;&"8B@9AF@@G&0113J& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&K;&"8B@9AF@@G&0113L& & .N8>P5F&OE5#"&&&&&01134Q&&<=>?@AB5>":&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@AB5>":&0113C& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@&@D@E%&C&F@@G9&0113H&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@AF@@G&0113;& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&CI;&"8B@9AF@@G&0113J& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&K;&"8B@9AF@@G&0113L& & ,#"":E5N"&OE5#"&&&&01134R&&&<=>?@AB5>":&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@AB5>":&0113C& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@&@D@E%&C&F@@G9&0113H&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@AF@@G&0113;& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&CI;&"8B@9AF@@G&0113J& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&K;&"8B@9AF@@G&0113L& & !"@@S:@N$&OE5#"&&&&&01134T&<=>?@AB5>":&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@AB5>":&0113C& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@&@D@E%&C&F@@G9&0113H&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@AF@@G&0113;& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&CI;&"8B@9AF@@G&0113J& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&K;&"8B@9AF@@G&0113L& & +E55G&OE5#"&&&&&&&&&&&0113CU&&&<=>?@AB5>":&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@AB5>":&0113C& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@&@D@E%&C&F@@G9&0113H&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&=>?@AF@@G&0113;& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&CI;&"8B@9AF@@G&0113J& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&K;&"8B@9AF@@G&0113L& &  44&  139
  !"#$%&'()&*+,&-&./!&-&0111211121113& 6"789&:9;#"&&&&&&&&&&011354&&&&<6=>8?@;="7&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8?@;="7&01135& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8&8A89%&5&B88CD&0113E&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8?B88C&0113F& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&5GF&"H@8D?B88C&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&JF&"H@8D?B88C&0113K& /LL&!M8>H8D& ;N&!OL@;=&&&&&&&&&&&&&&&011355&&&<6=>8?@;="7&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8?@;="7&01135& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8&8A89%&5&B88CD&0113E&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8?B88C&0113F& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&5GF&"H@8D?B88C&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&JF&"H@8D?B88C&0113K& & P;CO=88&&&&&&&&&&&&&&&&01135E&&&&<6=>8?@;="7&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8?@;="7&01135& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8&8A89%&5&B88CD&0113E&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8?B88C&0113F& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&5GF&"H@8D?B88C&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&JF&"H@8D?B88C&0113K& & /9>"H>&,7O9&&&&&&&&&&&&&&01135F&&<6=>8?@;="7&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8?@;="7&01135& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8&8A89%&5&B88CD&0113E&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8?B88C&0113F& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&5GF&"H@8D?B88C&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&JF&"H@8D?B88C&0113K& & Q;=CNHD7&&&&&&&&&&&&&&&&01135I&&&<6=>8?@;="7&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8?@;="7&01135& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8&8A89%&5&B88CD&0113E&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8?B88C&0113F& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&5GF&"H@8D?B88C&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&JF&"H@8D?B88C&0113K& & QO7H&QO7H&&&&&&&&&&&&&&01135K&&&&<6=>8?@;="7&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8?@;="7&01135& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8&8A89%&5&B88CD&0113E&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8?B88C&0113F& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&5GF&"H@8D?B88C&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&JF&"H@8D?B88C&0113K& R98D7&;9&R9;S8=& !;L8&&&&&&&&&&&&&&&&&&&&&&&&&&01135T&&&&<6=>8?@;="7&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8?@;="7&01135& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8&8A89%&5&B88CD&0113E&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8?B88C&0113F& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&5GF&"H@8D?B88C&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&JF&"H@8D?B88C&0113K& &  45&  140
  !"#$%&'()&*+,&-&./!&-&0111211121113& 67889:;&&&&&&&&&&&&&&&&&&0113<=&&&>?:@7ABC:"D&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7ABC:"D&0113<& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7&7E78%&<&F77GH&01135&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7AF77G&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&<JI&"9B7HAF77G&0113K& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&LI&"9B7HAF77G&0113M& & NO@G787P&&&&&&&&&&&&&&&0113<Q&&&&>?:@7ABC:"D&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7ABC:"D&0113<& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7&7E78%&<&F77GH&01135&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7AF77G&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&<JI&"9B7HAF77G&0113K& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&LI&"9B7HAF77G&0113M& & R78@D&&&&&&&&&&&&&&&&&&&&&&01135S&&&&>?:@7ABC:"D&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7ABC:"D&0113<& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7&7E78%&<&F77GH&01135&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7AF77G&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&<JI&"9B7HAF77G&0113K& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&LI&"9B7HAF77G&0113M& T87HD&C8&,O::7$& !O8$9:7&&&&&&&&&&&&&&&&&&&011354&&&>?:@7ABC:"D&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7ABC:"D&0113<& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7&7E78%&<&F77GH&01135&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7AF77G&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&<JI&"9B7HAF77G&0113K& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&LI&"9B7HAF77G&0113M& & +OHO&&&&&&&&&&&&&&&&&&&&&&&01135<&&&&>?:@7ABC:"D&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7ABC:"D&0113<& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7&7E78%&<&F77GH&01135&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7AF77G&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&<JI&"9B7HAF77G&0113K& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&LI&"9B7HAF77G&0113M& & !:OUU78&&&&&&&&&&&&&&&011355&&&&&>?:@7ABC:"D&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7ABC:"D&0113<& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7&7E78%&<&F77GH&01135&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7AF77G&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&<JI&"9B7HAF77G&0113K& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&LI&"9B7HAF77G&0113M& & TPC#:$78&&&&&&&&&&&&&&01135I&&&&>?:@7ABC:"D&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7ABC:"D&0113<& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7&7E78%&<&F77GH&01135&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&?:@7AF77G&0113I& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&<JI&"9B7HAF77G&0113K& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&LI&"9B7HAF77G&0113M& &  45&  141
  !"#$%&'()&*+,&-&./!&-&0111211121113& 6789:&;7&67;<8=& >?@AB?A&&&&&&&&&&&&&&&&&&&&0113CD&&EF=G8HI;=":&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&F=G8HI;=":&0113J& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&F=G8&8K87%&J&L88M9&0113C&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&F=G8HL88M&01135& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&JN5&"?I89HL88M&0113D& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&O5&"?I89HL88M&0113P& & 6789:&;7&67;<8=& Q;@@;GM&&&&&&&&&&&&&&&&&&&0113CP&&&EF=G8HI;=":&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&F=G8HI;=":&0113J& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&F=G8&8K87%&J&L88M9&0113C&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&F=G8HL88M&01135& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&JN5&"?I89HL88M&0113D& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&O5&"?I89HL88M&0113P& & Q7;G8998$&6?9:& R6?9:&!"?GM9S&6A9"N6;;$& 6?9:&!A=$L?G:89S& 67;<8=&+A""878$& 6?9:S&8"GTU&&&&&&&&&&&&&&&&0113CV&&&EF=G8HI;=":&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&F=G8HI;=":&0113J& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&F=G8&8K87%&J&L88M9&0113C&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&F=G8HL88M&01135& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&JN5&"?I89HL88M&0113D& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&O5&"?I89HL88M&0113P& !:8@@W?9:& R!:7?IBS&Q7AL=S& ,7AXS&Y#998@9S& !GA@@;B9S&F%9"879S&& ,@AI9U&&&&&&&&&&&&&&&&&0113CZ&&&EF=G8HI;=":&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&F=G8HI;=":&0113J& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&F=G8&8K87%&J&L88M9&0113C&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&F=G8HL88M&01135& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&JN5&"?I89HL88M&0113D& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&O5&"?I89HL88M&0113P& & F":87& & 11111111111111111&&&&&0113C[&&EF=G8HI;=":&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&F=G8HI;=":&0113J& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&F=G8&8K87%&J&L88M9&0113C&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&F=G8HL88M&01135& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&JN5&"?I89HL88M&0113D& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&O5&"?I89HL88M&0113P& & & & &  45&  142
  !"#$%&'()&*+,&-&./!&-&0111211121113& 6"789& & 11111111111111111&&&&&0113:;&&<6=>8?@A="7&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8?@A="7&0113B& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8&8C89%&B&D88EF&0113G&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8?D88E&0113:& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&BH:&"I@8F?D88E&01135& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&J:&"I@8F?D88E&0113K& & 6"789& & 11111111111111111&&&&&0113:4&&<6=>8?@A="7&01134&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8?@A="7&0113B& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8&8C89%&B&D88EF&0113G&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&6=>8?D88E&0113:& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&BH:&"I@8F?D88E&01135& &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&J:&"I@8F?D88E&0113K& & & LMB&/C89NO8&@NFF&AP& /01134& QA#O7"&PIF7&>A=F#@8$& +0113B& N"&8N>7&@8NR& ,0113G& (0113:& S01135& T0113K&&& & &  &  45&  143
  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
  !"#$%&'()&*+,&-&./!&-&0111211121113& & & 4678&/99#:;&'9<=>?&&  & 4578&+=$%&O?NPB"& &  & @?AA&"B:9&CD8E888&&&&&&&&&&&&&&&&01134& CD8E888FCGHEHHH&&&&&&&&&&&&&&&&&&0113D& CI8E888FCJHEHHH&&&&&&&&&&&&&&&&&&0113G& CK8E888FC6HEHHH&&&&&&&&&&&&&&&&&&0113I& L=M?&"B:9&C58E888&&&&&&&&&&&&&&0113J& (?<;N9?&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&0113H& & & 0111211121113;QA&&=M&&0111211121113RP& & (?<;N9?&0113H& &  &  &  45&  146
  
  Appendix O: Questionnaire Script  Questionnaire Script ! I would like to thank you for your time and participation in this study. Your participation is entirely voluntary and you may withdraw at any time. Information you provide will be used solely for the purposes of the study and will be kept confidential at all times. No identifying information will be published at any time. The questions asked in this interview will help us determine your exposure to methylmercury, a common contaminant in fish. As such, questions will primarily focus on your fishing habits and fish consumption patterns. We are also interested in other sources of mercury you may be exposed to and therefore some questions will focus on your occupation and hobbies. The questionnaire contains 6 sections (A-F) and a minimum of 22 questions. The entire interview should take between 20 and 30 minutes. Before the start of each question, I will inform you of the instructions. Feel free to ask any questions before or after the questionnaire, however I should mention that my responses to questions during the interview might be limited. The reason for this is to ensure the same interview is given to each study participant. If you are unsure of what I am asking in the question, please answer to the best of your understanding. I will be able to repeat questions as many times as you need but will not be able to dramatically change the wording of any of the questions. Before we begin with the interview, do you have any questions about the study, the consent form or any other questions in general? Section A: Demographics The first section, Section A, will ask about your personal information. There are 4 questions in this section and it should take no more than 2 minutes to complete. Are you ready to proceed? Question 1.0: For confirmation purposes, is your name __________________? Question 2.0: For confirmation purposes, is your address ________________ ? For confirmation purposes, is this the phone number you would like us to use for any future communication? Question 3.0: For confirmation purposes, are you male or female? Question 4.0: What is your year and month of birth? This concludes the questions for this section.  147
  Section B: Recreational Fishing Information The second section, Section B, will examine your recreational fishing habits. There is only one question in this section that should take no more than one minute to complete. Are you ready to proceed? Question 5.0 Fishing seasons vary for each fisherman. We would like to determine the months of the year in which you fish the most. Please note that fishing only refers to the catching of fish and does not include crabbing and the collection or gathering of other types of shellfish. Therefore, to the best of your memory, how many times on average did you go fishing in May 2009? June 2009? July 2009? August 2009? September 2009? October 2009? November 2009? December 2009? January 2010? February 2010? March 2010? April 2010? This concludes the questions for this section. Section C: Caught Fish Consumption The third section, Section C, will examine your recreational fish consumption patterns. In general, we would like to know what types of fish you are both catching and eating. A recreationally caught fish is one that you, a family member, friend or other person has personally caught. They also include caught fish received as a gift. In general, a caught fish is one not purchased by you or another person. Please note that we are not interested in fish that you catch and release. We are only interested in the fish that you catch and then eat. Before proceeding, do you have any questions as to what defines a recreationally caught fish? Please consider only the past 6 months when answering these questions. There are 3 questions in this section. This section should take about 5 minutes to complete. Are you ready to proceed? Question 6.0 In the past 6 months, how often, on average, do you eat fish that is caught recreationally: less than once/month, once/month, once every 2 weeks, once/week, 2-4 times/week or more than 4 times/week? Question 6.1 We would like to know which species of fish you catch AND eat. I will go through a list of 29 different fish species. As we go through the list, please tell me which species you eat and how often you eat that type of fish. Understandably, the types of fish and how often you eat them will vary depending on a number of factors, including the season. When telling me how often you eat each type of fish, try to provide an average amount over the past 6 months. For example, if you tell me that you have caught and eaten salmon in the past 6 months, I will ask you whether you ate caught salmon, on average, less than once/month, once/month, once every 2 weeks, once/week, 2-4 times/week or more than 4 times/week.  148
  When Trout arises, the interviewer will ask, “Do you catch and eat trout?” If yes, the interviewer will go through the different trout species. If no, move on to the next species. Following the list, the interviewer will ask, “Are there any other species I have not mentioned that you catch and eat?” Question 6.2 For this question, please refer to the document entitled ‘Estimating Your Fish Consumption’. The purpose of this question is to determine the weight of fish you typically eat when you eat caught fish. To help you provide an answer, pictures of fish portion sizes and their respective weight have been attached. Since you may be more familiar with certain cuts of fish more than others, the pictures have been divided into 2 different categories: thick cuts of fish and thin cuts of fish. These cuts of fish have been placed onto a standard-sized dinner plate (101/4 inches) to help you recall how much you usually eat. Thick cuts of fish refer to large fillets and steaks such as those from Salmon, Halibut and Tuna. These types of cuts tend to come from larger fish. Thin cuts of fish refer to small fillets such as those that come from Trout. Before proceeding, please tell me which types of cuts are you most familiar with? If thick: Please refer to Page 2 of the guide If thin: Please refer to Page 3 of the guide There are 6 total categories (A-F) with 2 pictures in each to provide you with two different perspectives of the fish. Please look through photos A-F and tell me which one letter best represents your typical portion size of caught fish. This concludes the questions for this section. Section D: Bought Fish Consumption The fourth section, Section D, will examine your bought fish consumption patterns. In general, we would like to know what types of fish you are buying and eating. A bought fish is any fish purchased at a store, market or restaurant. This includes any canned products, such as canned Tuna, Salmon or Sardines as well as sushi and sashimi. Before proceeding, do you have any questions as to what defines a bought fish? Please consider the past 6 months when answering these questions. This section contains 3 questions and should take about 5 minutes. Are you ready to proceed? Question 7.0  In the past 6 months, how often, on average, do you eat bought fish: less than once/month, once/month, once every 2 weeks, once/week, 2-4 times/week or more than 4 times/week?  Question 7.1  We would like to know which species of fish you buy AND eat. I will go through a list of 35 different species. Please tell me which species you eat and as you do so, whether you eat it, on average, less than once/month,  149
  once/month, once every 2 weeks, once/week, 2-4 times/week or more than 4 times/week. Similar to the previous section, please consider only the past 6 months when answering this question. When Trout arises, the interviewer will ask, “Do you catch and eat trout?” If yes, the interviewer will go through the different trout species. If no, move on to the next species. Following the list, the interviewer will ask, “Are there any other species I have not mentioned that you buy and eat?” Question 7.2  For this question, please refer back to the document entitled ‘Estimating Your Fish Consumption’. Once again, we would like to know the weight of fish you typically eat when you eat bought fish. After selecting the cuts of fish that are most familiar to you, please tell me which picture best represents the portion size of bought fish you would usually eat.  This concludes the questions for this section. Section E: Additional Exposure Information The fifth section, Section E, examines other exposure to mercury you may have had. It contains 9 questions and should only take about 5 minutes to complete. Are you ready to proceed? Question 8.0 What is your occupation? Question 9.0 For this question, I am going to list a number of job locations. Please answer yes or no as to whether you work, or have worked in the past year, in any of these places: interviewer will go through list. Question 10.0 Do you currently have dental amalgams (i.e. silver fillings) applied to your teeth? If yes, the interviewer will proceed to question 15.1. If no, the interviewer will proceed to question 16.0. Question 10.1 Have you had any of them removed in the past 3 months? Question 11.0 Do you do any painting as a hobby, part of your job or in your free time? If yes, the interviewer will proceed to question 16.1. If no, the interviewer will proceed to question 12.0. Question 11.1 To the best of your knowledge, do you use paints that contain mercury? Question 12.0 Do you take any nutritional and/or therapeutic medications or supplements that, to the best of your knowledge, contain mercury?  150
  Question 13.0 To the best of your knowledge, are you exposed to mercury in any form throughout an average day that I have not covered? If yes, the interviewer will proceed to question 18.1. Question 13.1 Please describe these exposures including where the exposure comes from, as well as how long you are exposed each day. This concludes the questions for this section. Section F: Additional Research Questions This final section contains 5 questions and should take no longer than 4 minutes. While some of these questions may appear to be unrelated to fish consumption, collecting information on the following questions will help us examine the other possible and less obvious relationships between eating fish and mercury exposure. Are you ready to proceed? Question 14.0: Do you currently hold a Provincial Freshwater license only or a Provincial Freshwater license and a Federal Saltwater/Tidal Water license as well? Question 15.0: What country were you born in? Question 16.0: What country were your parents born in? Question 17.0: For this question, I am going to read 5 different ranges of total annual income. Note that total income refers to all sources of income, before taxes, including salary, wage, pension, employment insurance, RRSPs, investment income, benefits, other money sources, etc. Please listen to all of the following ranges and tell me which one best represents your total annual income. Feel free to interrupt me once I pass your range to provide your answer. Range 1, less than $20,000/year. Range 2, between $20,000 and $39,999/year. Range 3, between $40,000 and $59,999/year. Range 4, between $60,000 and $79,999/year. Range 5, more than $80,000/year. Please tell me if you’d like me to repeat them. Question 18.0: What is your body weight? You can provide it in pounds or kilograms. This concludes the questionnaire. The answers you have provided will help us to further investigate mercury exposures in BC recreational anglers. While the questionnaire has provided valuable information on how you may be exposed, finding out how much mercury is present within you is also important. This information can help us determine whether the types and amounts of fish you are eating are contributing to your exposure. Therefore, the next step in this study is to provide a blood sample. Please take the provided requisition form to the nearest LifeLabs location to have the sample taken. Following completion of the study, you will be mailed your gift certificate as well as the personal results of your blood sample with an explanation of what they mean. Once again, we sincerely appreciate your help in this study. Do you have any questions?  
  151
  Appendix P: Subject Response Letter - Blood-Mercury < 10 µg/L  ! Dear Mr. or Mrs., Enclosed is your personal blood-mercury result, a copy of the fully signed consent form and your gift certificate. There were approximately 200 participants who completed the telephone questionnaire and provided a blood sample between June and November 2010. Mercury is a naturally occurring element; exposure to some amount of mercury is essentially universal. The results of the recent Canada Health Measures Survey (CHMS) conducted by Statistics Canada showed 88% of Canadians between the ages of 6 to 79 have measurable concentrations of mercury in their blood. Food is the most important source of mercury exposure for the general Canadian population. Fish contributes most of the exposure from diet. Your personal blood-mercury level was: ____ µg/L According to the CHMS, 95% of the general population has a blood-mercury level below 4.7µg/L. However, many of the people surveyed ate little or no fish on a regular basis. One would expect to find higher blood mercury levels in people who eat fish on a regular basis. Although at very high concentrations mercury can have toxic effects, many studies have shown that health benefits, including lower risk of cardiovascular disease, are associated with people who eat fish once or more per week. For children and women of childbearing age, Health Canada recommends a repeat bloodmercury test in 6 months and a review of dietary sources of mercury when blood levels exceed 8µg/L. For other Canadians, this is recommended at 20 µg/L. It should be noted that both of these levels are well below the level at which toxic effects from mercury would be expected. One way of obtaining the benefits of fish consumption while reducing mercury intake is to select fish species with low mercury concentrations for frequent consumption and to consume fish with moderate mercury concentrations less frequently. If you are interested, one website that provides information on mercury concentrations in different fish species is Health Link BC: http://www.healthlinkbc.ca/healthfiles/hfile68m.stm If you would like us to forward your blood mercury results to your family physician, please forward us the appropriate contact information.  Please Turn Over  152
  Once again, we would like to thank you for your participation in this valuable study and for your patience in waiting for your results. In the coming months, we will be sending you a brief summary of the study results so you can see how you compare with the other participants. If you have any questions, comments or concerns, please feel free to contact us at: David Kodama University of British Columbia School of Environmental Health 3rd Floor - 2206 East Mall Vancouver, BC V6T 1Z3 604-827-3517 dkodama@interchange.ubc.ca Sincerely, ! ! ! """"""""""""""""""""""""""""""""""""""""""""""! Ray Copes, MD, Clinical Professor, UBC ! ! ! """"""""""""""""""""""""""""""""""""""""""""! David Kodama, MSc Candidate, UBC  
  153
  Appendix Q: Subject Response Letter - Blood-Mercury ≥ 10 µg/L  ! Dear Mr. or Mrs., Enclosed is your personal blood-mercury result, a copy of the fully signed consent form and your gift certificate. There were approximately 200 participants who completed the telephone questionnaire and provided a blood sample between June and November 2010. Mercury is a naturally occurring element; exposure to some amount of mercury is essentially universal. The results of the recent Canada Health Measures Survey (CHMS) conducted by Statistics Canada showed 88% of Canadians between the ages of 6 to 79 have measurable concentrations of mercury in their blood. Food is the most important source of mercury exposure for the general Canadian population. Fish contributes most of the exposure from diet. Your personal blood-mercury level was: ____ µg/L According to the CHMS, 95% of the general population has a blood-mercury level below 4.7µg/L. However, many of the people surveyed ate little or no fish on a regular basis. One would expect to find higher blood-mercury levels in people who eat fish on a regular basis. Although at very high concentrations mercury can have toxic effects, many studies have shown that health benefits, including lower risk of cardiovascular disease, are associated with people who eat fish once or more per week. For children and women of childbearing age, Health Canada recommends a repeat bloodmercury test in 6 months and a review of dietary sources of mercury when blood levels exceed 8µg/L. For other Canadians, this is recommended at 20 µg/L. It should be noted that both of these levels are well below the level at which toxic effects from mercury would be expected. While your blood-mercury result remains below the level at which toxic effects from mercury are expected, it is significantly greater than what is seen in the general population. You indicated through the questionnaire that you had consumed the following fish species over the past six months: Species A B C etc.  Caught Fish Frequency of Consumption X Y Z etc.  Species D E F etc.  Bought Fish Frequency of Consumption Y X Z etc.  Of these types of fish, A, D, F, etc. have been shown to contain moderate amounts of mercury (the remaining types of fish generally contain minimal amounts of mercury). You also indicated that your typical fish portion size when eating “caught” fish is approximately ___ g and ___ g for “bought” fish.  Please Turn Over  154
  When examining the risk of mercury exposure from fish, we generally consider three factors: 1) the type of fish that is eaten, 2) how often the fish is eaten and 3) how much of the fish is eaten. Of the fish you eat, it is likely that your consumption of A and E at X times per week, are the largest contributors to your overall mercury exposure. One way of obtaining the benefits of fish consumption while reducing mercury intake is to select fish species with low mercury concentrations for frequent consumption and to consume fish with moderate mercury concentrations less frequently and/or in smaller portions. If you are interested, one website that provides information on mercury concentrations in different fish species is Health Link BC: http://www.healthlinkbc.ca/healthfiles/hfile68m.stm If you would like us to forward your blood-mercury results to your family physician, please send us the appropriate contact information. Once again, we would like to thank you for your participation in this valuable study and for your patience in waiting for your results. In the coming months, we will be sending you a brief summary of the study results so you can see how you compare with the other participants. If you have any questions, comments or concerns, please feel free to contact us at: David Kodama University of British Columbia School of Environmental Health 3rd Floor - 2206 East Mall Vancouver, BC V6T 1Z3 604-827-3517 dkodama@interchange.ubc.ca Sincerely, ! ! ! """"""""""""""""""""""""""""""""""""""""""""""! Ray Copes, MD, Clinical Professor, UBC ! ! ! """"""""""""""""""""""""""""""""""""""""""""! David Kodama, MSc Candidate, UBC  155
  

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.24.1-0102581/manifest

Comment

Related Items