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Bioindication of atmospheric heavy metals in the lower Fraser Valley, B.C., Canada Pott, Ute 1995

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BIOINDICATION OF ATMOSPHERIC HEAVY METALS IN THE LOWER FRASER VALLEY, B.C., CANADA. by UTE POTT A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES (Department of Botany) We accept thils thesk as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA April 1995 © Ute Pott, 1995 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department The University of British Columbia Vancouver, Canada Date £<T- 9- /??S DE-6 (2/88) ABSTRACT The atmospheric heavy metal content of the Fraser Valley, B.C., Canada was assessed for 1993 by analyzing lead, cadmium, chromium, nickel, zinc, and manganese content in 62 samples of the common woodland moss Isothecium stoloniferum Brid. Lead, cadmium, nickel and zinc showed a correlated regional distribution with high values in the western more urbanized areas and lower values in the rural eastern areas. Chromium and manganese exhibited a less distinct distribution pattern. Highest values were recorded for the North Shore Mountains relating to increased precipitation and pollutant transport by the local wind pattern from industrial areas in the Port Moody, Burnaby area, where metal readings reached another maximum. Relationships of these findings to population density, land use, traffic and industrial activity were investigated. Historical changes of metal levels in the ambient air of the study area since the early 1960s were examined through analysis of moss specimens from the U.B.C. herbarium. Metal pollution patterns were established for the periods 1960 - 1966 and 1975 - 1980. In addition, changes in metal levels in moss samples from three sites with a continuous collection record since the 1960's are described. A general decline in atmospheric levels for lead, cadmium, chromium, nickel, and zinc was found. The observed decrease reflected the reduction of heavy industries in the area, abandonment of leaded gasoline and the change from oil to gas and elecuicity for space heating. Reduction in atmospheric metals, as determined by the moss method, reflected the general decline in particulate .emission, as determined by the GVRD direct air sampling program. Manganese levels, in contrast, have increased since the 1960s, which might be n attributed to the addition of Methylcyclopentadienyl manganese tricarbonyl (MMT) to gasoline, replacing the leaded antiknock additives. Comparisons were made to recent metal levels and historical changes reported from European 'moss method' studies. The potential of the 'moss method' to be used for general air quality assessments was investigated, by comparison to direct air quality measurements of various pollutants and a general air quality index. iii TABLE OF CONTENTS ABSTRACT ii LIST OF TABLES viii LIST OF FIGURES x ABBREVIATIONS xiii ACKNOWLEDGEMENTS xiv CHAPTER 1: INTRODUCTION 1.1 G E N E R A L INTRODUCTION 1 1.2 L I T E R A T U R E R E V I E W : BIOINDICATION 2 1.2.1 General Bioindication 2 1.2.2 Bioindicator Organisms 3 1.1.3 The "Moss Method" 5 1.2.4 Ion Uptake - Basic Concepts of the 'Moss Method' 6 1.2.4.1 Uptake from Atmospheric Sources 7 1.2.4.2 Ion Accumulation and Cation Exchange 8 1.2.4.3 Element Content in different Moss Parts 9 1.2.4.4 Interspecies Variation 11 1.2.4.5 Effect of Precipitation, Canopy arid Exposure 11 1.3 L I T E R A T U R E R E V I E W : H E A V Y M E T A L S 13 1.3.1 Terminology 13 1.3.2 Heavy Metals in the Biosphere 14 1.3.3 Heavy Metals in the Atmosphere 14 1.3.4 Sources and Health Effects of Heavy Metals 17 1.3.4.1 Lead 17 1.3.4.2 Cadmium 19 1.3.4.3 Chromium 2 0 1.3.4.4 Nickel 2 2 1.3.4.5 Zinc 2 4 1.3.4.6 Manganese 2 5 1.4 T H E F R A S E R V A L L E Y - DESCRIPTION OF T H E S T U D Y A R E A 2 8 1.4.1 Location 28 1.4.2 Climate 28 1.4.3 Wind Patterns and Air Movement 3 0 iv 1.4.4 Population 33 1.4.5 Heavy Metals in the Fraser Valley '. 33 1.4.5.1 Point Sources 34 1.4.5.2 Area Sources 36 1.4.5.3 Mobile Sources 36 1.5 OBJECTIVES 38 C H A P T E R 2: M A T E R I A L S A N D M E T H O D S 2.1 Moss SPECIES 39 2.2 FRASER V A L L E Y 1993 C O L L E C T I O N 40 2.2.1 Sample Collection 40 2.2.2 Sample Processing 40 2.2.3 Digestion and Analysis... 42 2.2.4 Data processing: 43 2.2.5 Geographical Representation and Statistical analysis 43 2.2.6 The Metal Index 44 2.2.7 Relation to Natural Factors 44 2.2.8 Relation to Anthropogenic Factors 46 2.3 H E R B A R I U M C O L L E C T I O N 48 2.3.1 Sample collection 48 2.3.2 Sample Processing, Digestion and Analysis 48 2.3.3 Data Processing 50 2.3.4 Geographical Representation and Statistical Analysis 50 2.4 Q U A L I T Y C O N T R O L A N D ERROR ASSESSMENT 51 2.4.1 Accuracy 51 2.4.2 Variation among Subsamples 51 2.4.3 Precision 52 2.5 COMPARISON OF T H E Moss M E T H O D TO DIRECT AIR M E A S U R E M E N T S 53 C H A P T E R 3: R E S U L T S A N D D I S C U S S I O N : Q U A L I T Y C O N T R O L A N D E R R O R A S S E S S M E N T 3.1 A C C U R A C Y 54 3.2 VARIATION A M O N G SUBSAMPLES 55 3.3 PRECISION 57 3.4 CONCLUSION .59 v C H A P T E R 4: R E S U L T S A N D DISCUSSION: F R A S E R V A L L E Y C O L L E C T I O N 1993 4.1 REGIONAL DISTRIBUTION OF METAL CONTENT IN MOSSES IN 1993 60 4.1.1 Lead 60 4.1.2 Cadmium 63 4.1.3 Chromium 65 4.1.4 Nickel 67 4.1.5 Zinc 69 4.1.6 Manganese 71 4.2 METAL INDEX 73 4.3 RELATION TO NATURAL FACTORS : 76 4.3.1 Precipitation 76 4.3.2 Elevation 78 4.3.3 Wind Pattern 79 4.4 RELATION TO ANTHROPOGENIC FACTORS 81 4.4.1 Population 81 4.4.2 Landuse , 82 4.4.3 Industrial Activity 83 4.4.4 Traffic - Mobile Sources 88 4.5 LITERATURE COMPARISON 89 4.5 FRASER VALLEY CONCLUSION 94 C H A P T E R 5: R E S U L T S A N D DISCUSSION: H E R B A R I U M C O L L E C T I O N 5.1 REGIONAL DISTRIBUTION OF HEAVY METALS IN HERBARIUM SAMPLES 95 5.1.1 Regional distribution of Heavy Metals in 1960 - 1966 95 5.1.2 Regional Distribution of Heavy Metals in 1975 - 1980 100 5.2 CHANGES OVER TIME 104 5.2.1 Comparison of the Three Collections Periods (1960 -66, 1975 - 80, 1993)... 104 5.2.2 Site - Time Line Analysis ; 108 5.4 FACTORS INFLUENCING HISTORICAL CHANGES OF METAL CONCENTRATION IN ISOTHECIUM STOLONIFERUM 113 5.4.1 Point Sources - Changes in Industrial Activity 113 5.4.2 Area Sources - Changes in Space Heating Fuels 114 5.4.3 Mobile Sources - Changes in Gasoline Composition 117 5.5 LITERATURE COMPARISON .120 5.6 CONCLUSION 124 vi C H A P T E R 6: ' T H E V A L U E O F T H E 'MOSS M E T H O D ' 6.1 T H E 'MOSS M E T H O D ' C O M P A R E D TO D I R E C T M E T A L MEASUREMENTS 127 6.2 T H E 'MOSS M E T H O D ' AS A G E N E R A L PARTICULATE POLLUTION INDICATOR 127 6.3 T H E 'MOSS M E T H O D ' AS G E N E R A L A I R Q U A L I T Y INDICATOR 131 6.4 C O N C L U S I O N 134 C O N C L U S I O N 135 L I T E R A T U R E C I T E D 137 A P P E N D I C E S 152 A P P E N D I X A : F R A S E R V A L L E Y D A T A 153 A P P E N D I X B : H E R B A R I U M D A T A 162 A P P E N D I X C: D I R E C T M E A S U R E M E N T D A T A 167 A P P E N D I X D : T H E G V R D GRIDDED EMISSION M O D E L 170 vii LIST OF TABLES Tab. 1.1: Typical industrial emission point sources for lead, cadmium, chromium, nickel, zinc, and manganese in the Fraser Valley. 35 Tab. 3.1: Given certified values and analyzed values for 5 reference materials. 54 Tab. 3.2: Intraspecific variation at Stanley Park. 56 Tab. 3.3: Intraspecific variation at Bridal Veil Falls. 56 Tab. 3.4: Repeated digestion and analysis of UEL WS sample. 57 Tab. 3.5: Mean coefficient of variation of duplicate analysis for all samples of the 1993 Fraser Valley Collection. 57 Tab. 3.6: GFAAS precision. 59 Tab. 6.1: Concentration ranges detected in air and moss samples from the GVRD. 126 Tab. 6.2: Atmospheric metal levels at Coquitlam Municipal Hall. 1975 - 1990. 127 Tab. Al: Fraser Valley Collection: Sample site location and metal concentration. 153 Tab. A2: Natural and anthropogenic parameters for the Fraser Valley Collection sites. 158 Tab. A3: Spearman rank correlation coefficients for metal values and related data for the Fraser Valley Collection. 160 Tab. BI: Herbarium Collection: Sample site location, collection date and metal 162 concentration. Tab. B2: Mean metal concentration for the GVRD district samples compared to the East Valley samples for the 1960 - 66 collection. 164 Tab. B3: 1960 - 66 Herbarium Collection samples and matched samples from the Fraser Valley 1993 collection. 165 Tab. B4: 1975 - 80 Herbarium Collection samples and matched samples from the Fraser Valley 1993 collection. 166 Tab. CI: Particulate measurements at the GVRD air quality monitoring stations for 1993 and matched moss samples from the Fraser Valley 1993 collection. 167 Tab. C2: Air quality index data (GVRD) and matched moss samples from the Fraser Valley 1993 collection. 168 viii Tab. C3: S0 2 direct measurements for 1993 (GVRD) and matched moss samples from the Fraser Valley 1993 collection. 168 Tab. C4: NO x direct measurements for 1993 (GVRD) and matched moss samples from the Fraser Valley 1993 collection. 169 Tab. C5: Spearman rank correlation coefficients for metal concentrations of moss samples compared to direct measurements. 169 Tab. DI: Point source emission estimates from the GVRD gridded emission model and matched moss samples from the Fraser Valley 1993 collection. 172 Tab. D2: Area source emission estimates from the GVRD gridded emission model and matched moss samples from the Fraser Valley 1993 collection. 173 Tab. D3: Traffic emission estimates from the GVRD gridded emission model and matched moss samples from the Fraser Valley 1993 collection. 174 Tab. D4: Off-road traffic emission estimates from the GVRD gridded emission model and matched moss samples from the Fraser Valley 1993 collection. 175 Tab. D5: Spearman rank correlation coefficients for emission estimates from the GVRD gridded emission model and metal concentration from matched moss sample's from the Fraser Valley 1993 collection. 176 ix LIST OF FIGURES Fig. 1.1: Methods of bioindication. 4 Fig. 1.2: Heavy metal interactions in the biosphere. 16 Fig. 1.3: The Lower Fraser Valley study area. 29 Fig. 1.4: Annual average wind speed and direction in the Vancouver area. 31 Fig. 1.5: Schematic diagram of wind flows over Vancouver. 32 Fig. 2.1: Sample sites for the Fraser Valley 1993 Collection. 41 Fig. 2.2: Sample sites for the 1960 - 66 Herbarium Collection. 49 Fig. 2.3: Sample sites for the 1975 - 80 Herbarium Collection. 49 Fig. 4.1: Lead concentration in samples of Isothecium stoloniferum. from the Fraser Valley 1993 collection. 62 Fig. 4.2: Cadmium concentration in samples of Isothecium stoloniferum from the Fraser Valley 1993 collection. 64 Fig. 4.3: Chromium concentration in samples of Isothecium stoloniferum from the Fraser Valley 1993 collection. 66 Fig. 4.4: Nickel concentration in samples of Isothecium stoloniferum. from the Fraser Valley 1993 collection. 68 Fig. 4.5: Zinc concentration in samples of Isothecium stoloniferum. from the Fraser Valley 1993 collection. 70 Fig. 4.6: Manganese concentration in samples of Isothecium stoloniferum. from the Fraser Valley 1993 collection. 72 Fig. 4.7: Metal index for samples of Isothecium stoloniferum from the Fraser Valley 1993 collection. 74 Fig. 4.8: Annual precipitation in the Fraser Valley 77 Fig. 4.9: Population density in 0.5 - 5 km rings aroung the Fraser Valley Collection sites. 81 Fig. 4.10: Lead and cadmium emissions in the Fraser Valley 84 Fig. 4.11: Chromium and nickel emissions in the Fraser Valley 84 Fig. 4.12: Zinc and manganese emissions in the Fraser Valley 85 Fig. 4.13: Comparison of results from Fraser Valley 1993 collection from the present study to resent moss method studies from Europe (Pb, Cd, Cr). 90 Fig. 4.13a: Comparison of results from Fraser Valley 1993 collection from the 90a present study to resent moss method studies from Europe (Ni, Zn). x Fig. 5.1: Lead concentration in herbarium specimen of Isothecium stoloniferum collected in 1960 - 66. 97 Fig. 5.2: Cadmium concentration in herbarium specimen of Isothecium stoloniferum collected in 1960 - 66. 97 Fig. 5.3: Chromium concentration in herbarium specimen of Isothecium, stoloniferum collected in 1960 - 66. 98 Fig. 5.4: Nickel concentration in herbarium specimen of Isothecium stoloniferum. collected in 1960 - 66. 98 Fig. 5.5: Zinc concentration in herbarium specimen of Isothecium stoloniferum. collected in 1960 - 66. 99 Fig. 5.6: Manganese concentration in herbarium specimen of Isothecium stoloniferum collected in 1960 - 66. 99 Fig. 5.7: Lead concentration in herbarium specimen of Isothecium stoloniferum collected in 1975 - 80. 101 Fig. 5.8: Cadmium concentration in herbarium specimen of Isothecium stoloniferum collected in 1975 - 80. 101 Fig. 5.9: Chromium concentration in herbarium specimen of Isothecium. stoloniferum collected in 1975 - 80. 102 Fig. 5.10: Nickel concentration in herbarium specimen of Isothecium stoloniferum collected in 1975- 80. 102 Fig. 5.11: Zinc concentration in herbarium specimen of Isothecium. stoloniferum collected in 1975 - 80. 103 Fig. 5.12: Manganese concentration in herbarium specimen of Isothecium. stoloniferum collected in 1975 - 80. 103 Fig. 5.13: Comparison of metal concentrations for the three different collection times (1960 - 66, 1975 - 80, 1993). 104 Fig. 5.14: Comparison of metal concentrations (Pb, Cd, Cr) in samples from the 1960 - 66 collection to metal concentrations from moss samples from matched sites from the Fraser Valley 1993 collection. 106 Fig. 5.14a: Comparison of metal concentrations (Ni, Zn, Mn) in samples from the 1960 - 66 collection to metal concentrations from moss samples from matched sites from the Fraser Valley 1993 collection. 106a Fig. 5.15: Comparison of metal concentrations (Pb, Cd, Cr) in samples from the 1975 - 80 collection to metal concentrations from moss samples from matched sites from the Fraser Valley 1993 collection. 107 Fig. 5.15a: Comparison of metal concentrations (Ni, Zn, Mn) in samples from the 1975.- 80 collection to metal concentrations from moss samples from matched sites from the Fraser Valley 1993 collection. 107 a Fig. 5.16: Site time line analysis for the University Endowment Lands. 109 Fig. 5.17: Site time line analysis for the UBC Research Forest. 110 xi Fig. 5.18: Site time line analysis for Bridal Veil Falls Park. 111 Fig. 5.19: Space heating fuels in British Columbia, 1953 - 1990. 116 Fig. 5.20: Sales of leaded and unleaded gasoline in Canada. 118 Fig. 5.21: Suspended particulate lead in the ambient air of the Greater Vancouver Regional District. 119 Fig. 5.22: Comparison of the herbarium results to literature data (Pb, Cd, Cr). 121 Fig. 5.22a: Comparison of the herbarium results to literature data (Ni, Zn). 121a Fig. 6.1: Direct air measurements of particulate matter in the Fraser Valley. 128 Fig. 6.2: Particulates in the ambient air of the Fraser Valley. 1973 - 1993. 130 Fig. 6.3: Air quality index readings in the Fraser Valley. 131 Fig. 6.4: Direct air measurements of NOx in the Fraser Valley. 133 Fig. 6.4: Direct air measurements of S0 2 in the Fraser Valley. 133 Fig. A l : Fraser Valley Collection: Frequency distribution for lead. 155 Fig. A2: Fraser Valley Collection: Frequency distribution for cadmium. 155 Fig. A3: Fraser Valley Collection: Frequency distribution for chromium. 156 Fig. A4: Fraser Valley Collection: Frequency distribution for nickel. 156 Fig. A5: Fraser Valley Collection: Frequency distribution for zinc. 157 Fig. A6: Fraser Valley Collection: Frequency distribution for manganese. 157 Fig. A7: Precipitation map for the Fraser Valley. 161 Fig. A8: Precipitation map for the Vancouver Area. 161 Fig. Dl : The Lower Fraser Basin. Gridsquares used in the GVRD gridded emission model. 171 Fig. D2: Percentage of pollutants emitted by the area, point and mobile source, and by gasoline marketing (GVRD) 177 Fig. D3: Percentage of pollutants emitted by the various point sources. 178 Fig. D4: Percentage of pollutants emitted by the various area sources. 179 Fig. D5: Percentage of pollutants emitted by the various mobile sources. 180 xii ABBREVIATIONS AQI Air Quality Index B.C. British Columbia B.D.L. Below Detection Limit Cd Cadmium Cr Chromium d.w. dry weight GFAAS Graphite Furnace Atomic Absorption Spectrophotometry GVRD Greater Vancouver Regional District MMT Methylcyclopentadienyl manganese tricarbonyl Mn Manganese Ni Nickel Pb Lead ppb parts per billion ppm parts per million U.B.C. University of British Columbia ug microgram um micrometer Zn Zinc xiii ACKNOWLEDGEMENTS I would like to thank all the people without this thesis would have not been possible. Thanks are extended to the members of the supervisory committee: Dr. David Turpin for the initial idea and enthusiasm, Dr. Will" Schofield for patiently teaching moss identification, and Drs. Gary Bradfield and Les Lavkulich for statistical advise. Alice Kenney and Dr. Hans Schreier are thanked for production of countless GIS maps. I am thankful to the Oceanography Department at UBC for providing the analytical equipment. Special thanks are due to Bert Mueller for his technical advise. The GVRD Air Quality & Source Control Department is thanked for their extensive cooperation: Les Fraser, for providing direct air measurement data, Michel de Spot for information regarding metal emission permits and Mahmood Virani for data from the GVRD 'gridded emission model'. I also would like to thank Dr. Michael DeAbreu (Environment Canada) for data from the 'toxics model', Wayne Belzer and Bruce Thompson (Environment Canada) and Muhammad Rafig (B.C. Ministry of Environment) for additional information and stimulating discussions. Funding for this study was provided by an Eco-Research grant awarded to the Centre of Sustainable Development and the Westwater Research Centre by the Tri-Council secretariat of the Federal Granting Councils for the interdisciplinary 'Lower Fraser Basin Ecosystem Study'. Last but surely not least I would like to thank all my friends and my family for their continuing support. xiv CHAPTER 1: INTRODUCTION 1.1 General Introduction The lower Fraser Valley, in the southwestern corner of British Columbia, is Canada's third largest metropolitan area. Its mild climate, beautiful landscape and favourable economy attract thousands of new residents every year. Population growth and economic development of the area bring about pollution problems typical for large cities worldwide. Heavy metals, as one component of atmospheric pollution, should be carefully controlled and monitored to ensure minimal risk for public health. Industrial processes, traffic and fossil fuel combustion, the dominant heavy metal sources, are prominent throughout the Fraser Valley. Direct air sampling can accurately assess the immediate risk of high atmospheric heavy metal levels. In order to characterize regional differences of atmospheric metals at lower levels, however, a more sensitive measuring device is required. Bioindication can provide an inexpensive and effective supplement to direct air sampling. Mosses, have long proven to be ideal monitoring organisms for atmospheric heavy metals. Their element content is derived directiy from the atmosphere and the tissue is able to accumulate metal ions for a long period of time. The 'moss method' is especially suitable for coastal British Columbia which, enhanced by its wet climate, features an abundant moss flora. Collection and analysis of several moss samples from diverse sites in the lower Fraser Valley can illustrate the regional atmospheric metal distribution, even outside the Greater. Vancouver area, where the district's government (GVRD) operates a direct air sampling network. Relation to population density, traffic volume, fossil fuel combustion and industrial activity can characterize local emission 1 sources. Analysis of herbarium specimens can illustrate historical air quality changes and provide insight on whether or not improved knowledge, industrial change and new emission control technology are able to withstand or even reduce particulate metal emission in this densely populated area. 1.2 Literature Review: Bioindication 1.2.1 General Bioindication Bioindication, as a tool to assess anthropogenic pollution, has been developed since Grindon and Nylander published the first accounts on changes in plant species composition related to air pollution in the mid 19th century (Showman 1988, Arndt & Fomin 1993). During the past 30 years many bioindication methods became widely accepted and implemented in standardized monitoring programs (Arndt & Fomin 1993). Bioindication is now defined as the "time-dependent, sensitive response of measurable quantities of biological objects and systems to anthropogenic influences on the environment" (Stoecker 1980 as cited in Hertz 1991). Bioindication can be differentiated into three basic approaches: indication, testing and monitoring (Arndt 1982, Halbwachs & Arndt 1991). Indication describes non-quantifiable responses to environmental conditions. Testing is used for highly quantifiable responses in a controlled laboratory setting. Monitoring, which is used in this study, describes bioindication in which an organism shows a quantifiable response to non-controlled environmental changes in a field situation (Arndt & Halbwachs 1991). Monitoring is named sensitive when environmental changes cause visible damage, or accumulative, when the monitoring 2 organism accumulates the pollutant, and environmental change is detected by chemical analysis (Steubing 1976 & Stoecker 1980 as cited in Hertz 1991). Monitoring can be either passive, if organisms are taken from their original environment, or active if the organism is imported into the local environment (Steubing 1982, Amdt 1982). Figure 1 shows an overview of the different bioindication methods. The use of the moss method employed in this study represents passive, accumulative biomonitoring. Passive Active Monitoring Testing Sensitive Accumulative Fig. 1.1: Methods of Bioindication 1.2.2 Bioindicator Organisms Many different organisms have been utilized as bioindicators for water, air, and soil pollution. Independent of bioindication type (Fig. 1), pollutant or ecosystem, all bioindicators need to meet the following requirements in order to assess environmental quality in a reliable way (Arndt & Halbwachs 1991). • Accuracy: The response of the organism must be caused by only the environmental changes under examination. For monitoring and testing it is essential that the response level is related directly to the level of environmental change. 3 • Reproducibility: The response to environmental change must be reproducible with different individuals of the same bioindicator organism. • Sensitivity: The organism must be sensitive to environmental change. It is preferable that it detects changes in environmental quality at low levels, allowing for an early warning system. • Localized Cause - Effect Relationship: The observed response must be the result of exposure to environmental change within a defined ecosystem. Motility of an organism has to be considered when used for bioindication. A large number of plants, animals, and fungi conform to those criteria and are used to assess different aspects of environmental quality in a variety of ecosystems. Although plants, due to their immobility, are generally preferred, some animal systems have proven effective for various applications, specifically pertaining to element accumulation. Earthworms, for example, are used to assess soil metal content. Chlorinated hydrocarbons and metals in feathers of certain bird species can relate to the chemical composition of their food sources (Hertz 1991). Caribou meat from Northern Canada was analyzed to measure radioactivity transport from the Chernobyl nuclear reactor accident (Taylor et al. 1988). In the marine environment, molluscs and bivalves are reliable bioindicators of heavy metals (Hertz 1991). High metal concentrations in freshwater bodies can be detected through a rapid decline in the Daphnia population (Mucha & Roesingh 1991). Fungal species are also used as bioindicators for element assessment, usually with respect to soil contamination (Hertz 1991). The Plant kingdom, however, contributes most bioindicators. Absence or presence of certain lichen species 4 can indicate gaseous air pollution (Huckaby 1993, Bartholomess & Wuerzner 1993). Leaf necroses in special tobacco or poplar clones are related to high ozone levels in the ambient air (TUEV 1991, Arndt et al. 1991). The dying forest in Germany, known as 'Waldsterben' is a passive sensitive indicator for the general decline of environmental quality (Heinrich & Hergt 1990). Analysis of grasses, wild rice, conifer needles, leaves, bark or wood from deciduous trees, gives insight into elemental composition of their soil and the ambient air (Pip 1993, Keller & Matyssek 1991, Herrmann & Baumgartner 1987, Herrmann et al. 1978). Dioxins, furans, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, hydrogen fluroides, radioactive elements and heavy metals in air, soil and water can be detected by various plant bioindication systems (Nobel et al. 1991, Mucha & Roesingh 1991, Thomas 1980, Hutchinson-Benson et al. 1985). Some of the methods are still in the developmental stages, such as the use of poplar clones for ozone detection, whereas others such as the use of mosses for detection of heavy metals, are already standard practice of governmental airmonitoring programs in many countries (Ruehling et al. 1987, Herpin 1994). 1.1.3 The "Moss Method" The use of mosses as biomonitors for atmospheric heavy metal pollution must be credited to Ruehling & Tyler (1968), who were the first to relate heavy metal content in moss tissue to air pollution. In the years since then the moss method has been further developed and standardized, and is now widely used in air pollution monitoring (Tyler 1990, Burton 1990, Herrmann 1990, Puckett 1988, Martin & Coughtrey 1982). Surveying 5 the atmospheric metal content of whole countries or large areas thereof has been carried out throughout the world. Most studies have focused on the Scandinavian countries (Ruehling & Tyler 1968, 1969, 1971, 1973, 1984, Ruehling et al. 1987, Rasmussen 1977, Grodzinska et al. 1991), but other European countries, including Germany (Hen-man 1976, Thomas & Herman 1980, Herpin 1994), Poland (Grodzinska 1978, Grodzinska et al. 1990), England (Ellison et al. 1976), Ireland (Loetschert 1982), Scotland (Yule & Llyod 1984) and Iceland (Schunke & Thomas 1983, Thomas & Schunke 1984) have also been surveyed. A more limited number of studies treat areas elsewhere, e.g. the N.E. United States (Groet 1976), NW Ontario, Canada (Rinne & Barclay-Estaip 1980) and New Zealand (Ward et al. 1977). In addition to area surveying, the moss method has been employed also to estimate emissions from point sources such as mines, metal smelters, pulp & paper mills, power plants or other industrial operations (Goodman & Roberts 1971, Burkitt et al. 1972, LeBlanc et al. 1974, Pilegaard 1979, Barclay-Estrup & Rinne 1979, Folkeson 181, Herrman & Huebner 1984, Kansanen & Venetvaara 1991). Herbarium collections of moss species can be analyzed to estimate historic pollution levels and relate observed changes in metal content to changes in anthropogenic activities (Ruehling & Tyler 1968, 1969, 1984 Rasmussen 1977, Grodzinska etal. 1990). 1.2.4 Ion Uptake - Basic Concepts of the 'Moss Method' Bryophytes exhibit several properties essential for reliable monitoring of atmospheric heavy metal pollution. Tyler (1990) summarizes these as follows: 1) Mineral nutrition (i.e. also heavy metal ions) is chiefly derived from wet and dry atmospheric deposition. 6 2) Many species lack a cuticle or epidermal layers which facilitates easy permeability for water and nuttients. 3) Cell wall constituents have numerous negatively charged groups to act as efficient cation exchangers for heavy metal ions. 4) Longevity of shoots allows for accumulation of pollutants over a considerable time span. 5) Simplicity and cheapness of technique compared to direct deposition sampling with technical measuring devices. 6) Many species are very abundant and widespread allowing for large scale surveying. 1.2.4.1 Uptake from Atmospheric Sources Pleurocarpous, epiphytic mosses do not possess real roots and rarely, an internal conducting system, such as hydroids and leptoids common in some acrocarpous moss species. This leads to ectohydric fluid conduction, depending on atmospheric deposition for water and mineral uptake (Puckett 1988). Many species do not possess a cuticle or epidermis inhibiting metal ion uptake. In addition, unistratose leaves exhibit a large surface to volume ratio for increased ion uptake from deposition (Tyler 1990). Tamm 1953 (as cited in Brown 1982) first recognized atmospheric deposition as the main nutrient source for the pleurocarpous woodland moss Hylocomium splendens. It was later confirmed that, even though some acrocarpous mosses show substrate dependence (Puckett 1988, Tyler 1990), pleurocarpous mosses generally derive their nutrients from aerial sources. No relationship between element content of moss tissue and tree bark or soil as substrate was found for pleurocarpous mosses (Huckabee & Janzen 1975, Ward et 7 al. 1977, Johnson & Rasmussen 1976, Rasmussen 1978), but significant correlation between element content in precipitation and exposed moss tissue is reported. (Pilegaard 1979, Thomas 1983, Ruehling et al. 1987). 1.2.4.2 Ion Accumulation and Cation Exchange Mosses are preferred over higher plants as bioindicators, because they accumulate metals efficiently, allowing for background analysis even when metal levels are low. Metal content in moss tissue can be up to 20 times higher than in vascular plants collected at the same sites (Ruehling & Tyler 1968, Tyler 1972, LeBlanc et al. 1974, Thomas 1986). Leaf morphology and ectohydric water conduction aid in particle and water entrapment (Clough 1974, Brown 1984) leading to increased metal uptake. The ability to accumulate metals does not only depend on the water and particulate retention on the surface, but also on the ion exchange capacity of the particular species. Metal ions either dissolved in wet deposition or solubilized from trapped dry deposition by precipitation, are bound to fixed negative charges in the cell wall, following physio-chemical processes (Brown 1982, 1984). Carboxyl groups in unesterfied uronic or pectic acids, specifically poly-galacturonic acids, act as principal cation acceptors (Knight et al. 1961, Clymo 1963, Brown 1984). In addition, proteins are suspected to provide sulfur and nitrogen based cation exchange sites, to accept mainly class B cations, (see section 1.3.1 for discussion of terms) (Brown 1982, Brown & Wells 1988, 1990). Sorption and retention of cations at these fixed negative charges depend on valence state and affinity of the cation to the specific ligand. General preferences for metal sorption is reported as: monovalent class A < divalent class A < divalent borderline < divalent class B (Brown & 8 Wells 1988). Ruehling & Tyler (1970) report a displacement of mainly class A metals, Ca2 +, Mg 2 + , K + and to a smaller amount Na+ and Mn 2 +, by the borderline elements Cu 2 + and Ni 2 + . They also report general sorption preferences in Hylocomium splendens as Pb > Cu > Cd, Ni > Zn, Mn, which closely reflects the general ligand affinity for borderline elements, Pb > Cu > Cd > Ni > Zn > Mn given by Nieboer and Richardson (1980). 1.2.4.3 Element Content in different Moss Parts Element accumulation in relation to different parts of a moss plant has been investigated in several studies. Older, brown portions of a moss cushion exhibit a larger amount of divalent heavy metal ions than green, growing parts, whereas nutrient ions are often more abundant in the younger, green shoots (Pakarinen & Rinne 1979, Brown 82, 84, Brown & Brown 1989). Observed upward movement of nutrient ions, mainly Class A ions, can be explained by a loose binding to the fixed negative charges in the cell wall and nutrient recycling in the growing apices (Brown 1990). Ruehling & Tyler (1970) disregard translocation for divalent, mainly borderline elements, as these show a stable binding to the cation exchange sites. Instead, a longer exposure to atmospheric deposition, loss of biomass via decomposition, or contamination through soil particles are generally thought to be responsible for higher heavy metal contents in decaying moss parts (Pakarinen & Rinne 1979, Brown & Brown 1989). Analysis of the annual increments of Hylocomium splendens showed similar metal content in the green second, third and fourth annual increment, as compared to the not yet fully developed first segment, and the older fifth and sixth segments (Ruehling & Tyler 1970). Brown and Brown (1989) report some translocation of zinc and nickel within green shoots of 9 Rhytidiadelphus squarrosus, but no translocation of lead and copper, which possess class B characteristics and bind more firmly to the cation exchange cites (Nieboer & Richardson 1980). In addition to element content variability due to age of different segments, moss stems seem to accumulate ions less efficiently than leaves. The many layered tissue and the coverage by the leaves, decrease the surface area exposed to deposition (Loetschert et al. 1975 as cited in Brown 1982, Maab 1989 as cited in Bates 1992). With respect to these variations it is essential, in bioindication studies, to analyze tissue of the same age and structure from each of the moss samples. 1.2.4.4 Interspecies Variation Interspecies variation in element content has to be assessed carefully, whenever element levels of different species are compared. Although a few reports indicate the absence of species related differences in lead or zinc accumulation (Ruehling & Tyler 1968, Barclay-Estrup & Rinne 1978), most authors recognize interspecies variation. Folkeson (1979) finds that Pleurozium schreberi and Dicranum polysetum. exhibit up to 70% lower metal levels than Hylocomium splendens, whereas Hypnum cupressiforme and Pohlia nutans show up to 70 % higher levels than Hylocomium splendens. This corresponds to LeBlanc et al. (1974) who report higher accumulation levels in Hylocomium. splendens, than in Pleurozium. schreberi. Isothecium. myosuroides and Isothecium. myurum, were found to accumulate ions at a level similar to Hypnum. cupressiforme, but significantly lower than species of Homalothecium. and Neckera species (Rasmussen 1977). 10 Differences in ion accumulation could reflect differences in "sclerophyllic" content (Lopez & Carballeiro 1993) influencing the biomass/dry weight ratio. Polytrichum. commune, with high "sclerophyllic content", was shown to have lower metal content compared to some feather mosses (Pakarinen & Rinne 1979). As leaf morphology is important for deposition entrapment (Brown 1984), variable leaf forms could also account for interspecies variation. The amount of polyuronic acid (Knight et al. 1961), or more accurately the amount of esterfication thereof, reflecting the availability of cation exchange sites, also relates to the species-dependent accumulation rates (Rouzere et al. 1986 as cited in Bates 1992). 1.2.4.5 Effect of Precipitation, Canopy and Exposure Increased precipitation leads to higher deposition rates of heavy metal ions onto the moss tissue (Lazrus et al. as cited in Groet 1976). Elevated lead levels in Hypnum cupressiforme and Hylocomium splendens from higher altitude sites, could be related to higher precipitation, as compared to lower altitude sites (Ruehling & Tyler 1969). Most studies acknowledge local dependence of element content on precipitation amount, but fail to establish a clear correlation, as anthropogenic influences obliterate the precipitation effect (Ruehling & Tyler 1968, Groet 1976, Thomas & Herrmann 1980). Grodzinska (1978) suggests that precipitation influence can be the main source for variation, in areas with similar pollution regime. Variation in pH of precipitation can, on one hand, leach ions from the moss tissue, but, on the other hand, increase ion availability by enhanced solubilization of metals from dry deposition (Rasmussen 1980). Response of ion accumulation, therefore, might 11 depend on the specific ligand affinity. Raeymaekers (1987) shows slightly increased copper and zinc levels, decreased manganese levels and constant lead levels, in more acidic precipitation. The influence of canopy cover on metal content has not been clearly demonstrated; Rasmussen (1980) reports no difference in metal content between canopy-covered or exposed mosses, Rinne & Barclay-Estrup (1980), however, found significantly higher element content in Pleurozium, schreberi growing under a forest canopy, than in samples from open sites. Exposure of mosses on the tree shows some influence as well. Hypnum cupressiforme had a slightly increased element content derived from accumulation from stem flow, when collected from a vertical tree as opposed to a horizontal log. Researchers avoid variation by canopy and exposition, either by collecting all samples from open sites (Ruehling & Tyler 1973, Groet 1976, Ruehling et al. 1987, Herpin 94), or by collecting only from vertical trees shaded by canopy (Thomas 1983). 12 1.3 Literature Review: Heavy Metals 1.3.1 Terminology • The term 'heavy metal' is traditionally applied to elements with a density greater than 5 g/cm3 independent of the wide variety of physical and chemical properties of the 69 elements that fall into this category (Martin & Coughtrey 1982). This classification is neither applied consistently throughout the literature (Heinrich & Hergt 1990, Nieboer & Richardson 1980) nor does it have any relevance to biological or toxicological applications. Nieboer and Richardson (1980) introduced a now widely accepted, biologically applicable classification, based upon binding affinities of metals towards ligands, and the stability of such metal ion/ligand complexes. They differentiate, between oxygen seeking class A elements and nitrogen or sulphur-seeking class B elements and a borderline class, for metals of intermediate character between class A and class B. Generally, class B elements have a higher affinity to and form more stable complexes with any ligand than class A elements, but they do prefer sulphur or nitrogen ligands. Elements commonly referred to as 'heavy metals' are class B or borderline elements. Cu 2 +, Hg 2 \ Cu\ Pb(IV) are typical class B elements. Mn 2 \ Zn2 +, Cr2 +, Ni 2 + , Cd 2 +, Cu 2 +, Pb2+ are examples "of borderline elements with increasing class B characteristics in the order listed. In the present study, to avoid more 'termini technici', the term 'heavy metal' is used nevertheless, on the assumption that the reader has a general understanding of Nieboer and Richardson's concept. 13 1.3.2 Heavy Metals in the Biosphere Heavy metals occur naturally in a wide variety of geo-chemical materials, such as minerals and fossil fuels (Wedepohl 1991, Pacyna 1986a). Heavy metal pollution refers to an increased occurrence of heavy metals in the environment, resulting from natural or anthropogenic processes. This is contrary to many contamination situations, where a non-natural substance is newly introduced into the environment (Martin & Coughtrey 1982). Natural processes, such as volcanic activity, soilborne windblown dust, forest wild fires, exudations from vegetation and seaspray, can locally contribute significantly to heavy metal pollution, but are minor compared to anthropogenic sources at a global scale (Pacyna 1986b). The principal anthropogenic source is the combustion of fossil fuels for power generation, industrial processes, traffic and space heating. Mining, smeltering, metal processing, manufacturing and waste incineration are other industrial sources (Puxbaum 1991). Once emitted, metals are distributed mainly in the environment by air, water and sediments. Most will accumulate permanently in the soil or in sediments at river or lake bottoms. Uptake into the foodchain, i.e. plants, animals and humans, can occur from either dispersal or accumulation media (Martin & Coughtrey 1982). For an excellent overview see Kabata-Pendias & Pendias (1992). Figure 2 summarizes the interactions of metals in the biosphere. 1.3.3 Heavy Metals in the Atmosphere Heavy metals in the atmosphere are present mainly as particles (Puxbaum 1991). Whitby (1978) differentiates between fine and medium particles (0.0005 - 0.1 urn / 0.1 - 2.5 urn) 14 Fig. 1.2: Heavy metal interactions in the biosphere (modified from Martin &Coughtrey 1980) 15 and coarse particles (2.5 - 100 um). Heavy metals originating from fuel combustion are often in the gaseous state when first emitted (Puxbaum 1991), but condense and subsequently coagulate to form fine and medium particles (Sugimae 1986). These conform to the air stream flow, exhibit a slow deposition rate (Chamberlain 1986), and contribute mostly to elevated heavy metal background levels in the ambient air, without direct relation to any particular source (Saunders & Godzik 1986). Heavy metals in coarse particles, originate from abrasion, erosion and dust or fly-ash producing processes (Sugimae 1986). Coarse particles are deposited close to their emission source as they are subject to sedimentation, due to gravity (Chamberlain 1986, Saunders & Godzik 1986). Heavy metals in particulates can fall as dry or wet deposition. Dry deposition rates depend on particle size and density, wind velocity, height of emission source and characteristics of the deposition surface (Sehmel 1980). Elements from dry deposited particles are easily solubilized on the surface in the presence of water (Salomons 1986). Wet deposition, where very fine particles are incorporated into the formation of precipitation, facilitating long range transport, is recognized as in-cloud, rain-out deposition. Wet deposition, where fine and medium particles are incorporated from the air through which the precipitation is falling is named sub-cloud, wash-out deposition (Hicks & Johnson 1986). Deposition rates of wet deposition depend on precipitation events and deposition surface characteristics (Puxbaum 1991). Generally speaking, the smaller a particle is, the longer it remains in the air and the more likely it is, that it will be deposited as wet deposition. 16 1.3.4 Sources and Health Effects of Heavy Metals Sources of atmospheric metals and related health effects are diverse. In the following the metals selected for this study, lead, cadmium, chromium, nickel, zinc, and manganese, will be investigated in detail. They are among the most commonly studied metals, because their sources are often abundant in anthropogenic environments. For information on other metals please refer to Merian (1991). 1.3.4.1 Lead Sources: Lead is naturally present in the minerals galena (lead sulfide), cerussite (lead carbonate) or anglesite (lead sulfate) and in traces in oil and coal deposits, soil and vegetation (Ewers & Schlipkoeter 1991, Pacyna 1986a). In these forms lead is generally not available for human uptake, although volcanic activity can cause increased lead availability in localized incidents. Other natural sources are usually of little risk (Pacyna 1986 B). Anthropogenic uses have contributed significantly to atmospheric lead levels in populated areas. (Nriagu 1986). Lead levels range from 1-10 ug/m3 air in urban areas to 0.1-1 ug/m3 in rural and 0.001-0.1 ug/m3 in remote areas (Davidson 1986). The principal source of lead emission, until very recently, was the use of tetraethyl - and tetramethyllead as an anti-knock additive in automotive gasoline. Either unburned organolead in the vapor state or fine particles of PbBrCl (Ewers & Schlipkoeter 1991) were emitted from automotive gasoline combustion. Lead emissions from gasoline in the industrialized countries decreased significantly since the reduction of the lead added to gasoline (Gilli 1989, Pfeffer 1994) and the introduction of unleaded gasoline in the 17 1970's (Royal Society of Canada 1985). In Canada, for example, in 1973, 97% of all gasoline used was leaded, in 1985 only 50% and by 1990 it dropped to 4%, until it was outlawed completely by the end of the same year (Lafleur 1994). Production and recycling of lead-acid batteries, mainly for use in automobiles, persist as traffic-related sources (Adriano 1986). Locally mining, processing and smeltering operations, waste incineration, asphalt and cement operations, as well as oil, coal and wood combustion contribute to elevated levels of particulate leadsulfides, leadsulfate or lead oxides (PbO, Pb02, Pb304) (Pacyna 1986a, Royal Society of Canada 1986). Production of lead sheets, cable sheathings, solder, ammunition, bearing alloys, weights, radioactivity-shielding containers as well as manufacturing of lead glass, ceramics, plastics, and paint are other possible sources (Ewers & Schlipkoeter 1991, Royal Society of Canada 1986). Over 50 % of all lead emissions are in the form of submicron particles (Harrison 1973), and are therefore subject to long-range transport (Steinnes 1986, Amundsen et al. 1989). Health implications: Lead from submicron particles easily enters the human body via inhalation (Harrison 1973). Lead has no essential properties and is accumulated primarily in bone tissue (Royal Society of Canada 1986). Both inorganic lead and the more toxic organolead (van Loon 1986), are implicated in a variety of adverse health conditions. Neurobehavioural and neuropsychological problems, such as hyperactivity, reduced concentration, and memory, impaired hand-eye coordination and cognitive dysfunction, resulting in a slightly reduced IQ, have been observed mainly in children, where the blood-brain barrier is not yet fully developed (Ewers & Schlipkoeter 1991, Heinrich & Hergt 1990). Other health problems, related to elevated lead levels in ambient air, are 18 anemia, slightly increased blood pressure, vitamin D deficiency, lowered birth weight and slower motor development in infants (Royal Society of Canada 1986). 1.3.4.2 Cadmium Sources Cadmium containing minerals occur rarely pure, but commonly isomorphic in sulfide ores of zinc, copper and lead (Stoeppler 1991, WHO 1992a). Natural processes, primarily volcanic activity, contribute 10-15% to the total atmospheric cadmium content (Pacyna 1986b, WHO 1992a & b). The rest is accounted for by anthropogenic sources, which gained importance only after world war II, increased significantly until the 1970's, and have been declining continuously since then (Bergbaeck et al. 1994). Principal sources are mining, processing and smeltering of cadmium containing copper and zinc ores, waste incineration, coal and, to a lesser extent, oil and wood combustion, as well as phosphate fertilizer and cement manufacture. (WHO 1992a). Over 90% of the cadmium supply is used for electroplating, Ni-Cd batteries, pigments and plastic stabilizers. Processing, recycling and finally incineration of these products also contribute significantly to elevated atmospheric cadmium levels (Nriagu 1980b). Cigarette smoke is another large emission factor, for the individual or the immediate environment of the individual (Stoeppler 1991). Cadmium sulfides, oxides and hydroxides are the most common forms of cadmium emissions, but other compounds such as cadmium halides, sulfate, nitrate, carbonate and acetate are also likely to be represented in the air, as they are used in a variety of commercial materials (Nriagu 1980a). Emission is usually in the form of particles smaller then 2 urn. It is estimated, that 50% exhibit a long enough 19 residence time in the ambient air to contribute to elevated background levels at a larger scale, in contrast to deposition near the emission source (Nriagu 1980b). Health implications: Cadmium is a highly toxic, non-essential metal. Uptake for non-smoking, occupationally not exposed individuals, is mainly through ingestion, but inhalation close to point sources also contributes significantly (Stoeppler 1991). Inhalation of high cadmium levels is positively correlated to lung cancer. Absorbed cadmium is accumulated in kidneys, causing proteinuria and gluconuria, i.e. dysfunctional renal reabsorption of small proteins, aminoacids and glucose. Kidney dysfunction affects calcium metabolism, in severe cases leading to osteoporosis. Stomach cancer, reversible hemoglobin decrease, liver damage and impaired enzyme activity are among other cadmium induced, adverse health implications (WHO 1992a). 1.3.4.3 Chromium Sources: Chromium, the 21st most common element in the earth's crust, is present in over 40 minerals, but only a few extractable ore deposits of chromite (FeCr204) exist. (Nriagu 1988, Gauglhofer & Bianchi 1991). Based on its abundance in mineral materials, wind blown dust is regarded as the main natural source on a global scale (Pacyna 1986b). Anthropogenic processes include conversion of chromite ores to ferrochrome, which is used for production of steel, stainless steel, and other chromium alloys, and thus the main source of atmospheric chromium emission. (Gauglhofer 1991, Pacyna & Nriagu 1988). Refractory processing, coal and oil combustion, chrome ore refining, waste incineration, 20 cement production, wood impregnation and leather tanning are among other industrial sources (Pacyna & Nriagu 1988). Chromium is also released into the ambient air during production and disposal of chromium containing products, such as audio, video and data storage tapes, stainless steel appliances and gadgets, pigments for paints, photocopy chemicals, rubber, anti-corrosive and anti-freeze chemicals, oil and water resistant finishes, matches, fireworks and fungicides. Chromium ranges in oxidation state from -II to +VI, but is present in the atmosphere mainly in trivalent, hexavalent or metallic forms, depending on the emission source.(Nriagu 1988, Gauglhofer 1991). Emitted particulates of various chromium oxides vary in size from 50 um to 0.1 um. Larger particles originate from windblown dust and emissions from stainless steel production, whereas smaller particles originate from ferrochrome and chromate production, refractory processing and coal combustion (Nriagu & Pacyna 1988). Health implications: General chromium uptake is via inhalation and ingestion. Chromium in its trivalent form is an essential trace element in human nutrition. Deficiency leads to glucose intolerance, elevated insulin and serum cholesterol levels. Recommended daily levels are low (50-200 ug) and no chromium additives are permitted to food or medicinal products (Gauglhofer & Bianchi 1991, WHO 1988, Nieboer & Jusys 1988). Chromium toxicity depends on amount absorbed, valence state and solubility, but human dose response relationships are difficult to establish, as chromium is present in the ambient air in a large variety of compounds and the effects often occur only after prolonged exposure and a long latency period (Yassi & Nieboer 1988). Generally speaking, hexavalent compounds are more toxic than trivalent ones, and insoluble compounds more than 21 soluble ones. Chromium related respiratory cancer is mainly exacerbated by hexavalent compounds, but carcinogenicity of trivalent compounds is also reported (Gauglhofer & Bianchi 1991, Yassi & Nieboer 1988). Skin hypersensitivity, skin and nasal septum ulceration, irritation of the respiratory system, asthma, gastrointestinal damage, kidney and liver dysfunctions are other symptoms observed after prolonged exposure to various chromium compounds (Haines & Nieboer 1988, Nieboer & Yassi 1988). 1.3.4.4 Nickel Sources: Nickel is present in mineral sulfide or oxide ores and often mixed with clay, limestone and shales (Sunderman & Oskarsson 1991, WHO 1991) As it is common in surface material, the main natural emission is from windblown dust (Pacyna 1986b). Anthropogenic emissions are related primarily to combustion of fuel oil for residential space heating and production purposes. Other emission factors, in order of importance, are: nickel production, i.e. mining and smelting, waste incineration, wood combustion, various industrial applications and, to a much lesser extent, coal, gasoline and diesel combustion. (Pacyna 1986b). Nickel is used in over 3000 alloys, e.g. for coins, jewelry, stainless steel, chemical equipment, magnets, engines, etc.. Non-alloy uses of nickel include Ni-Cd batteries, pigments, computer parts, heating elements and electroplating for corrosion protection (Sunderman & Oskarsson 1991). Processing, recycling and disposal via incineration, especially of alloy products, contribute to atmospheric nickel levels. Divalent inorganic nickel, in oxides, sulfates and sulfides, is most common in the atmosphere. Organic nickel carbonyl is emitted, but is rather unstable and quickly forms 22 nickel oxides. Nickel in the air is present in particulates of a wide size range, which correspond directly to the various emission processes. Smaller particles tend to have higher nickel content, which is easily distributed, inhaled and absorbed (WHO 1991). Health implications: Uptake of nickel into the human body is mainly via inhalation, little is added through ingestion. Nickel in trace amount is essential as cofactor in some hydrogenases, dehydrogenases, reductases, and ureases (Hausinger 1992). Toxicity of elevated nickel intake depends on the specific nickel compound. Water soluble nickel salts, such as nickel halides, nitrates or sulfates, are suspected to be co-carcinogenic, promoting tumor formation, in the presence of a cancer initiator such as nitrosoamines or DNP. Water insoluble nickel compounds, such as oxides, hydroxides and sulfides as well as organic nickel carbonyl are suspected individual carcinogens (Sunderman & Oskarsson 1991, Langard 1994, Shi 1994a & b). The respiratory system reacts to nickel exposure not only with lung and nasal cancer, but also with asthma, bronchitis and pneumonitis, when exposed to occupational levels (WHO 1991). Kidney and liver damage, arteriosclerotic lesions, nickel dermatitis and, under extreme exposure, spontaneous abortions and fetal malformation are among other reported responses (WHO 1991, Nieboer & Nriagu 1992, Chashschin et al. 1994). 23 1.3.4.5 Zinc Sources: Zinc is present in almost all minerals. Extractable ore deposits of zinc sulphides, oxides and sulfates are abundant, especially in Canada (Ohnesorge & Wilhelm 1991). Natural emissions of zinc to the atmosphere are mainly from windblown dust, but volcanic activity, exudations from vegetation and forest fires can also add substantial amounts (Pacyna 1986b). Zinc ranks fourth, in minerals, in annual anthropogenic consumption, surpassed only by steel, aluminum and copper (Cammarota 1980). Emissions relate primarily to extraction and processing of zinc from the ore materials. Waste incineration, wood combustion, tire wear, iron and steel galvanizing, and coal combustion are important secondary sources. Production and use of brass and other zinc alloys, pigments, rubber vulcanizing agents, photocopy paper, lubricants, glass, enamel, fabrics, plastics and various chemicals contribute additional zinc to the ambient air (Nriagu & Davidson 1980). Zinc oxide (ZnO) is the most common compound in atmospheric particles, but sulphates, sulfides, chlorides, and organic compounds are also present. Over. 70 % of the atmospheric zinc particles have a diameter of 1-5 um and are, therefore, only partially subject to long-range transport (Ohnesorge & Wilhelm 1991, Nriagu & Davidson 1980). Health implications: Zinc is an essential trace element for human nutrition. It is present in all body parts and fluids; deficiency is often of greater concern than toxicity (Ohnesorge & Wilhelm 1991). It is involved primarily in protein metabolism and function; over 40 zinc metalloenzymes are known, and the role of zinc in DNA and RNA synthesis is well 24 established. Zinc deficiency affects all aspects of growth, development and reproduction. Impaired brain development and function, weakened immune system, eating disorders, vitamin A deficiency, impaired hair, skin and bone development are just a few of many deficiency symptoms (Casey & Hambridge 1980, Wallwork & Sandstead 1993, McClain et al. 1993, Prasad 1993). Zinc toxicity has been observed only under high occupational exposures. Respiratory irritation, metal fume fever with symptoms similar to "flu" are common responses to excessive zinc inhalation. Chronically elevated zinc levels can result in slight copper and calcium deficiencies and affect the immune system (Ohnesorge &Wilhelm 1991). 1.3 .4.6 Manganese Sources: Manganese is a common element, its concentration in the earth's crust amounts to 0.1%. Over 100 minerals contain divalent and tetravalent forms of manganese, but no pure manganese is found in nature. (Schiele 1991). Natural emissions are largely from windblown dust; locally volcanic activity can also be of importance (Pacyna 1986b). Recently anthropogenically introduced manganese has received increased attention, reflecting its use as antiknock additive in gasoline. Organic manganese (MMT) has been added to gasoline as octane improver since 1977 (in Canada) and has now completely replaced lead additives. Automotive tailpipe emissions are presently regarded as the dominant source for atmospheric manganese loadings in Canada (Brault et al. 1994, Loranger et al. 1994, Joselow et al. 1978). In the U.S. MMT has been prohibited because of its questionable health effects. Canada is currently considering a similar ban based on 2 5 pressure from the automotive manufacturers (Westell 1995). Other important anthropogenic emission sources are mining, processing and smeltering of manganese ores, production of ferromanganese for steel and alloy production and fossil fuel combustion (Abbott 1987). Smaller amounts are emitted through waste incineration and fungicide production and application, as well as through production and disposal of various steel products, glass, ceramics, animal foods, rust proofings, electronics and disinfectants (Jaques 1987, Schiele 1991). Manganese is emitted primarily as oxides (Mn02, Mn 30 4) in particulate matter. Particulates from automotive exhaust contain mostly Mn 3 0 4 and are, because of their size of 0.1 - 0.5 um, susceptible to long range transport (Brault etal. 1994, Schiele 1991). Health implications: Manganese is an essential element for human metabolism, but can become toxic if inhaled in high concentrations (Keen & Zidenberg-Cherr 1994). Manganese is involved in carbohydrate, lipid and protein metabolism via several enzymes, as well as in the central nervous system, affecting neurotransmitter chemistiy, release and metabolism and receptor specificity (Wedler 1994). Deficiency is often a larger problem than toxicity and can cause reduced growth, skeletal abnormalities, perturbations in metabolism and impaired reproduction. Some studies also suggest a positive relationship between manganese deficiency and atherosclerosis, arthritis, cancer, diabetes, osteoporosis and other afflictions (Wedler 1994, Keen & Zidenberg-Cherr 1994). Toxic effects have been observed only under occupational conditions and are believed to be of no significance at the low levels caused by MMT combustion (Lynam et al. 1990, 1994, Cooper 1984, Abbott 1987). Occupational health problems include manganism, a central nervous 26 system disorder, with similar symptoms to Parkinson's syndrome, and respiratory irritations, bronchitis, lung inflammation, pneumonitis, and reproductive problems (Abbott 1987, Cooper 1984). 27 1.4 The Fraser Valley - Description of the Study Area 1.4.1 Location The Lower Fraser Valley is located in the southwestern corner of British Columbia in Western Canada. Vancouver, Canada's third largest metropolitan area is located in the western valley; smaller cities such as Langley, Abbotsford and Chilliwack are located in the central part of the valley, and the city of Hope constitutes the eastern most municipality (Fig. 1.3). The Lower Fraser River Basin covers a landbase of 17 000 km2 (Environment Canada 1991). It is bordered in the north by the Coast Mountain range, in the southeast by the Cascade Mountain range. The two mountain chains merge in the east, close to. Hope, forming the Fraser Canyon, where the open river basin ends. The Canada-U.S. border in the south forms a more artificial southern boundary for the study area. Aside from the bordering mountain ranges, most of the area is a wide, open floodplain, characterized by flat and fertile lands, suitable for agriculture and urban development.' 1.4.2 Climate The lower Fraser Valley is characterized by a mild climate. Dominated by onshore flow of Pacific air streams, cool dry summers, and relatively wet mild winters are typical for coastal British Columbia (Hare & Thomas 1974). Temperatures average around 5° in the winter time and about 14° in the summer. Precipitation during the winter months is about four times greater than during the summer (Oke & Hay 1994). Local differences in precipitation are substantial, varying from an annual average of 1000mm in 28 the southern areas, around Richmond and Delta, to 3500mm in the higher reaches of the Coast Mountain range, e.g. at the Cypress or Seymour mountain recreation areas (Fig. A7 & A8). 1.4.3 Wind Patterns and Air Movement Air movement in the Fraser Valley can be separated into the regional winds and the land/sea or mountain/valley breezes that cause air flow when regional winds are light or absent. Frontal storms account for most of the air movement during the winter, whereas local breezes are responsible for much of the air movement during the summer (Oke & Hay 1994). Regional surface winds are predominantly from the east or south east, but are contrasted by a second maximum of northwesterly winds (Fig. 1.4). This general pattern is related to the west-east orientation of the valley, and the northwest southeast orientation of the Georgia Strait, channelling the incoming air from the Pacific into the region. The southern coastal areas are, in general, more exposed to strong air movements than the northern parts. Local areas, such as Port Moody and Coquitlam, at the east end of Burrard Inlet are less exposed, sheltered by the coast mountains, thus they show less air movement and little distinct wind directions (Oke & Hay 1994) In the summer, on calm, clear days sea/land or valley/mountain breezes are a frequently observed phenomenon. The air masses over the land warm faster, rise and draw behind them cooler air from the ocean. Air rising to the upper layers cools off and rejoins the air mass over the ocean. During the day, therefore, breezes blow eastward on 30 Fig. 1.4: Annual average wind speed and direction in the Vancouver area. The length of each arm is proportional to the percentage of winds from each direction (from Oke & Hay 1994) 31 the surface and westward to the Pacific in the upper layers (Fig. 1.5). At night the air over the land cools faster than the air over the ocean, responding to the short heat retaining capacity of land versus water. Air rises over the ocean, directing air movement from the landmasses toward the ocean (Bair 1992, Fairbridge & Oliver 1987). A similar effect tothis sea/land breeze is the mountain/valley breeze. When the sun warms the air masses on the south-exposed slopes of the coast mountains, air rises and flows up-slope. Air masses move from the valley bottom up the mountain slopes. At night the air over the slopes cools, becomes heavier and sinks along the slope down to the valley (Bair 1992). These diurnal breeze patterns account for air movement in the valley, when regional winds are weak or absent (Oke & Hay 1994). Fig. 1.5: Schematic diagram of wind flows over Vancouver. Land/seabreeze (A) by day, and (B) at night. Mountain/valley winds (C) by day, and (D) at night (from Oke & Hay 1994) 32 1.4.4 Population The river basin is the largest habitable region of British Columbia (Environment Canada 1991). More than 50% of all British Columbians live in the lower Fraser basin (Environment Canada 1991). Its mild climate, beautiful landscape and favourable economy attract many new residents, accounting for the rapid population growth, one of the fastest in the country (Moore 1990). Sixty-five percent of the population growth is from migration, 32% from within Canada and 33% from outside Canada. Natural increase from the resident population accounts for the other 35% (GVRD 1993). Most people settle in the western part of the region. The Greater Vancouver Regional district with 1,643,700 residents, houses most of the population. The Central Fraser District with 96,000 inhabitants, the Dewdney-Alouette district with 99,400 inhabitants, and Fraser Cheam district with 76,900 inhabitants, are together home to less than 20% of the total Fraser Valley population (Statistics Canada 1993), but cover a substantially larger landbase, including a large fraction outside the study area. The growing population of the region and the associated rapid urban development infringes not only on agricultural land and wildlife habitat (Moore 1990), but also brings about substantial changes to water and air quality. 1.4.5 Heavy Metals in the Fraser Valley Heavy metals are emitted by a variety of point, area, and mobile sources into the ambient air of the Fraser Valley. Sixty-two percent of the general particulate emissions in the Fraser Valley are emitted by point sources, 16% by area sources and 23% by mobile 33 sources (GVRD 1993). In the following, point sources for heavy metal emissions are discussed with respect to industrial activity. Area sources are discussed on the space heating example and mobile sources are considered in light of the chemical changes in automotive gasoline. 1.4.5.1 Point Sources Point sources are the largest contributor to particulate pollution. In general they include bulk shipping operations and terminals, wood, non-metallic mineral, and paper processing, chemical manufacturing, metal foundries, metal fabrication, petroleum refining, power generation and municipal waste incineration. Bulk shipping and wood processing contribute more then 65% of all particulates, but only a small amount is expected to contain heavy metals. Metal foundries, metal fabrication, petroleum refining, chemical manufacturing and municipal waste incineration, sources emitting metal containing particulates account for only 10% of the total particulate emissions in the Fraser Valley (GVRD 1993b). Most industrial sources emitting heavy metals in the Fraser Valley are located either in the North Burnaby/Port Moody area, or in the industrial areas of South Bumaby, Richmond and Delta. Fewer sources are reported for the area west of this 'industrial belt', and only a couple are located further up the valley, in Maple Ridge, Chilliwack and Harrison Hotsprings. Table 1.1 shows typical emission sources for each metal and indicates the muncipality of their location. 34 T a b . 1.1: Typical industrial emission point sources for lead, cadmium, claromium, nickel, zinc, and manganese in the Fraser Valley. In each municipality listed, at least one emission source has been recorded (GVRD, Environment Canada, personal communication) Production Process Muncipality Lead Metal processing Richmond/Delta/Surrey Industrial incineration Vancouver Municipal refuse incineration Burnaby/Kent Battery production Delta Soldering Burnaby/V ancouver Lubricant production North Vancouver Petroleum product processing Delta Wood processing Maple Ridge/Squamish Cement industry Delta/Richmond Cadmium Metal processing • Surrey Industrial incineration Delta/V ancouver Municipal refuse incineration Burnaby/Kent Petroleum product processing Port Moody/Burnaby/Delta Wood processing Squamish Cement industry Delta/Richmond Chromium Metal processing Surrey Chromium product industry Richmond/Burnaby/V ancouver Petroleum product processing Port Moody, Burnaby, Delta Wood processing New Westminster/Maple Ridge/Squamish Cement industry Delta/Richmond Nickel Industrial incineration Delta Municipal refuse incineration Burnaby/Kent Petroleum product processing Port Moody/Burnaby Wood processing Maple Ridge/Squamish Cement industry Delta Vehicle transmission industry Chilliwack Zinc Metal processing Surrey/Delta/Richmond Electroplating for Zn products Surrey/Richmond/Delta/Burnaby Industrial incineration Delta/Richmond Municipal refuse incineration Burnaby/Kent Petroleum product processing Port Moody/Burnaby Wood processing Squamish Cement industry Delta/Richmond Paving Squamish Vehicle transmission industry Chilliwack Manganese Metal processing Delta/Surrey Municipal refuse incineration Burnaby/Kent Petroleum product processing Burnaby/Port Moody Wood processing Squamish/Maple Ridge Cement industry Delta/Richmond Paving Squamish Vehicle transmission industry Chilliwack 35 1.4.5.2 Area Sources Area sources emitting particulates into the ambient air of the Fraser Valley include space heating, burning, agriculture, landfills and natural sources. The largest contributors, landfills with 27% and agriculture with 21%, are not expected to emit many heavy metals. Space heating, a prominent source for heavy metal emissions, is responsible for a total of 25% of the total particulate emission (GVRD 1993b). Combustion of coal, wood, and oil for space heating contributes significant levels of atmospheric metals. Coal combustion is primarily responsible for lead and zinc emission, whereas wood combustion emits mostly cadmium, but also zinc, lead, and nickel. Oil combustion accounts mainly for atmospheric nickel (Pacyna 1986a). In 1979 nickel emission worldwide was predominantly from oil combustion (Pacyna 1986b). Fossil fuel combustion for space heating in the Fraser Valley has undergone a significant change in the last 30 years. In the mid-century, most homes were heated by wood, coal or other sources; such as sawdust. These fuels were gradually replaced by oil, the principal heating source in the sixties and early seventies. In the late seventies and eighties oil furnaces were replaced by natural gas and electricity fueled systems for efficient and clean space heating (B.C. Ministry of Energy, Mines and Resources 1994). 1.4.5.3 Mobile Sources Mobile sources include cars, trucks, off-road vehicles, trains, ships and aircrafts. Over 75% of the general particulates are emitted from car and truck traffic (GVRD 1993b). Metal emission from automotive vehicles, constitute a major portion of the total 36 atmospheric metals emitted in the Fraser Valley (see Section 1.3.4.). After abandonment of leaded gasoline in Canada, only minor amounts of lead originate from leaded gasoline bought in the United States, where it is still available for use in older automotive models. Other metal emissions from mobile sources include manganese from the new MMT gasoline additive and zinc from tire abrasion (Cass & McRae 1986). In addition, cadmium, chromium, nickel, zinc, and lead are emitted through the use of several lubricants (Pacyna 1986a). The automobile is the transportation of choice for most people in the Lower Fraser Basin. Not many alternatives are available in large parts of the study area. One exception to this is the skytrain connection, from downtown Vancouver to Surrey, providing fast, effective and environmentally friendly public transport. The rest of the area has to rely on the public bus system. Even though well developed, and in part supported by an electric trolley system, it is not an attractive alternative to many people. Transportation by bus is often inconvenient and slower than automotive transportation. There are no public transportation options available for the large population of long-distance commuters, from areas outside the GVRD. The rapid population growth is responsible for an increase in individual vehicle traffic which inadvertently affects the general air quality of the valley. 37 1.5 Objectives In this study the 'moss method' will be used to investigate the atmospheric heavy metal situation of the Fraser Valley. The current distribution of atmospheric metals will be mapped for 1993 and historical changes of the heavy metal levels since the 1960's will be characterized. The concentration of lead, cadmium, chromium, nickel, zinc and manganese will be determined in moss samples from a 1993 collection and from the UBC herbarium. Results will be correlated to natural and anthropogenic factors, to provide an explanation for the observed metal pattern. A comparison to similar studies earned out in Europe will demonstrate the relative pollution level of the Fraser Valley. In addition, the value of the 'moss method' in relation to direct air measurements will be investigated and its potential to be used as a general air quality indicator will be examined. 38 CHAPTER 2 : MATERIALS AND METHODS 2.1 Moss Species The moss species used throughout this study is Isothecium stoloniferum Brid. It is a pleurocarpous1 moss belonging to the family Brachytheciaceae (Ireland et al. 1987). It is common in the study area as an epiphyte of trees and shrubs, as well as on logs, rocks and cliffs (Schofield 1976, 1992). Some authors consider it as a Western North American endemic (Lawton 1971, Schofield 1981), whereas others consider it to be conspecific with the Eastern North American and European species Isothecium myosuroides Brid. (Allen 1983). It has also been treated under the names Isothecium, spiculiferum (Schofield 1992), Hypnum spiculiferum, Eurhynchium stoloniferum, Pseudoisothecium stoloniferum and others (Lawton 1971). Isothecium stoloniferum Brid. was chosen for the survey study because its wide distribution in the study area permits the use of a single species, thus avoiding the need for interspecies calibration (Folkeson 1979). The pleurocarpous growth form and epiphytic habitat ensures an ion uptake derived mainly from atmospheric sources. The most commonly used mosses in similar studies throughout the world, such as Hypnum cupressiforme, Hylocomium splendens and Pleurozium schreberi (Tyler 1990), are present in the "study area but are often not abundant enough for systematic sampling. 1 pleurocarpous refers to a branched growth form with non-terminal sporophytes . These mosses are also often called 'feather mosses'. 39 2.2 Fraser Valley 1993 Collection 2.2.1 Sample Collection Samples of Isothecium stoloniferum. were taken from 62 sites within the study area (Fig. 2.1). Al l samples were taken in the period of 19-8-93 to 24-9-93 in order to eliminate seasonal fluctuations of metal uptake (Markert & Weckert 1989). To obtain an even sample site distribution and appropriate coverage for the area, sample sites were chosen by laying a 10x10 km grid over a map of the study area and locating one site within each grid square with Isothecium stoloniferum present. Each sample site was at least 100m from any minor road or individual house, 200m from any logging road or settlement and at least 500m from any major highway or industrial source, to avoid influence of local emission sources (Ruehling & Tyler 1968, Thomas 1983, Thomas & Schunke 1984). Al l samples were taken from forested areas or in smaller stands of trees. At each sample site 6 individual samples, from different populations of Isothecium stoloniferum, were collected within a 100x100m area. Samples were picked from trees or logs with clean kimwipes, wrapped in kimwipes to avoid metal contamination, and stored separately in brown paper bags to allow air drying. 2.2.2 Sample Processing In the period from 25-9-93 to 31-11-93 dirt-free green shoots representing approx. 2 years growth (Pakarinen & Rinne 1979, Tyler 1990) were separated from the samples with Teflon coated forceps and stainless steel scissors. Forceps and scissors were cleaned thoroughly with distilled deionized water between handling of each individual sample. The separated shoots were wrapped in new kimwipes and stored in paper bags at room temperature until all samples were cleaned. No further cleaning procedures followed so as to retain all deposition associated with the moss tissue (Bates 1992, Herpin 40 41 1994). O.lg of each of the six individual samples from each sample site were combined to form a composite sample. The composite sample was roughly homogenized by cutting the shoots with acid cleaned stainless steel scissors into pieces no larger than 2-3 mm. The composite sample was stored in 30 ml acid cleaned clear plastic vials, with tight closure caps, until digestion. 2.2.3 Digestion and Analysis Two replicates of each composite sample were digested independently, after drying for 14 h at 44°C. O.lg of each composite sample and 5ml cone. H N O 3 (environmental grade - Anachemia), were loaded into 100ml Teflon PFA lined Ultem polyetherimide digestion vessel and digested in a digestion microwave (CEM) for 15 min at 70 PSI. Typically, 10 moss samples, 1 acid blank (5ml H N 0 3 ) and 1 reference sample (see Section 2.4.1), were digested in each microwave cycle. After cooling to room temperature 2ml of the digestate were transferred to 18ml nanopure water (Milli-Q/Millipore) in 30ml high density polyethylene bottles. Material from sample sites 2, 4, 4b, 9, and 57 was limited, therefore only 0.05 gr of dried moss were digested in 2.5ml H N O 3 and 1ml digestate was transferred into 9 ml H 2 O . These 10% H N O 3 digestates were then analyzed by graphite furnace atomic absorption spectrography (GFAAS)(Varian spectrAA-300/Zeeman) with Zeeman background correction and automated sample injection. The graphite furnace was operated with pyrolytic coated platform tubes for lead, cadmium, zinc and manganese analysis and with pyrolytic coated partition tubes for chromium and nickel analysis. Cadmium, nickel and chromium were analyzed in the 10% digestates without further dilution. Lead was analyzed in 5% H N O 3 a f t e r diluting the 10% digestate with nanopure H 2 O by a factor of 2. The digestate was diluted with nanopure H 2 O by a factor of 10 for manganese analysis and zinc analysis was carried out in approx. 2% H N O 3 , after diluting 42 the 10% digestate by a factor of 18 with 2% H N 0 3 . Dilution factors were chosen to meet the optimal measuring concentration for the graphite furnace atomic absorption spectrophotometer. 2.2.4 Data Processing The value obtained for each digestate was corrected for the acid blank reading and the ppm/dry weight moss tissue was calculated. The values for the two replicates from each sample site were averaged for further data analysis and presentation. 2.2.5 Geographical Representation and Statistical Analysis Six maps of the study area were produced, showing the average concentration of each metal at the 62 sample sites. Bars representing the metal concentrations were inserted on a Fraser Valley base map. The results were illustrated in two ways: First, the height of each bar and the label, respond directly to the averaged concentration for this sample site. Second, to simplify the visual assessment of the metal pollution pattern 4 concentration based categories were established for each metal. Categories were based on the polymodal frequency distribution. Frequency distribution diagrams and category limits are given in Appendix A (Fig. A l - A6). These and all other maps were produced by Alice Kenney, Resource Management Science, UBC using a PC Windows based Geographic Information System (MAP INFO). In order to determine the differences between the GVRD and the eastern regions of the study area, sample means from both areas were compared by a Mann-Whitney-U test. The null hypothesis of 'no differences between means' was rejected at p<0.05. 43 2.2.6 The Metal Index In order to establish a general pattern of atmospheric metal pollution in the Fraser Valley, relationships between the distribution patterns of the individual metals was tested with a Spearman rank correlation test. The null hypothesis of "no correlation" was rejected if p<0.05. Based on the significant correlation of lead, cadmium, nickel, and zinc (Tab. A3), a metal index, combining the distribution patterns for the 4 metals, was developed. For each metal, the samples with the 16 highest concentrations were assigned an arbitrary value of 4. The 16 samples with the next lower concentrations were assigned a value of 3. The next 15 samples below were assigned the value 2 and the 15 samples with the lowest concentration received the value 1. Each sample site was assigned 4 values, one for each metal. The 4 values were added, so that now each sample site is characterized by a metal index value between 4 and 16. Therefore, at maximum pollution level, a sample site can receive an index of 16 if the concentration for lead, cadmium, nickel, and zinc was among the highest 16 of the total study area. At minimum pollution levels, a sample site can have a metal index of 4, if concentrations for all metals were among the lowest 15 for the study area. For graphical display the metal index was mapped on the Fraser Valley base map. The metal index was categorized into high indices (14-16), medium indices (11-13), low (8-10) and very low indices (4-7). 2.2.7 Relation to Natural Factors • Precipitation To estimate the influence of precipitation upon the metal concentrations in Isothecium stoloniferum, precipitation data from two different sources were correlated to metal concentrations in the Fraser Valley. First, precipitation data based on climate normals (30 year average) from Stager & Wallis (1968) were used. Precipitation 44 isolines separated 6 zones describing precipitation amounts from <40 inch to >90 inch (= 1016 to 2286 mm) in 10 inch increments for the complete study area. These zones were assigned an arbitrary number from 1 for precipitation < 40 inch to 6 for precipitation > 90 inch. These precipitation numbers were assigned to the moss sampling sites, according to their geographic location. Precipitation values were correlated to the individual metal concentration in the moss samples with a Spearman rank correlation test. The null-hypothesis of "no correlation" was rejected if p<0.05. The original precipitation map, a complete list of assigned precipitation numbers, and statistical results are given in Appendix A (Tab.A2, Fig.A7). Second, selected moss metal concentrations from the GVRD area were compared to a higher resolution precipitation map. Oke & Hay (1994) provide a precipitation isoline map, with 100 mm increments (Fig.A8). Metal concentrations of the 16 samples from the area covered by the Vancouver precipitation map, were correlated to the respective precipitation amount by a Spearman rank con-elation test. The null hypothesis of "no correlation" was rejected if p<0.05. In addition to the statistically interpreted isoline data, the total amount of precipitation for 1993 at 44 sites in the Fraser Valley was obtained from Environment Canada to present a recent precipitation pattern for the whole study area. No statistical correlations were carried out on this data set, as it is available only as point data. However, for visualization of the precipitation pattern in the whole study area the 1993 precipitation data were mapped on the standard Fraser Valley base map (Section 4.3.1). 45 • Elevation To assess the influence of elevation on metal concentrations, elevation of the sample sites was read from 1:50,000 topographical maps (Appendix A, Tab.A2). A Spearman rank correlation test was used to test significant relationships between altitude and metal concentration at the sample sites. The null hypothesis of "no correlation" was rejected if p<0.05. 2.2.8 Relation to Anthropogenic Factors • Population Population density was determined in 0.5 km to 5 km rings around each sample site. The data is based on Census 1991 data from Statistics Canada. A software program (PCensus) was used to extract the number of people residing in the specified areas. The number of people determined for each sample site was mapped on the Fraser Valley base map. Al l population data was provided by Neil Guppy, Department of Anthropology and Sociology, UBC. A Spearman rank correlation test was used to determine the relationship between metal concentrations and population density for the 62 sample sites. The population data are given in Appendix A (Tab.A2). • Industrial activity Industrial operations with known metal emissions to the ambient air were mapped on the Fraser Valley base map. The data were obtained from two sources: First, from the GVRD emission permits (GVRD 1994c) and second from the Environment Canada 'toxics model' (Environment Canada 1995).The GVRD emission permits are issued by the Air Quality & Source Control Department to industrial processes, that emit more than 46 5kg/year of specific metals into the atmosphere. The Environment Canada 'toxics model' estimates metal emissions for specific operations in the Fraser Valley. The model is based on the GVRD gridded emission model (Appendix D) and estimates heavy metal emission from certain industrial processes. In addition, industrial activity is also estimated directly from the GVRD gridded emission model. The model estimates particulate and gaseous emissions from point, area, and mobile sources for 5x5 km gridsquares covering the study area. Point source emissions for each gridsquare were correlated with the metal data for sample sites within the same gridsquare. A Spearman rank correlation test was used and the null hypothesis of 'no correlation' was rejected at p<0.05. More detail about the GVRD gridded emission model and statistical analysis is provided in Appendix D. • Traffic The GVRD gridded emission model estimates particulate and gaseous emissions from mobile sources in 5x5 km gridsquares for the Fraser Valley. Al l emissions are used as an indicator for traffic volume and were tested with a Spearman rank correlation for significant relation ships to the moss metal data. The null hypothesis of 'no correlation' was rejected at p<0.05. Details regarding the model and the statistical analysis are given in Appendix D. 47 2.3 Herbarium Collection 2.3.1 Sample collection Fifty-seven dried Isothecium stoloniferum specimens were obtained from the UBC herbarium, where they were kept in paper packets, stored in shoe boxes. The available material was organized in two approaches in order to maximize information output. First, an area based approach was used, with samples from a fixed time period collected at several locations in the study area. Two collections, one from 1960-66 with 25 samples from the whole study area and another from 1975-1980 with 15 samples mainly from the eastern parts of the area, were obtained. Sample sites vary between the two collections. Second, a local approach was employed, whereby 3 individual sites yielded enough samples to establish an independent timeline: 8 samples from the University Endowment Lands collected between 1949 and 1987, 7 samples from the UBC research forest in Haney collected between 1959 and 1978 and 15 samples from Bridal Veil Falls, near Hope, collected between 1949 and 1986 were identified. Figure 2.2 and 2.3 show the locations of the herbarium collection sample sites. 2.3.2 Sample Processing, Digestion and Analysis From each herbarium sample approx. O.lg of green shoot material was separated, as described in Section 2.2.2 and stored in a packet folded from weighing paper (Fisher Scientific). Herbarium samples were in general digested as outlined in Section 2.2.3, but restricted by the limited availability of the material neither composite samples were produced nor replicates analyzed for any sample. For sample H29, H45 and H48 only 0.05g, for H10 only 0.035g and for HI 8 only 0.045g of moss tissue were available. These 48 Fig. 2.2: Sample sites for the 1960 - 66 Herbarium collection (* indicates sites where an independent timeline was investigated). Fig. 2.3: Sample sites for the 1975 - 80 Herbarium collection (* indicates sites where an independent timeline was investigated). 49 were digested in 2.5 ml HNC^and then 1ml digestate was transferred into 9ml nanopure H 2 0 . GFAAS analysis was carried out as described in Section 2.2.3, with the exception of chromium determination, where the analytical solution was changed to 5% H N O 3 , diluting the original 10% digestate with nanopure H 2 O by a factor of 2, to better fulfill technical requirements of the GFAAS analysis. 2.3.3 Data Processing The values obtained for the digestate were corrected for the acid blank readings and the ppm/dry weight moss tissue was calculated. This value was used in all further analysis. 2.3.4 Geographical Representation and Statistical Analysis Metal concentration in moss samples from the 1960-66 and the 1975-1980 collection were mapped on the Fraser Valley base map. In order to determine the differences between the GVRD and the eastern regions of the study area, sample means from both areas from the 1960-66 collection were compared by a Mann-Whitney-U test. The null hypothesis of 'no differences between means' was rejected at p<0.05. No comparison between the GVRD and the eastern valley was possible for the 1975-80 collections, as all but one sample site were located in the eastern valley. For comparison of the three collections at different time periods (1960-66, 1975-80, 1993) the collection mean was calculated and presented in a bar graph. To provide a statistical comparison, samples from the 1960-66 collection were matched with the geographically nearest sample from the 1993 collection. The mean for the matched values from 1993 was calculated and compared to the mean for the 1960-66 collection with a Mann-Whitney-U test. The null hypothesis of 'no difference between 1960-66 and 1993' was rejected if 50 p<0.05. The same procedure was used for a comparison between the 1975-80 and the 1993 collection. A list of 'matched' sample sites is provided in Appendix B (Tab. B2, B3). 2.4 Qual i ty Contro l and E r r o r Assessment 2.4.1 Accuracy In order to estimate the accuracy of the GFAAS element analysis, 5 different reference materials were repeatedly digested and analyzed as samples. In each microwave cycle, at least one reference sample was digested, with the same methods as those applied to the samples. CRM 281 rye grass (Commission of the European Communities, Community Bureau of Reference) was used as a certified reference material. In addition, Scandinavian moss samples (provided by Dipl.Biol. Uwe Herpin, University of Osnabrueck, Germany), which have been analyzed by a variety of methods in different laboratories, were also analyzed. These were three samples of the moss Pleurozium schreberi (Hedw.) Mitt, from Denmark (Dkl, Dk2) and Sweden (S) and one sample of Hylocomium splendens (Hedw.) B.S.G. from Norway (N). Given values for the reference material were compared to analyzed values with an independent t-test. The null hypothesis of 'no difference was rejected if p<0.05. 2.4.2 Variation among Subsamples In order to assess the intraspecific variation inherent in the composite samples, the 6 subsamples contributing to each composite sample as well as the composite sample itself, were analyzed for 2 sites. Stanley Park represents a typical site with high metal loadings and Bridal Veil Falls represents a typical site with lower metal loadings. Digestion and analysis were carried out as described in Section 2.2.3. This shows the 51 cumulative variation related to variable element content in different moss plants or populations and variation related to the sampling, digestion or analytical methods. Element contents for the 6 sub-samples were reported along with variation reported as coefficient of variation. In addition, the arithmetic mean of the sub-samples and the value obtained for the composite sample were compared. 2.4.3 Precision Precision of digestion and GFAAS analytical techniques was estimated through repeated digestion and analysis of one sample, treating each repeat as an independent sample. The sample used, UEL-WS, was a large composite sample (approx. 8 subsamples) of Isothecium stoloniferum taken from a 200x200 m 2 area in the Pacific Spirit Park, collected separately from the Fraser Valley 1993 collection. The sample was homogenized with mortar and pestle, in liquid nitrogen. Thirteen replicates were digested and analyzed as outlined in Section 2.2.3. In addition each composite sample of the Fraser Valley 1993 collection was routinely digested and analyzed in independent duplicates. The mean coefficient of variation was calculated for both, the repeated samples and the Fraser Valley duplicates. To assess precision of the GFAAS analysis alone, one digestate of the Fraser Valley 1993 samples with high metal readings, (Stanley Park, 3a) and one with low readings (Bridal Veil Falls, 53) were repeatedly analyzed for each element during the complete course of Fraser Valley 1993 sample analysis. 52 2.5 Comparison of the Moss Method to Direct Air Measurements In order to compare the 'moss method' with direct air measurements for the study areas, data were obtained from the GVRD Air Quality & Source Control Department. Comparisons to direct air measurements for heavy metals, particulates, S0 2, NO x and a general air quality index were carried out. Statistically significant relationships were determined with a Spearman rank correlation test for the latter four. Particulate, S0 2, NO x , measurements and the general index were matched to the moss metal data from the sample site closest to the direct air monitoring station. The null hypothesis of 'no correlation between direct measurements and moss data' was rejected at p<0.05. A listing of the direct air measurements and the 'matched' moss data is given in Appendix C (Tab. C1-C4). 53 CHAPTER 3: RESULTS AND DISCUSSION: QUALITY CONTROL AND ERROR ASSESSMENT 3.1 Accuracy Table 3.1 compares the certified or given values for 5 reference materials and the values obtained from analyzing the same reference materials during the present study. In general a good relation was found. Analyzed values for the certified reference material (rye CRM 281) were found to be significantly lower than the given certified value (T-test, p<0.05) for cadmium, chromium and nickel. However, the values for the moss material (Sweden, Norway, Dkl , Dk2) did not show any significant difference for those metals. The only comparison with a moss reference analyzed as having lower values than given, was for Dkl in lead analysis. Al l other reference materials for lead showed good correspondence between given and analyzed values. Tab. 3.1: Given certified values and analyzed values for 5 reference materials (in ppm/ diy weight). Variation is given as standard deviation. * denotes significant differences (p<0.05/t-test), between given and analyzed values. Rye (CRM 281) Sweden Norway Dkl Dk2 Pb certified 2.4 + 0.2 15.6 + 1.3 12.5+1.6 25.3+2.4 18.7 + 2.1 Pb analyzed 2.2 ±0.3 15.8 ±2 .1 11.6 + 0.7 20.9+4.1 * 16.8 ±0.5 Cd certified 0.12 + 0.01 0.37 + 0.09 0.22 + 0.30 0.29 + 0.06 0.26 + 0.07 Cd analyzed 0.10 ±0.01 * 0.37 ±0.06 0.09 ±0.01 0.26 + 0.03 0.24 + 0.01 Ni certified 3.1 +0.6 1.6 + 0.6 2.9 + 0.9 1.6 + 0.4 1.9 + 0.4 Ni analyzed 2.6 ±0.3 * 1.5 ±0.3 2.6 + 0.3 1.9 + 0.1 1.8 + 0.1 Zn certified 31.4 + 2.8 53.4 + 5.8 35.1+4.9 30.0 + 4.3 43.0 + 5.1 Zn analyzed 31.7 ±3 .0 52.7 ±1 .9 35.8 + 1.8 33.8 ±5.6 44.5 ± 9 . 0 Cr certified 2.1 ±0 .4 1.1 ±0 .4 2.3 + 0.7 1.4 + 0.5 1.5 + 0.6 Cr analyzed 1.8 ±0.3 * 1.0 ±0 .3 2.0 ±0.3 1.3 ±0 .4 1.4 ±0 .3 Mn certified 82 + 4 508 + 87 265 + 35 109 + 8 660+ 121 Mn analyzed 85 ± 7 556 + 75 279 + 17 259 + 244 687 ± 1 9 54 3.2 Variation among Subsamples Analysis of the 6 individual subsamples contributing to the composite sample, for two representative sample sites (3a, 53), showed good resemblance between the value obtained for the composite sample and the arithmetic mean of the 6 subsamples (Tab. 3.2, 3.3). Variation among the individual subsamples was large for both locations. Variation for all metals except manganese was higher at the less polluted site at Bridal Veil Falls (53), than the variation at the more polluted site in Stanley Park (3a). The extremely high variation for chromium and nickel at Bridal Veil Falls was related to the outlier values of subsample 5, which may indicate contamination of this particular sample, especially as variation for chromium and nickel at the Stanley Park site was within the normal range. Omitting those outliers, the variation for all metals, except for manganese, ranges between 10 and 25%. This is similar to the variation reported in Thomas (1983), ranging between 14 and 31%. Manganese, both at Bridal Veil Falls and in Stanley Park shows variation around 50%, which might be related to its active role in ion exchange (see Section 1.2.4.2). Thomas and Schunke (1983) also reported higher variation for manganese than for any other analyzed metal. The reported subsample variation is a combination of differences inherent in the moss material and the processing, digesting and analyzing of the tissue, which is assessed in Section 3.3. Variation among subsamples may result from different exposures to wet or dry deposition. Contamination through animal movement or soilborne dust generation, as well as differences in the ion exchange capacity between different moss populations might also influence the element content of the individual subsamples (Bates 1992, Rinne & Barclay Estrup 1980, Ruehling & Tyler 1969, 1971). Note that the subsample variation is reported only for the Fraser Valley 1993 collection, not for the herbarium collection. Moss samples from the herbarium might exhibit more variation, as they were not collected with a pollution survey study in mind. 55 Contamination by the collector, during preparation or storage is not unlikely. The limited material prevented assessment of the variation, but should be kept in mind when one is drawing conclusions on the basis of herbarium material. Tab. 3.2: Intraspecific variation at Stanley Park (sample site 3a). s = standard deviation, cv = coefficient of variation in %, (values except cv are given in ppm/dry weight). Pb Cd Ni Zn Cr Mn composite sample 20.0 0.44 2.9 44.3 0.9 185 subsample 1 24.8 0.44 3.2 48.3 0.9 312 subsample2 22.6 0.47 3.5 49.0 1.0 285 subsample 3 23.8 0.46 3.7 42.2 1.0 157 subsample 4 17.7 0.41 2.2 40.7 0.8 83 subsample 5 15.1 0.38 2.9 41.8 1.1 126 subsample 6 19.8 0.37 2.4 37.1 0.8 141 subsample x (mean) 20.6 0.42 3.0 43.2 0.9 184 subsample s (stds) 3.8 0.04 0.6 4.6 0.1 93 variation (cv) 18.4 9.9 20.1 10.7 12.0 50.3 Tab. 3.3: Intraspecific variation at Bridal Veil Falls (sample site 53). s = standard deviation, cv coefficient of variation in %, (values except cv are given in ppm/dry weight). Pb Cd Ni Zn Cr Mn composite sample 3.0 0.22 1.0 21.3 0.8 34 subsample 1 3.6 0.18 0.9 18.7 0.7 26 subsample 2 2.7 0.20 0.7 18.3 0.6 29 subsample 3 2.2 0.22 0.6 21.3 0.5 26 subsample 4 1.9 0.19 0.7 17.7 0.4 25 subsample 5 2.1 0.16 3.0 23.4 5.2 68 subsample 6 2.3 0.12 0.9 16.2 0.5 37 subsample x (mean) 2.5 0.17 1.1 19.3 1.3 35 subsample s (stds) 0.6 0.03 0.9 2.6 2.0 17 variation (cv) 25.6 17.9 81.6 13.6 145.5 47.9 56 3.3 Precision Precision of digestion and graphite furnace atomic absorption techniques are displayed in Table 3.4, showing results of repeated digestion and analysis of a single sample, UEL-WS, and in Table 3.5, showing the mean coefficient of variation of all samples for the Fraser 1993 collection. Tab. 3.4: Repeated digestion and analysis of UEL WS sample (in ppm/dry weight) repeat # Pb Cd Ni Zn Cr Mn 1 24.5 0.14 2.7 38.9 0.9 545 2 24.4 0.15 2.7 38.5 1.3 563 3 22.0 0.16 2.7 37.1 0.8 491 4 22.3 0.17 3.2 40.5 1.4 523 5 21.9 0.15 2.7 39.2 1.1 482 6 27.4 0.17 2.6 39.2 0.9 463 7 24.1 0.15 2.7 37.8 0.8 456 8 22.9 0.15 2.4 40.6 1.0 479 9 22.4 0.16 2.4 35.3 0.8 475 10 24.2 0.20 2.7 34.8 1.2 495 11 23.6 0.17 2.4 36.8 1.1 445 12 27.0 0.16 2.7 38.3 1.6 497 13 23.9 0.15 2.3 37.5 1.3 503 X 23.9 0.16 2.6 38.0 1.1 494 s 1.7 0.02 0.2 1.8 0.2 34 variation % 7.3 9.9 8.02 4.6 22.6 6.9 Tab. 3.5: Mean coefficient of variation of duplicate analysis for all samples of the 1993 Fraser Valley Collection (in %). Pb Cd Ni Zn Cr Mn mean variation (cv) 8.6 8.3 10.7 6.3 18.4 6.5 57 The variation found in the 13 repeats of the UEL-WS sample was similar to the mean variation of all duplicate Fraser Valley 1993 samples. The mean coefficient of variation for the duplicate analysis of the Fraser Valley 1993 samples was slightly lower than those reported in Herpin (1994), which ranged from 8.0% (Cd) to 25.6% (Ni). Precision for the GFAAS technique alone (Tab. 3.6) was, in general, better than for digestion and GFAAS together (Tab. 3.4), indicating that both techniques accounted for the variation reported in Table 3.4 and Table 3.5. Exception to this was the high variation for nickel and lead, where the digestates with low element content showed higher variation. The digestate with low cadmium content showed also higher variation than the digestate with higher cadmium content. This might be related to a fairly high detection limit compared to the average element content (Tab. 3.6). Chromium showed good precision regarding the GFAAS techniques, but a fairly poor one when digestion and GFAAS were tested in combination. This would suggest that most variation is accounted for by the digestion procedures. A possible cause could be that by taking replicates from the composite sample, the amount of earthborne dust, containing mineral derived chromium (Gauglhofer 1991) might vary between the different digestates. Herpin (1994) also reported a high variation of 19.6% for chromium analysis. Factors influencing precision during the digestion can include: heterogeneity of the composite samples, uncertainties in sample weighing or acid pipetting, and contamination of digestion vessels. Precision during the GFAAS analytical procedures is related to various factors including imprecise sample injection, sample loss during drying or ashing steps, use of a deteriorated standard curve or concentration of sample through H 2 O evaporation during analysis. 58 Tab. 3.6: GFAAS precision. Variation coefficient in % of repeated analysis of the same digestate. Detection limit in ppm/dry weight moss, calculated after Rubinson 1987. Variation # of times average Standard Detection coefficient (%) analyzed (n) (ppm/d.w.) deviation limit Pblow 8.4 10 2.2 0.2 0.5 Pb high 2.2 10 17.6 0.4 Cd low 6.7 7 0.10 0.01 0.025 Cd high 3.6 10 0.27 0.01 Ni low 10.6 13 0.6 0.1 0.05 Ni high 2.9 18 2.5 0.1 Zn low 3.3 18 32.5 1.1 0.18 Zn high 3.4 15 106.0 3.6 Cr low 3.8 11 1.9 0.1 0.5 Crhigh 2.6 15 3.0 0.1 Mnlow 1.7 26 80 1 1.00 M n high 2.8 11 181 5 3 . 4 Conclusion The quality of the 'moss method' depends on the variability of the analyzed moss samples. A variation of 10 - 25% among subsamples, as reported in the present study, is similar to data reported in the literature (Thomas 1983). Subsample variation generally includes natural variation among different populations or different individuals, as well as the technical variation added through the analytical procedures. The inherent variation of each value reported in the following results section should be considered when drawing conclusion on the basis of 'moss method' data. 59 CHAPTER 4: RESULTS AND DISCUSSION FRASER VALLEY COLLECTION 1993 The regional distribution of atmospheric heavy metals, as indicated by the metal content in Isothecium stoloniferum is described. The metal distribution in the Fraser Valley is discussed in relation to natural parameters such as precipitation, elevation, and wind pattern. Anthropogenic influences in relation to the observed metal concentrations are discussed. Landuse, population density, industrial sources and traffic will be considered in detail. Finally the metal concentrations found in the Fraser Valley are compared to similar studies in other countries. 4.1 Regional distribution of metal content in mosses in 1993 Analysis of Isothecium stoloniferum for lead, cadmium, zinc and nickel revealed a distinct geographic distribution pattern. Differences in manganese and chromium concentration between the different locations were not as pronounced. In the following each metal is discussed in detail. 4.1.1 Lead Lead content in Isothecium stoloniferum from the Fraser Valley varied substantially throughout the study area. The overall average for the study area was 11.2 + 10.3 ppm/dry weight. Concentrations ranged from 1.8 ppm at Weaver Lake (sample site 47), to 47.5 ppm at Cypress Mountain (sample site 2). This spanned one of the largest concentration ranges observed in this study. The highest concentration being more than 60 20 times higher than the lowest concentration, was found only for lead and manganese. The regional distribution of lead concentrations in moss samples collected in 1993 is shown in Figure 4.1. The lead concentrations in moss samples from the western part of the study area, the GVRD (see Fig. 1.3) were significantly higher than those analyzed in mosses from the eastern regions of the Fraser Valley (Mann-Whitney-U statistics, p<0.001). Readings from the GVRD ranged between 3.9 ppm at Point Roberts (lib) and 47.5 ppm at Cypress Mountain (2), with an average of 19.9 ppm. The 14 highest concentrations from all samples were found in samples from the GVRD. The average concentration for the eastern valley was 5.3 ppm. The lowest concentration was recorded at Weaver Lake (Sample site 47/1.8 ppm), the highest at Sylvester Road (34/16.0 ppm). The 14 lowest values stem from eastern valley samples. The concentrations in the eastern area differed only slightly, compared to samples from the GVRD district. Here, extreme values, up to three times higher than any value from the eastern regions, were observed along the North Shore Mountains (2, 3b, 8a, 8b) and at Burnaby Lake (14a). Low values, comparable to those from the eastern region, were found in exposed sampling sites, close to the ocean, such as Bo wen Island (1), the University Endowment Lands (4a), Ladner Habour Park (11a), Point Roberts (lib) and Crescent Park (21). Within the GVRD, most of the less polluted sites were found in the southern areas, whereas higher values were found predominantly at sites in the northern reaches of the district. This north - south decline was not as distinct in the eastern Valley, where all values, independent of location, were relatively low. The sample at Galiano (Spec), collected as a regional background comparison, showed values similar to those found in the eastern Valley, 61 indicating that those sites were no more influenced through anthropogenic activity than the rather remote sampling site at Galiano island. 4.1.2. Cadmium Regional variation of cadmium concentration in Isothecium stoloniferum, samples is shown in Figure 4.2. The general distribution resembled that of lead (Fig. 4.1). The average of 0.28 + 0.16 ppm/diy weight, however, encompassed a much smaller range. The lowest value, 0.10 ppm, recorded for Lions Bay (Howe A) was ten times lower than the highest cadmium concentration, 0.97 ppm, found in South Burnaby at the Fraser River Park (14b). Although both the highest and the lowest overall cadmium concentration were found in moss samples from the GVRD, the average of 0.38 ± 0.19 ppm for the GVRD was significantly different from the eastern valley, reporting a mean of 0.22 ± 0.08 ppm (Mann-Whitney-U test, p<0.001). Within the GVRD, cadmium levels similar to lead levels, were high in samples from the North Shore mountains (8a, 8b, 12). Maximum levels, however, were found in mosses collected from the industrial areas in Richmond, at MacDonald Beach (4b/0.72 ppm), and Burnaby at Fraser River Park (14b/0.97 ppm), and at Trout Lake (9/0.68 ppm). Low levels, similar to the lead distribution, were reported for the exposed sites of Bowen Island (1), the University Endowment Lands (4a), Point Roberts (lib) and Crescent Park (21). The difference between southern and northern sampling sites was quite pronounced, and unlike the lead distribution, also found to some extent in the eastern valley. The background value of 0.10 at Galiano Island (Spec.) was slightly lower than most values in the eastern valley, 63 but the same as the lowest overall reading from the mainland at Lions Bay (Howe A/0.10 ppm). 4.1.3 Chromium The distribution of chromium concentrations found in Isothecium. stoloniferum samples from the Fraser Valley did not show as a distinct pattern (Fig. 4.3). The overall study area average for chromium was 1.0 + 0.6 ppm. The measured range of chromium concentrations was similar to the one reported for cadmium. The lowest concentration, 0.3 ppm, was measured in the moss taken from Rolley Lake (31), the highest, 3.3 ppm, in the sample from the Tamahi site (50) in Chilliwack. Another maximum value, 3.2 ppm, was found at Silver Lake (57). The observed concentration range spanned approximately ten times the concentration for the lowest sample. Both the sample sites featuring the lowest chromium concentration and the two sites reporting maximum values, were rather remote sites in the eastern valley. But high values were recorded also for sites in the GVRD. The sample from Trout Lake (9) measured 2.0 ppm and the sample from the Fraser River Park (14b) in South Burnaby read 2.2 ppm. The average of 1.0 ± 0.7 ppm for all samples from the eastern valley was not statistically different from the average of 1.0 + 0.2 ppm for samples from the GVRD. Some aspects of the regional distribution pattern contrasted the pattern observed for lead and cadmium concentration. Values in the North Shore Mountains were among the lowest recorded for the whole study area. Cypress Mountain (2/0.7 ppm), Capilano Dam (8a/0.77 ppm) and Seymour Dam (12/0.54 ppm) showed only slightly elevated chromium levels compared to the lowest overall value at Rolley Lake (31). The trend for low values at Bowen Island (1/0.37 ppm), the University 65 66 Endowment Lands (4a/0.78 ppm), and Point Roberts (1 lb/0.50 ppm), however, was persistent. The background sample from Galiano Island (Spec.) showed an elevated chromium level (1.5 ppm), compared to low values reported from several other locations throughout the study area. 4.1.4. Nickel Regional variation in nickel content in Isothecium. stoloniferum. was similar to the distribution found for lead and cadmium (Fig. 4.4). The total collection for the Fraser Valley study area showed an average value of 1.6 ± 0.7 ppm/dry weight. The concentration ranged from 0.6 ppm at Weaver Lake (47) to the extreme value of 4.3 ppm at the Fraser River Park (14b) in South Burnaby. The observed range, with the lowest concentration being about 10 times lower than the highest concenttation, was similar to the ranges for cadmium and chromium concentrations. The higher nickel concentrations in the GVRD (2.0 + 0.8 ppm), were proven to be significantly different from the lower concentrations observed in the eastern valley (1.2 + 0.5 ppm) by a Mann-Whitney-U test (p<0.001). Nickel concentration in moss samples collected along the North Shore Mountains showed slightly higher levels than those collected in the Burnaby/Port Moody area. The only extremely high value, however, was reported from South Burnaby: 4.3 ppm at the Fraser River Park. Other high values were found at MacDonald Beach (4b/3.1 ppm), Rocky Point Park (13b/2.7), and Trout Lake (9/2.3 ppm). Low nickel concentrations in samples from the GVRD were found at Pt. Roberts (1 lb/0.6 ppm) and Bowen Island (1/0.8 ppm). This pattern was similar to that observed for other metals. The 67 University Endowment lands (4a), showed a medium nickel level (1.5 ppm), which was considerably lower than any other site nearby. In the eastern valley concentrations were generally low, with a few outliers, showing high values: Langley City (24/2.5 ppm), Derby Reach (23/2.1 ppm) and Tamahi (50/2.8 ppm). In general, however, values measured in moss samples from the eastern valley were similar to those measured in moss from Galiano Island (Spec), which showed a nickel content of 1.0 ppm. 4.1.5. Zinc The regional distribution pattern of zinc concentration in Isothecium stoloniferum. was similar to that of lead, cadmium, and nickel (Fig. 4.5). The overall average of 39.4 + 18.0 ppm/dry weight, encompassed the least range observed for any metal under consideration in this study. The lowest value, 22.1 ppm, reported from Silver Lake (59) was only five times lower than the highest value, 99.0 ppm, reported from the Fraser River Park (14b). Zinc concentrations in samples from the GVRD, averaging 52.8 + 19.6 ppm were significantly higher than concentrations measured in samples from the eastern valley, averaging at 29.3 + 5.9 ppm (Mann-Whitney-U statistics, p<0.001). Zinc concentrations within the GVRD showed a similar distribution pattern to cadmium (Fig. 4.2). Extreme values were reported for both metals from locations in the industrial areas of Burnaby and Richmond. Aside from the maximum value at the Fraser River Park (14b), other extreme high concentrations were found at Burnaby Lake (14a/ 92.9 ppm), Rocky Point Park (13b/85.3 ppm), MacDonald Beach (4b/ 84.8 ppm), and at Richmond Nature Park (10/78.3 ppm). Zinc concentration in samples from the North Shore were 69 high, but not extreme. Low zinc concentrations were found in Isothecium stoloniferum from Point Roberts (lib) and Bowen Island (1). Similar to the nickel pattern, the University Endowment Lands (4a/39.6 ppm) showed lower levels than most of the surrounding sites, but elevated when compared to the former (lib, 1). Medium zinc concentration, 40.0 ppm, was recorded also for the Stanley Park site (3a). Lower zinc content was observed in samples from the southern sites in the GVRD, a trend also observed in other metals (Fig. 4.1 - 4.6). In the eastern valley most samples exhibited low zinc levels. No extreme or high values, were recorded and medium levels were measured only at five sites (57, 55, 54, 45, 37). The background measurement from Galiano Island (Spec/28.1 ppm) was similar to values measured throughout the eastern valley. 4.1.6 Manganese Manganese concentrations in samples of Isothecium. stoloniferum did not show a distinct regional distribution pattern (Fig. 4.6). The average value of 178 + 145 encompassed a large range, similar to that observed for lead concentration. The lowest concentration, 31 ppm at Bridal Veil Falls (53), was more than 20 times lower than the highest value, 824 ppm, measured at the nearby Foley Creek site (54). Manganese concentrations in moss samples from the GVRD district were similar to those in samples from the eastern valley. Both areas showed an average manganese concentration of 180 ppm. High manganese concentrations were measured in areas, where other metals showed high concentration as well. Burnaby Lake (14a/324 ppm) and Richmond Nature Park (10/387 ppm) represented high levels in samples from industrial areas, where as 71 Lighthouse Park (3b/409 ppm), Lynn Canyon (8b/328 ppm), and Seymour dam (12/347 ppm) represent typical high values found along the North Shore mountains. Contrasting to these, extremely low values were found at sample locations, which usually feature high levels, such as Cypress Mountain (2/97 ppm) and the Fraser River Park (14b/84). The eastern valley was characterized by a majority of samples with low and medium manganese concentrations. Three samples, however, showed high values (42, 33, 31), and two samples showed extremely high readings: the one collected at Foley Creek (54/824 ppm), and the one from Jones Lake (57/702 ppm). The moss sample from Galiano Island (Spec/104 ppm) was slightly higher than most of the low samples from the eastern valley. 4.2 Metal index Lead, cadmium, nickel and chromium concentration in Isothecium stoloniferum showed a highly correlated pattern (Spearman-rank-correlation, p<0.001). The statistical results are reported in Appendix A (Tab. A3). The general distribution for these four metals is shown in Figure 4.7, which is based on a general metal index (see Section 2.2.6). An index value of 16 indicates that, for all four metals, this site showed metal concentrations within the top 25% of all sample sites. A reading of 4, in contrast, indicates that the particular sample features concentrations in the lower 25% for all four metals. High index values (14-16) were prominent in the GVRD. Samples from the Northshore mountains in North and West Vancouver (3b, 2, 8a, 8b, 12, 17), and from the Burnaby/Port Moody area (9, 13a, 13d, 3b, 19, 14a), as well as samples from Richmond 73 and Delta (4b, 10, 11a) and from Downtown Vancouver (3a) feature a generally high metal content. Only one very high index value was reported for the eastern valley. The high metal index at Sylvester road (34), was largely related to high lead and cadmium concentration (see Fig. 4.1, 4.2). Medium index values (11-13), were found mainly at the GVRD - Eastern valley border. This might reflect less local metal pollution in these areas and a trend towards partial eastward distribution of particulate matter from areas with a high metal loading. The medium index at Mills Lake (37) in Clearbrook, however, seems separated from the general eastward directed plume. The elevated metal index, when compared to surrounding sites, was largely related to increased concentration of lead, nickel, and zinc (see Fig. 4.1, 4.4, 4.5.). Low (8-10) and extremely low (4-7) index values were found throughout the eastern valley. The exposed sites in the GVRD, namely Bowen Island (1), the University Endowment Lands (4a), Point Roberts (lib) and Crescent Park (21) also feature low or extremely low index values. The background site at Galiano Island also yielded a very low metal index, comparable to sites in the eastern valley. 75 4.3 Relation to Natural Factors 4.3.1 Precipitation The influence of precipitation on metal concentration in Isothecium stoloniferum is not clear. Neither correlation of metal concentrations to the general precipitation for the whole study area (Fig. A7/Appendix A), nor to the detailed Vancouver area precipitation pattern (Fig. A8/Appendix A) revealed a distinct trend. A positive relationship was found only between manganese concentration and precipitation for the whole study area (Spearman rank correlation, p<0.05). This, however, did not repeat in the more detailed investigation for the Vancouver area. Negative correlation to precipitation was found for chromium concentration. This was observed in both tests, for the complete study area and for the Vancouver area (Spearman rank correlation, p<0.05). Lower chromium accumulation with increasing precipitation might result from less soilborne, locally produced chromium containing particulates (see Section 1.3.4.3), in areas of high precipitation. Statistical results are shown in Appendix A (Tab. A3). Although statistical proof is not available, a trend of increased metal concentration in mosses from locations with high precipitation was apparent. Figure 4.8 shows high precipitation levels in the North Shore mountains, where mosses feature high metal content (Fig. 4.7). Increased metal levels might be related to increased deposition through precipitation. Local anthropogenic emission sources were few, if not absent in North and West Vancouver, and therefore could not be contributing significantly to the metal loading. High metal concentrations, on the other hand, were reported also from areas with lower precipitation. Sites in Richmond, Delta and the Burnaby/Port Moody area featured 76 > 1600 mm I 1200 mm -1600 mm Fig. 4 . 8 : Annual precipitation in the Fraser Valley (Source: Atmospheric Canada, 1993) a high metal index, but comparatively little precipitation. Moss collected at the Fraser River Park site (14b), for example, featured extreme concentration of cadmium, nickel, and zinc, but precipitation levels were only medium (Fig. 4.8). Here local emission sources, rather than high precipitation, were the main cause for high metal readings in moss samples. A general trend of increased heavy metal accumulation in moss tissue collected from sites with high precipitation has been suggested by many studies (Ruehling & Tyler 1968, 1969, 1971, Groet 1976, Grodzinska 1978, Thomas & Herrmann 1980). In most cases, however, the precipitation effect is obliterated by local long and short range transport patterns and anthropogenic emissions. Statistical proof for this trend has been provided only once. Ruehling & Tyler (1969) report a significant 77 difference between elevated lead levels in samples from humid ridges compared to those in samples from drier lowland areas. As the difference in metal concentration proved significant only for lead, but not for any other metal examined in their study, it might be concluded that precipitation has the strongest influence on lead deposition and uptake This was supported by Groet (1976), who showed that lead deposition is very susceptible to precipitation. The results of the present study were consistent with this hypothesis. Lead concentration in samples from the humid North Shore mountains, were extreme. The other metals also showed high values at these sites, but not at the same maximum levels found for lead. 4.3.2 Elevation Elevation of the sampling sites varied from near sealevel at sites such as Point Roberts (lib), MacDonald Beach (4b), Richmond Nature Park (10), Fraser River Park (14b) and many others to an altitude over 400 m in mountainous sites such as Cypress Mountain (2), Burke Mountain (22), Sumas Mountain (40) and Jones Lake (57). No significant positive correlation was found between elevation and metal concentration (Spearman rank correlation). Sample site elevation and statistical results are given in Appendix A (Tab. A2/A3). The Spearman rank test, however, did reveal a significant correlation between elevation and precipitation (p<0.001). This underlines that, although higher altitude sites receive more precipitation and show a trend towards increased metal deposition, the effect is obliterated by other factors as discussed in the previous section. A negative correlation between elevation and metal accumulation was found for nickel and 78 chromium. At higher altitude, nickel and chromium concentrations were lower, compared to sites at lower elevation, where nickel and chromium concentrations were higher (Spearman rank correlation, p<0.05). For chromium this reflects the negative relationship observed for precipitation. Both chromium and nickel are prominent in soilborne dust. From the data, there seems to be a tendency that soilborne dust was less common at higher elevation. Sites at higher altitude might be influenced in this way in addition to increased precipitation. Sites at higher elevation (200 - 700 m) are typically characterized by a dense, moist forest with abundant understory. Dust generation in such environments is expected to be minimal. In addition, many of the low elevation sites featured high levels of chromium and especially nickel that are related to human activity. The low elevation site at the Fraser River Park site (14b/0 m) featured extreme levels of nickel and high levels of chromium (Fig. 4.3/4.4). Similarly, high levels of nickel and chromium at low elevation sites such as Trout Lake (9/30 m), Rocky Point Park (13b/0 m), and MacDonald Beach (4b/0 m), were more likely to be related to local emission sources, than to the low elevation. 4.3.3 Wind Pattern Local - air movement is one of the main factors determining the distribution of particulates (Chamberlain 1986). Goodman & Roberts (1971) reported up to 10 times higher heavy metals concentration in the moss Hypnum cupressiforme collected downwind from an industrial centre, compared to samples collected from upwind locations. 79 In the Fraser Valley, regional surface winds are mainly from the east or south east, but are contrasted by a second maximum of northwesterly winds. A detailed discussion of the local air movement is given in Section 1.4.3. High metal readings in the GVRD were related, in part, to this contrasting air movement. The locally produced particulates were contained in the ambient air over the western region of the study. An extensive eastward fanning of the particulate plume was not observed. The general metal index (Fig. 4.7) showed continuous low metal concentrations in samples collected east of Langley (24) and Golden Ears Park (30). High metal loadings in the Burnaby/Port Moody area were mostly a result of local emission sources, but the effect was augmented by rather poor ventilation, preventing extensive pollution dispersal. The more exposed sites along the coast, in contrast, showed low metal readings, as incoming northwesterly winds dispersed particulate levels in the ambient air quickly. The high metal loadings in samples from the North Shore (3b, 3a, 8a, 8b, 12) might be the result of particulate transport from industrial areas in the valley bottom. Surface winds from the southeast and the mountain/valley breeze could be considered as import factors of pollutant translocation to the North Shore Mountains. 80 4.4 Relation to Anthropogenic Factors 4.4.1 Population Population density in the immediate surroundings of the sample sites is displayed in Figure 4.9. Sites in the GVRD generally featured high population whereas population density in the eastern valley was low. Correspondingly, concentrations of lead, cadmium, nickel, and zinc were significantly higher in mosses collected from the GVRD, compared to those collected from the eastern valley (see Section 4.1). Sample sites in the eastern valley, which did show higher population density, also featured a higher metal index (Fig. 4.7). This was most apparent at Mills Lake (37) and Derby Reach (23). This relationship, however, was not valid in both directions. Other sites featured a high metal index but little population. One example was Sylvester Road (34), with a high metal index, but a 0 10 20 Km Fig. 4.9: Population density in 0.5 -5 km rings around the Fraser Valley Collection sites (Source: Statistics Canada, Census data 1991). 81 low population density. Metal concentration at these sites might be related to factors other than population density. A Spearman rank correlation test showed an overall significant relationship between population density and lead, cadmium, chromium, nickel, and zinc (p<0.05). No correlation was found for manganese. Population data and statistical results are given in Appendix A (Tab. A2/A3). No account of statistical correlation of population density to metal concentration in mosses, was found in the literature. Many studies, however, do report increasing metal levels with decreasing distances from a major metropolitan center (Groet 1976, Ruehling & Tyler 1984, 1987, Schunke & Thomas 1983). Population density by itself, does not contribute to increased metal loadings in the atmosphere. High population density usually coincides with high industrial activity and/or high traffic volume (Thomas & Herrmann 1980). For the GVRD district highest population density was reported from sites in the Burnaby/Port Moody area, such as Trout Lake (9), Capitol Hill (13a), and Burnaby Lake (14a) and from downtown Vancouver, at Stanley Park (3a). At these sites, industrial activity is prominent (see Section 4.4.3) and traffic volume is expected to be high. 4.4.2 Landuse Landuse in general is a major factor determining the particulate emissions. Remote areas, are less exposed to metal deposition compared to rural areas, and these are substantially less exposed than urban areas (Davidson 1986). Thomas & Herrmann (1980) showed a general trend towards lower metal concentration in moss samples from agricultural areas, 82 compared to those from more industrial areas. The landuse in the Fraser Valley is characterized by a decline of urbanization and a subsequent increase of agriculture along a west-east gradient (Moore, 1990). The GVRD, in the west of the study area, is mostly classified as urban area, with some agriculture in Richmond and Delta. Urban activities, such as industry, traffic, fossil fuel combustion for spaceheating, etc. were reflected in the high metal concentrations reported for mosses collected in the GVRD (Fig. 4.7). In the eastern Valley, the landuse of municipalities of Langley, Pitt Meadows, Maple Ridge, Mission, Matsqui, Abbotsford, is characterized by approximately equal use of both agricultural and urban activities. The metal index map showed mostly low and medium metal concentrations in mosses collected from these areas. Moss samples collected in the very east of the study areas, at sites east of Abbotsford and Mission showed mostly very low, and low, metal indexes. This was reflected in a landuse pattern dominated by agriculture and forestry. 4.4.3 Industrial Activity Industrial activity contributes a substantial amount of particulate matter into the ambient air of the Fraser Valley (GVRD 1993b). Figures 4.10-4.12 show the location of industrial operations in the Valley that either hold an emission permit for specific heavy metals or are classified as metal emission sources in the 'Environment Canada toxics model' (Environment Canada 1995). Most emission sources were located within the GVRD. Only a few are identified for the eastern valley. This corresponded to the significant difference in lead, cadmium, nickel, and zinc concentrations in mosses from the GVRD area, compared to those collected from the eastern valley (Fig. 4.7). 83 Pb • Cd Fig. 4.10: Lead and cadmium emissions in the Fraser Valley. Emission sources 1-15 are based on Environment Canada's toxic model, 1, 16-40 are based on GVRD emission permit data (see Section 2.2.8). Fig. 4.11: Chromium and nickel emissions in the Fraser Valley. Emission sources 1-15 are based on Environment Canada's toxic model, 1, 16-40 are based on GVRD emission permit data (see Section 2.2.8). 84 Fig. 4 . 1 2 : Zinc and manganese emissions in the Fraser Valley. Emission sources 1-15 are based on Environment Canada's toxic model, 1, 16-40 are based on GVRD emission permit data (see Section 2.2.8). The general trend of decreasing metal concentrations in mosses with increasing distance from industrial sources has been demonstrated in studies for various regions (Ruehling & Tyler 1969, 1984, Groet 1976, Thomas & Herrmann 1980, Herrman 1970, Herrman & Huebner 1984, Herpin 1994). Location of particular point sources, however, can be only partially related to metal concentration in specific moss samples. Industrial activity at the east end of Burrard Inlet, in North Burnaby and Port Moody, was clearly responsible for the high metal readings at the sample locations of Capitol Hill (13a) and Rocky Point Park (13b). The extremely high metal readings observed for the Fraser River Park (14b) were also most likely due to local emission sources. Most point sources, however, contribute to the general heavy metal loading in the ambient air, which would affect all 85 moss samples from the area not only those from the nearest sample site. The large number of emission sources located along the South Arm of the Fraser River and on Annacis Island (1, 2, 6, 29, 40, 27, 30), for example, were not reflected in locally high metal content of moss tissue. Mosses from the Delta sample site (15) did not feature maximum metal readings as expected, but only a medium metal index. The few point sources located in the eastern valley also did not cause high metal concentration in mosses from any particular location. The high metal index at the UBC research forest (26) was based primarily upon medium lead and cadmium levels. Nearby point source 4 emits lead, chromium, and nickel and might be only partially responsible for the medium metal index found for this site. In general, it can be said that metal concentrations were related to the presence of industrial sources, but an attribution of locally high metal levels to any particular source was in most cases not feasible. To determine the effect of a known or suspected point source a different sampling scheme has to be employed (Kansanen & Venetraara 1991, Gignac 1986). General emissions from industrial point sources, such as particulates, S0 2, NO x , VOC, and CO have been modelled by the GVRD (GVRD 1993b) in the 'GVRD gridded emission model'. The model data and statistical analysis is provided and explained in detail in Appendix D. Modelled emissions showed significant correlation with matched moss samples, in several cases. Particulate emissions from point sources, identified in the model, were con-elated only with lead concenttation in moss samples of the present study (Spearman rank con-elation, p<0.05). The model estimated highest emission in the Vancouver Harbour area, as well as in Delta/Richmond and South Bumaby/New Westminster. Forty-three 86 percent of all particulate emissions from the GVRD were estimated to originate from bulk shipping and terminals and with an additional 25% from wood product processes, such as sawmills (Fig. D3, Appendix D). Particulates originating from those sources were not expected to have high heavy metal content. The correlation to lead levels in moss samples was likely to be significant due to other emission sources in those areas. The correlation of other pollutants, such as SOx, VOC, and CO, to the metal concentration in moss samples, showed more meaningful relations. SOx and VOC emissions were significantly correlated to lead, chromium, nickel, and zinc concentration in moss samples (Tab. D5, Appendix D). CO emissions were significantly correlated to the lead and nickel levels in moss samples. SOx, VOC, and CO emissions were modelled to be highest in South Burnaby, the Burnaby/Port Moody area, Richmond and Delta. Sources emitting high levels of SOx, VOC, and CO are more likely to emit heavy metal containing particulates, than those sources that emit high levels of particulates in general. Sixty percent of the SOx emissions in the GVRD were from petroleum refining. An additional 33% originated from non-metallic mineral processing, mostly cement operations (Fig. D3). Both processes were also classified as metal emission sources (Pacyna 1986a). VOC emission was also mostly from petroleum refining. Modelled CO emissions were mostly based on wood and paper processes. This by itself did not provide an explanation for the significant correlation to lead and nickel concentrations in the moss samples. However, 9% of all CO emissions were based on metal foundries and metal fabrication processes. This is the largest fraction of any pollutant attributed to metal foundries and metal fabrication (Fig. D3). Although outnumbered by other processes these metal emitting processes might be responsible for the con-elation of lead and nickel 87 to CO emission. A general agreement between the 'GVRD gridded emission model' and the metal concentrations in moss samples of the present study cannot be denied, but more detailed information on the individual emission sources is necessary to verify this trend. 4.4.4 Traffic - Mobile Sources Automotive traffic is a source for many heavy metals, especially manganese from the additive MMT (Methylcyclopentadienyl manganese tricarbonyl) and zinc from tire abrasion (Pacyna 1986a, Loranger et al. 1994). This, however, was reflected only partially in the moss analysis of the present study. The 'GVRD gridded emission model' identified NO x, VOC, SOx, CO, and road dust emissions from motor vehicles, based on traffic volume (GVRD 1994b). Al l of the modeled emissions were correlated significantly to lead, cadmium, chromium, nickel, and zinc concenttation in moss samples from the same area (Spearman rank correlation, p<0.05). Manganese did not show any relevant correlation. Results of the statistical test are given in Appendix D (Tab. D5). The observed correlations, however, need to be examined with caution. Areas with high traffic volume were the same areas which feature high industrial activity and a dense population. In Burnaby, Richmond, and Delta, various factors, not only traffic, might contribute to the metal loading in the ambient air. The failure of manganese to correlate to modelled traffic emissions might be related to the absence of other contributing factors. Although manganese is emitted in car exhaust (Brault et al. 1994, Loranger et al. 1994), it does not contribute enough to the ambient air to be reflected in the moss data. This supported the hypothesis that the correlation between traffic emissions and metal 88 concentration in mosses is, in fact, only partially related to traffic. This is also supported by the finding that no elevated metal levels in mosses were found in relation to Highway #1, which runs along the Fraser River from Surrey to Hope. Particulate metal emissions from road traffic affect only the immediate environment directly. At a distance of greater than 100m metal concentrations in moss tissues were found to be similar to general background levels and affected by a variety of emission sources, not the road alone (Ruehling & Tyler 1968). In the present study all samples were taken at least 500 m away from any major road. In order to determine the direct effect of automotive traffic on metal concentrations, a sampling scheme along a transect perpendicular to a road needs to be employed. 4.5 Literature Comparison The Fraser Valley generally featured slightly lower moss metal levels than Germany, Southwestern Sweden and Poland (Fig. 4.13) where similar studies have been carried out recently (Herpin 1994, Ruehling et al. 1987, Grodzinska et al. 1990). In many cases Fraser Valley levels were comparable to background values reported from Greenland, Spitsbergen and Iceland (Grodzinska & Godzik 1991, Ruehling et al. 1987). For a meaningful comparison, however, it is essential to compare the GVRD area and the eastern valley separately to the European studies. The metal values obtained from samples taken within the GVRD were generally in the same concentration range as those from western industrialized countries. (Ruehling et al. 1987, Herpin 1994). Southwestern 89 90 BO 70 60 CD CD s 50 £-TJ 40 E Q . 30 20 10 0 Lead j I P i % i i « 1 1 m 1 A 1 —E83S3—i—ES I , m , Eil , — i — a m CD s 5 o CD E) CO ^ CO : co i to a . CO (D co =L Chromium _ I 1 £5 i , fc3si , EsSa , i l l PH - i i " n o m o 5 < $ -W ID -*• X i CO 3 O - CO p 3 x co a> =^ CU CD (D — CO -< Fig. 4.13: Comparison of results for lead, cadmium and chromium from the Fraser Valley 1993 collection from the present study to recent moss method studies from Europe. The error bars indicate standard deviation, if reported in literature. Species used are: Germany - mix, predominantly Pleurozium schreberi. Sweden, Iceland, Poland - Pleurozium schreberi and Hylocomium splendens. Greenland - mix, incl.the above and Drepanocladus uncinatus. Spitsbergen - Hylocomium splendens (Sources: Herpin 1994, Ruehling et. al 1987, Grodzinska et al. 1989, Grodzinska & Godzik 1991). 90 7 Nickel Fig. 4.13a: Comparison of results for nickel and zinc from the Fraser Valley 1993 collection from the present study to recent moss method studies from Europe. The error bars indicate standard deviation, if reported in literature. Species used are: Germany - mix, predominantly Pleurozium schreberi. Sweden, Iceland, Poland - Pleurozium schreberi and Hylocomium splendens. Greenland - mix, incl.the above and Drepanocladus uncinatus. Spitsbergen -Hylocomium splendens (Sources: Herpin 1994, Ruehling et. al 1987, Grodzinska et al. 1989, Grodzinska & Godzik 1991). 90a Sweden and Germany face similar problems to the GVRD, regarding population density, traffic volume, and emissions from industrial activity. Poland is a typical example for an eastern European industrialized country battling pollution problems, with far less advanced technology (Grodzinska et al. 1990). In addition to local sources, long range transport from other industrialized areas in central and eastern Europe, contribute to metal loadings at any site in Europe (Ruehling et al. 1987). Similarly, long-range transport from sources in the United States could affect the Fraser Valley, but this has not yet been confirmed. When considering these trends it is important to keep in mind that other studies have utilized other species of moss. Interspecies variation can affect metal loadings significantly (see Section 1.2.4.4) and comparisons are based on trends only. Lead content in moss samples from the GVRD was slightly higher than the average lead content in moss from Germany and slightly lower than the average lead content for moss from south western Sweden. Reduction of lead levels in gasoline, use of unleaded fuel and implementation of modem industrial filter technology in both countries were similar to pollution prevention measures in Canada (see Section 1.3.4.1) (Ruehling et al. 1987). Lead levels in areas with little anthropogenic influence, such as Greenland, Spitsbergen and Iceland showed low values, comparable to those found in the eastern Fraser Valley, outside the GVRD. Extreme values in Poland might be related to the use of leaded gasoline. Cadmium in moss samples from the GVRD district showed similar levels to those reported for Southwestern Sweden and Germany, whereas the eastern Fraser Valley values were more similar to background levels from Iceland and Greenland. Differences 91 between the Fraser Valley, Sweden, Germany, Greenland, and Iceland were only minor, compared to the extreme levels reported for Poland and Spitsbergen. The extreme cadmium values in Poland might be related to abundant heavy industry (Grodzinska et al. 1990) and coal combustion for space heating. Herpin (1994) reported elevated cadmium level for all states in former East Germany, where coal based space heating systems are also very common. The high cadmium values in Spitsbergen were attributed to large amounts of soilborne, windblown dust, in these sparsely vegetated areas (Grodzinska & Godzik 1991). However, the possibility of an artifact related to poor analytical accuracy, cannot be excluded. Spitsbergen and Poland were both surveyed by the same laboratory, using Pyrex glassware and only distilled water for their analysis. Chromium levels in mosses from the Fraser Valley did not show the typical west-east gradient observed for other metals. The Fraser Valley, in general, featured lower chromium readings than any other recent study, only slightly lower than Germany and Sweden, but significantly lower than Poland and surprisingly significantly lower than Greenland and Iceland. This suggests, that chromium emissions from industrial sources such as stainless steel processing, common in Germany, were negligible. Emissions and deposition from windblown, geogenic material (Wedepohl 1991), in contrast, might contribute significantly to the atmospheric chromium loadings (Schunke & Thomas 1983). Nickel levels, in both areas, the GVRD and the eastern valley, were lower than nickel levels in European mosses. Only moss samples from Iceland showed low nickel concentrations comparable to the eastern Fraser Valley. This pattern was similar, and 92 probably related to the chromium results. Lack of major industrial nickel sources in British Columbia, such as stainless steel manufacturing, accounted for relatively low nickel levels. A dense vegetation cover at most sampling sites prevented nickel pollution from soilborne dust. Nickel emission from oil combustion for space heating accounted for most of the difference between the GVRD and the eastern Valley. In Germany and Poland the stainless steel industry accounted for most of the nickel emissions. In Poland, extensive coal and oil combustion for space heating added additional nickel to the atmosphere. Windblown dust in sparsely vegetated areas such as Greenland, Spitsbergen and Iceland was suspected to be the main source for nickel in those remote areas. Nickel levels in Iceland, however, were as low as in the Fraser Valley, which could be related to the specific mineral composition of surface materials in Iceland. Zinc concentrations in mosses from the GVRD were comparable to those in mosses from Southwestern Sweden and Germany, which probably experience similar or even higher traffic density and industrial structure. Higher values in Poland were most likely related to coal combustion, the principal heat source. Zinc levels in mosses from the eastern valley were similar to the background values reported for Iceland and Spitsbergen and lower than those reported for Greenland. Manganese data were not available in the literature. In most survey studies similar problems to the present study were observed. As a consequence there has been a failure to establish a clear distribution pattern (Folkeson 1981, Rinne & Barclay-Estrup 1980, Barclay-Estrup & Rinne 1979) 93 4.5 Fraser Val ley Conclusion Heavy metal levels in the ambient air of the Fraser Valley were related to natural and anthropogenic factors. Lead, cadmium, nickel, zinc, and to a lesser extent chromium and manganese concentrations in Isothecium stoloniferum were generally high in areas characterized by industrial activity, high population density and traffic volume. A distinct air movement and precipitation pattern, related to the coastal and mountainous location of the study area, might account for metal deposition distant from the emission sources. North-west directed pollutant transport, caused by mountain-valley breezes and north-west directed surface winds, result in high metal levels in the North Shore mountains, adjacent to the Vancouver area. High precipitation at higher altitudes might have increased metal deposition and accumulation in mosses at these sites. An extensive eastward pollutant transport was not observed. The predominant southeasterly winds were contrasted by a second maximum of northwesterly winds confining metal pollutants to the GVRD. A diurnal land/sea breeze, apparent on calm days, might account for additional air circulation over the western valley. Both air movements might be the reason for confinement of most pollutants to the GVRD where emission sources are most abundant. Pollutant levels were generally high in the GVRD, but eastern areas further up the valley were only slightly affected. Metal readings from mosses from the eastern valley were generally comparable to literature values from remote areas, such as Greenland, Spitsbergen, and Iceland. The metal concentrations in mosses from the GVRD were comparable to other industrialized study areas, such as Germany and Southwestern Sweden. 94 CHAPTER 5: RESULTS AND DISCUSSION HERBARIUM COLLECTION Analysis of herbarium specimens of Isothecium stoloniferum. revealed historical distribution patterns for lead, cadmium, chromium, nickel, zinc, and manganese. For 1960 - 1966 the complete study area was represented, for 1975 - 1980 focus was on the eastern regions, outside the GVRD district. Three sites (Bridal Veil Falls, UBC Research Forest, University Endowment Lands (UEL)), were investigated in more detail, showing a time line of metal content in moss samples from the 1960's until today. The general trend in historical changes of atmospheric metals was demonsfrated by comparing results from the herbarium analysis to those obtained from samples collected in 1993 for this study. Finally, the relationships of these findings to changes in industrial activity, fossil fuel combustion and chemical composition of gasoline additives illustrated the impact of anthropogenic activity on the moss metal content. 5.1 Regional Distribution of Heavy Metals in Herbarium samples 5.1.1 Regional distribution of Heavy Metals in 1960 -1966 The regional distribution of element content in Isothecium stoloniferum collected between 1960 and 1966 is displayed in Figure 5.1 to Figure 5.6. Moss samples collected in the Greater Vancouver Regional District (see Fig. 1.3), showed a significantly higher lead, cadmium and zinc content, than samples taken from the eastern regions of the Valley, outside the GVRD (Mann-Whitney-U test, p<0.05). Manganese showed a 95 distinctively higher concentration in the eastern regions (Mann-Whitney-U test, p<0.05), whereas chromium and nickel failed to show a difference between the two areas. The typical west-east gradient, as observed for lead, cadmium and zinc was related to urbanization,. traffic volume and industrial activity, as outlined in Section 4.4. The distribution of metals was similar to those observed for the samples collected in 1993 (Fig. 4.1 - 4.6). Although population density and traffic volume was lower in the 1960's, and industrial activity was different from today, it has been always the Greater Vancouver area that was more exposed to those air pollution generating processes, when compared to the more rural countryside in the eastern stretches of the Lower Fraser Valley. High levels of manganese in the eastern area might be related to extensive slash burning, after clear cut logging, a landuse activity prominent on the forested mountain slopes bordering the eastern regions of the study area. One might also speculate, that the low levels of manganese in the GVRD area, where other heavy metals are high, relate to the fact that manganese can participate in the ion exchange reaction. Ion exchange of manganese with metals with high binding affinities has been proven in laboratory experiments (Ruehling & Tyler 1971). To verify application of these findings in field situations a specifically designed experimental approach is necessary. The uniform distribution of chromium and nickel throughout the valley could be related to the abundance of those elements in mineral matter (see Section 1.3.4.3. & 1.3.4.4.). Contamination of the herbarium samples with soil is not unlikely, as these were not collected for a biomonitoring study, therefore not treated with required precaution to avoid input of foreign material. 96 Pb (ppm) Fig. 5.1: Lead concentration in herbarium specimen of Isothecium stoloniferum collected in 1960 - 66. Cd (ppm) Fig. 5.2 : Cadmium concentration in herbarium specimen of Isothecium stoloniferum collected in 1960 - 66. 97 Cr (ppm) 0 10 20Km Fig. 5.3: Chromium concentration in herbarium specimen o' isothecium stoloniferum collected in 1960 - 66. o 10 20 Km Fig. 5.4: Nickel concentration in herbarium specimen oi Isothecium stoloniferum collected in 1960 - 66. 98 Zn (ppm) Fig. 5.5: Zinc concentration in herbarium specimen of Isothecium stoloniferum collected in 1960 - 66. Fig. 5.6: Manganese concentration in herbarium specimen of Isothecium stoloniferum collected in 1960 - 66. 99 5.1.2 Regional Distribution of Heavy Metals in 1975 - 1980 The regional distribution of atmospheric metals accumulated in Isothecium stoloniferum during 1975 to 1980 is displayed in Fig. 5.7 - 5.12. Lead, cadmium and zinc were similar in distribution. Al l showed high values along the Fraser River and in Golden Ears Park, east of Pitt Lake. Nickel also showed high levels along the River, but no elevated values in the Golden Ears Park area. Chromium and manganese, did not show a distinct distribution pattern. High values along the Fraser River might be related partially to the west - east blowing winds, trapping pollutants from local sources in the area. More important, however, especially in regard to lead and zinc pollution, might be the route of Highway #1, which runs parallel to the Fraser River from Surrey to Hope at the eastern fringe of the study area. These high levels were contrasted by lower levels of lead, cadmium, nickel and zinc in four samples from the southeastern corner of the study area. These mosses, collected on the south facing slopes facing Chilliwack Lake were separated by a mountain ridge from the main airshed of the valley. High levels in Golden Ears Park might be the result of some long-range pollutant transport from the industrialized Port Moody/Burnaby area, in addition to increased deposition levels related to higher precipitation in this mountainous area. The outlier values for chromium and nickel in the samples from Jones Creek, the easternmost location, close to the Fraser river, were most likely a result of soil contamination. 100 101 Cr (ppm) Fig. 5.9: Chromium concentration in herbarium specimen of Isothecium stoloniferum collected in 1975 - 80. Ni (ppm) 1 Fig. 5.10: Nickel concentration in herbarium specimen of Isothecium stoloniferum collected in 1975 - 80. 102 Fig. 5.11: Zinc concentration in herbarium specimen of Isothecium stoloniferum. collected in 1975 - 80. Mn (ppm) Fig. 5.12: Manganese concentration in herbarium specimen of Isothecium stoloniferum. collected in 1975 - 80. 103 5.2 Changes over Time 5.2.1 Comparison of the Three Collection Periods (1960 -66,1975 - 80,1993) In order to compare changes in atmospheric metal levels since the 1960's, the mean values for metal concentrations from all three collection periods (1960 - 66, 1975 -80, 1993) were calculated, and are displayed in Fig. 5.13. Lead, cadmium, chromium, nickel, and zinc showed a considerable decrease over time. Manganese in contrast showed an increase since the 1960's. Collection means demonstrated clearly the general trends observed for changes in atmospheric metal loadings in the Fraser Valley. However, statistical differences between the three collection periods could not be established. Samples for each time period were taken from entirely different locations within the study area. Sample number for each time period was also variable. Fig. 5.13: Comparisons of metal concentrations for the three different collection times examined in the present study (values are means of all samples in the collection). 104 As illustrated in the regional studies, location can influence metal loadings substantially. If many samples were collected from the rural areas, the average value would be lower than if the average value were comprised mostly of samples from the higher polluted western area. In order to account for the geographical dependence of the metal values, samples from the historical collections were individually compared to samples taken in 1993 from the same or nearby locations. Limitations in the herbarium material made a comparison between the 1960 - 66 and the 1975 - 80 collection impossible. A list of these matched samples is given in Appendix B (Tab. B3/B4). Statistical comparison of metal readings from 1960 - 66 with those 'matched' values from the 1993 collection, supported the declining trend for lead, cadmium, chromium, nickel and zinc (Mann- Whitney-U statistics, p<0.05). The increasing manganese trend was also shown to be statistically significant (Mann-Whitney-U statistics, p<0.05). Higher manganese levels in 1993 were observed mostly at sites in the GVRD, mainly located in the North Shore Mountains. A comparison between the 1960 - 1966 samples and the matched samples from the 1993 collection is displayed in Fig. 5.14. The comparison of metal readings from samples collected in 1975 - 1980 to metal values of samples collected from similar sites in 1993 is shown in Fig. 5.15. Metal concentrations in moss samples from 1975 - 1980 were shown to be significantly higher only for lead and nickel (Mann-Whitney-U statistics, p<0.02). Changes in cadmium, chromium and manganese, were statistically not significant. Zinc levels showed a slight, but significant increase in 'matched' samples from 1993 (Mann-Whitney-U statistics, p<0.05). 105 Fig. 5 . 1 4 : Comparison of metal concentrations (Pb, Cd, Cr) in samples from the 1960 - 66 collection to metal concentrations from moss samples from matched sites from the Fraser Valley 1993 collection (p value under legend indicates results from Mann-Whitney-U-Statistics. Averages were calculated when the same 1993 sample was matched to various samples from the herbarium collection (for: Bowen Isl., Capilano, Uel, UBC Research, Cheam, & Harrison, for values see Appendix B, Tab. B3). 106 7 Nickel Fig. 5.14a: Comparison of metal concentrations (Ni, Zn, Mn) in samples from the 1960 - 66 collection to metal concentrations from moss samples from matched sites from the Fraser Valley 1993 collection (p value under legend indicates, results from Mann-Whitney-U-Statistics. Averages were calculated when the same 1993 sample was matched to various samples from the herbarium collection (for: Bowen Isl., Capilano, Uel, UBC Research, Cheam, & Harrison, for values see Appendix B, Tab. B3). 106a 80 Chromium H1975-80 • 1993 p=0.757 Fig. 5.15: Comparison of metal concentrations (Pb, Cd, Cr) in samples from the 1975 - 80 collection to metal concentrations from moss samples from matched sites from the Fraser Valley 1993 collection (p value under legend indicates results from Mann-Whitney-U-Statistics. Averages were calculated when the same 1993 sample was matched to various samples from the herbarium collection (for: Bridal Veil Falls & Chilliwack Lake., for values see Appendix B, Tab. B4). 107 250 200 .3 150 S E 100 50 A Fig. 5.15a: Comparison of metal concentrations (Ni, Zn, Mn) in samples from the 1975 - 80 collection to metal concentrations from moss samples from matched sites from the Fraser Valley 1993 collection (p value under legend indicates results from Mann-Whitney-U-Statistics. Averages were calculated when the same 1993 sample was matched to various samples from the herbarium collection (for: Bridal Veil Falls & Chilliwack Lake., for values see Appendix B, Tab. B4). 107a The downward trend for lead and nickel, as displayed in Figure 5.13, seems to be a continuous trend. Major changes in atmospheric lead and nickel loadings did occur even beyond the late 1970's. Those changes were incorporated, when the 1960's collection data were compared to the 1993 collection data. There was also an increase in manganese levels, although manganese changes between the late 1970's and 1993 were not as pronounced, as changes for lead and nickel (Fig. 5.15). The decline in atmospheric chromium was largely related to changes during the 1980's. There seem to be no differences between chromium readings from the 1960's versus those from the late 1970's. Cadmium levels, however, were drastically reduced between 1960 - 1966 and 1975 - 1980. No further change appeared to have occurred since then. Zinc, did not show a consistent trend. In the late 1970's it was greatly reduced compared to the 1960's, but a significant rise was then experienced during the 1980's and early 1990's, as seen in the comparison of the 1975 - 80 collection to the 'matched '1993 samples (Fig. 5.15). 5.2.2. Site - Time Line Analysis Heavy metal concentration of Isothecium. stoloniferum. collected at various time points since 1949 is displayed in Figure 5.16 for the University Endowment Lands (UEL)(26), in Figure 5.17 for the UBC Research Forest in Haney (42), and for Bridal Veil Falls (56) in Figure 5.18. In general these 'time line' trends were supportive of the trends observed, when the 1960-66, 1975-80, and the 1993 collection were compared. It has to be stressed, that these observations were trends without statistical verification, a consequence of limitations of the herbarium material. Al l three sites did show the same steep and continuous decline for lead and nickel that was reported from 108 Fig. 5.16: Site time line analysis for the University Endowment Lands (UEL) (26). Error bars indicate standard error, when more than one sample was analyzed for the data point (see Appendix B, Table B1). 109 Haney - Lead Haney - Cadmium Haney - Chromium Haney - Nickel Haney - Zinc Haney- Manganese Year Fig. 5.17: Site time line analysis for the UBC research forest (42). Error bars indicate standard error, when more than one sample was analyzed for the datapoint (see appendix B, Table Bl) . 110 Bridal Veil Falls - Chromium Bridal Veil Falls - Nickel Fig. 5.18: Site time line analysis for Bridal Veil Falls (56). Error bars indicate standard error, when more than one sample was analyzed for the data point (see Appendix B, Table BI). Ill the collection comparisons (Fig. 5.13). Levels were highest in samples collected during the 1960's and lowest in moss samples from 1993. Chromium levels also declined continuously, although less steeply, at all three sites. The decrease in cadmium and zinc concentration, and the manganese increase (Fig. 5.13), was supported only by the time -line trends at the University Endowment lands, and the UBC Research Forest. The collection comparison suggested that cadmium reduction did decline mainly during the late 1960's and early 1970's (Fig. 5.13, 5.14, 5.15). This was supported by the cadmium time line at the UBC research forest site, where the 1978 cadmium level was similar to the 1993 value (Fig. 5.17). Bridal Veil Falls exhibited similar cadmium levels throughout the whole time period. For the UEL location no sample was provided between the 1960's and 1987. In 1987, however the cadmium value was similar the 1993 value. The finding that chromium levels were predominantly dropping during 1980's, as seen in the collection comparison, was not suggested in of any site time - lines. Al l sites report continuous chromium decline since the 1960's. The observation of variable zinc levels, first decreasing from the 1960's to the late 1970's and then rising again, could also not be supported by any of the time lines. Instead, a steady decline was observed at the UEL site and at the UBC research forest, and no major changes were reported for Bridal Veil Falls, where levels were constant after a considerable decline in zinc levels between 1949 and 1964. Manganese levels were increasing over time in mosses from the UEL site and the UBC Research Forest. This is similar to the findings of the collection comparison. High manganese levels at the UBC Research Forest during the late 1950's early 1960's might be related to slash burning. At Bridal Veil Falls no increase of manganese concentration was observed. Here, trends for all metal in general were not as distinct as for the other 112 two sites. The reason for Bridal Veil Falls failing to show a distinct change overtime, for cadmium, zinc, and manganese might be related to the location of this sample site in the rural fringe of the eastern Fraser Valley. Remote from industrial sources and densely populated areas, metal loadings were, in general, lower (see Section 4.1) and might show less response to industrial changes. 5.4 Factors Influencing Historical Changes of Metal Concentration in Isothecium stoloniferum Particulate emissions in the Fraser Valley are related to point, area and mobile sources. In the following historical changes are examined: for point sources, in relation to industrial activity, for area sources through the example of space heating and for mobile sources by looking at changes in the chemical composition of gasoline. 5.4.1 Point Sources - Changes in Industrial Activity Manufacturing industry, in general, has experienced significant growth in the Fraser Valley since the 1960's (Department of Industrial Development, Trade, and Commerce 1966, Ministry of Economic Development 1986). Heavy industrial activity responsible for emitting large amounts of heavy metals, however, has been reduced in the urban areas during the late 1970's and 1980's. The British Columbia trade index lists 98 companies involved with sheet metal work in the lower Fraser Valley (Department of Industrial Development, Trade, and Commerce 1960). In 1994 this number has been reduced to 38 operating sheet metal businesses (B.C. Stats 1994). A prominent example 113 for the reduction of heavy industry in urban areas is the conversion of "Granville Island". This industrial area in False Creek, just immediately south of the Vancouver Downtown area has been successfully converted into a commercial and recreational area. Industrial production of metal products was common on Granville island until its redevelopment began in 1972 (Granville Island Office 1993). Relocation of metal fabricating industry, however, is only one of the reasons for the significant decline in metal concentrations in moss samples (Fig. 5.13). Another reason is the installment of effective emission control equipment. The installment and technological advance of cyclones, scrubbers, electrostatic precipitors and baghouses aided in reducing total particulate emission (GVRD 1993b, Licht 1988). The effectiveness can be judged partially by the decline of metal levels in moss tissue. 5.4.2 Area Sources - Changes in Space Heating Fuels Fossil fuel combustion for space heating accounts for a significant contribution of atmospheric particulates that contain metal residues (Pacyna 1986a). Wood, coal and oil were the main particulate emitting fuel sources used in the Fraser Valley in the 1960's. Wood burning includes the burning of sawdust. Wood combustion contributes 2.4 - 3.6 kg dust per tonne of wood burned (Pacyna 1986a) to particulate loadings in the ambient air. Higher particulate emissions are expected, when sawdust is burned, but no literature data are available. Wood combustion contributes mainly zinc to the atmosphere (58 g/t of burned wood), but also substantial amounts of cadmium (0.3 g/t), nickel (4.7 g/t) and lead (7 g/t). Emissions related to wood burning in fireplaces are generally slightly lower than the above values, which were estimated on the basis of wood combustion in a proper 114 wood stove (Pacyna 1986a). Particulate emission from coal combustion in residential coal fired units is estimated at 10 kg dust per tonne of coal burned. No particular metal can be related predominantly to coal combustion. Metals under consideration in the present study are all emitted to some extent by coal combustion. Emission factors for each tonne of coal combusted are: Lead (2.7 g), cadmium (0.2 g), chromium (4.2 g), nickel (5.1 g), and zinc (4.0 g) (Pacyna 1986a). Values for manganese were not available. Combustion of light fuel oil for residential space heating contributes 1.2 kg particulate matter per 10 000 litres oil. Nickel (27 g) is the dominant metal constituent in particulate emissions from oil furnaces. Other metals are also represented: lead (3.3 g), cadmium (0.3 g), chromium (1.1 g), and zinc (2.3 g) (Pacyna 1986a). In the Fraser Valley, space heating sources have undergone significant changes since the mid century (Fig. 5.19). This was partially reflected in the metal content of Isothecium, stoloniferum, collected at different time points within the past 50 years. In the 1950's oil, wood, and coal were used at equal amounts for heating residential units in British Columbia. Later in the 1950's and specially during the 1960's oil gained importance and over 50 % of all house hold were heated through oil furnaces. This might have accounted for the high nickel levels observed in moss samples taken from that time period (Fig. 5.13/5.14). In addition, cadmium, chromium, lead and zinc emission from oil combustion and to a lesser extent from wood and coal combustion contribute to the overall high metal concentration in the ambient air. 115 60 years - • - o i l -H- c o a l - ® - w o o d 60 years n a t u r a l g a s - s - e l e c t r i c i t y Fig. 5.19: Space heating fuels in British Columbia, 1953 - 1990 (compiled from B.C. Ministry of Energy, Mines and Resources 1994). 116 High zinc levels (Fig. 5.13). might have been due to some extent to wood combustion in earlier years. By the late 1960's, however, wood and coal as heating sources, were used in fewer than 10% of all households in British Columbia. Gas and electricity based heating systems became available, first replacing the wood and coal based units, and later during the 1970's and 1980's also gradually replacing the oil based heating systems. By 1990 fewer than 10% of all households were heated by oil, but over 50% utilized natural gas and 30% were heated by electricity both of which feature little or no particulate emissions. The trend to 'cleaner' space heating sources is reflected clearly in the general decline of metal emissions observed over the lower Fraser Valley. 5.4.3 Mobile Sources - Changes in Gasoline Composition Decreasing lead concentration and increasing manganese concentration in samples of Isothecium stoloniferum. since the mid century were related to changes in gasoline composition. Prior to 1972, tetraethyl lead or tetramethyl lead was used as an antiknock additive in all gasolines sold in Canada. In 1972, unleaded gasoline was introduced to the Canadian market to meet the needs of new catalytic converter equipped automobiles (Lafleur 1994). Sales of leaded gasoline were continuously dropping, substituted by sales of unleaded gasoline, which became mandatory by the end of 1990 (Fig. 5.20). Studies from the 1960's found elevated lead levels in mosses and higher plants growing adjacent to major highways. Lead levels decreased with increasing distance to the traffic route. (Ruehling & Tyler 1968, Cannon & Bowles 1962). Higher lead levels in soils close to highways and in blood from children residing in areas with high traffic volume, have also been reported-(Joselow et al. 1978). These findings confirmed the general influence of 117 35.0 1975 1978 1981 1984 1987 1990 Fig. 5.20: Sales of leaded and unleaded gasoline in Canada (compiled from Lafleur 1994) gasoline combustion on the immediate environment. Moss samples collected in the Fraser Valley in the period of 1960 - 66 followed the general trend and were found to have extremely high lead levels corresponding to atmospheric lead originating from automotive exhaust. In 1980 unleaded gasoline comprised 35% of the total gasoline sales (Fig. 5.20). Mosses collected in the Fraser Valley between 1975 - 1980 showed a considerable decrease in lead levels, compared to those collected between 1960 - 1966 (Fig. 5.13). Reduction of atmospheric lead levels due to the increased use of unleaded gasoline, has also been confirmed by direct air measurements by the GVRD (Fig. 5.21). Al l reported sites showed a substantial decrease in lead levels, between 1975 and 1980. After the phase-out of leaded gasoline was completed in December 1990 (Lafleur 1994), lead levels dropped below detection limit for air direct air sampling (Fig. 5.21) (see also Chapter 6). Samples of Isothecium. stoloniferum collected in 1993 reflected this trend. 118 -•—Downtown Vancouver (1) • « 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 Fig. 5.21: Suspended particulate lead in the ambient air of the Greater Vancouver Regional District. Measured by direct air measurements (compiled from GVRD 1976, 1978, 1981, 1984, 1987, 1991). They showed the lowest lead concentration of all samples investigated (Fig. 5.13). Lead accumulation in moss tissue today either originates from local industrial sources, waste incineration, aviation fuel or U.S. bought gasoline. The decreasing lead concentration in moss tissue was contrasted by the increase in manganese that was found in the same moss samples from the Fraser Valley (Fig. 5.13). Between 1960 - 66 and 1993 the manganese concentration in moss tissue increased significantly (Fig. 5.14). This increase was seen predominantly at sites exposed to the air stream from the western, urban area with high traffic volume. Raised manganese levels in the ambient air, as well as in near highway soils, have been reported as a response to the introduction of MMT as an antiknock additive in the 1970's (Loranger et al. 1994, Cooper 1984, Joselow et al. 1978). No direct 119 Fraser Sw Sweden Germany Bavaria Chromium Fraser Sw Sweden Bavaria Fig. 5 . 2 2 : Comparison to literature data: Changes of metal concentration ( P b , Cd, Cr) in moss tissue since the 1960's in the Fraser Valley, Sweden, Germany, and Bavaria. In the present study 60 refers to the 1960 - 66 collection, 70 refers to the 1975 - 80 collection. All other years indicate actual collection dates. Species used are: Fraser Valley: Isothecium stoloniferum. Sweden Pleurozium schreberi and Hylocomium splendens, Germany 1976: Hypnum cupressiforme, Germany 1991: mostly Pleurozium schreberi, Bavaria 1978: Hypnum cupressiforme, Bavaria 1991: mostly Pleurozium schreberi (compiled from: Ruehling et al. 1987, Herpin 1994, Herrman 1976, Thomas 1981). 121 correlation of manganese content in Isothecium. stoloniferum to traffic volume was found for the regional 1993 Fraser Valley survey (see Section 4.4.4 and Appendix D, Tab. D5). The general increase overtime, however, was prominent. The general effect for the whole survey area might be attributed to the increased use of MMT in gasoline. Manganese levels in the ambient air of the Fraser Valley are in general low and for most sites at the suggested natural background level of 0.01-0.04 ug/m3 (GVRD 1994). However, an increasing trend persists (Fig. 5.13). Levels as experienced today in major metropolitan areas, ranging from 0.017 to 0.199 ug/m3 in several Ontario cities, are well below the WHO standard of 1 ug/m3 (Lynam et al. 1994). Nevertheless, MMT has been banned for health reason in the U.S. Canada is deliberating the banning of MMT as well, but mainly as a response to the car manufacturers who claim that MMT is harmful to vehicle engines (Westell 1995). 5.5 Literature Comparison The general decrease of heavy metals in moss samples from the Fraser Valley was similar to the declining trend of atmospheric metals reported from moss analysis studies for Sweden, Germany, Bavaria/Germany (Fig. 5.22) and Poland (Grodzinska et al. 1990). Particulate emissions in the ambient air, as measured by direct air sampling, has been decreasing since the 1970's not only in the Fraser Valley (Fig. 6.2), but also in Sweden, Germany and Poland. Metal concentration in moss samples collected over time from the same areas reflected the reduced particulate loadings in the ambient air (Grodzinska et al. 1990, Ruehling & Tyler 1984). Reduction of heavy metal processing industry and 120 Fig. 5.22a: Comparison to literature data: Changes of metal concentration (Ni, Zn) in moss tissue since the 1960's in the Fraser Valley, Sweden, Germany, and Bavaria. In the present study 60 refers to the 1960 - 66 collection, 70 refers to the 1975 - 80 collection. A l l other years indicate actual collection dates. Species used are: Fraser Valley: Isothecium stoloniferum. Sweden Pleurozium schreberi and Hylocomium splendens, Germany 1976: Hypnum cupressiforme, Germany 1991: mostly Pleurozium schreberi, Bavaria 1978: Hypnum cupressiforme, Bavaria 1991: mostly Pleurozium schreberi (compiled from: Ruehling et al. 1987, Herpin 1994, Herrman 1976, Thomas 1981) 121a implementation of emission control technology to comply with stringent air quality regulations, have been regarded as the principal factors reducing atmospheric metal levels (Ruehling et al. 1987, Grodzinska et al. 1990). A decrease of lead in moss samples was evident in all countries and could be related to lowered lead levels in gasoline since the 1970's. In Sweden, for instance, lead added to gasoline in 1973 amounted to 0.35 g/1. In 1986 it was reduced to 0.01 g/1. Lead concentration in moss samples has dropped correspondingly: Southwestern Sweden reported an average lead concenttation of 74 ppm in moss samples collected in 1968, prior to the lead reduction initiative and only 26 ppm for moss samples collected in 1986 (Ruehling et al. 1987). It can be expected that those levels have dropped even further in recent years. In Germany the effect was even more pronounced. The reduction of lead levels in gasoline has caused lead levels in the ambient air to drop from 1.1 ug/m3 in 1974 to 0.1 ug/m3 in 1990 (Pfeffer 1994). Lead concentration in mosses collected in Germany dropped from 90.6 ppm to 15.4 ppm (Herrmann 1976, Herpin 1994). Unfortunately no reliable data regarding the use of manganese in gasoline and its reflection in moss tissue were available. Cadmium, nickel and zinc, all related to coal, wood or oil combustion (Pacyna 1986a), showed the most striking decline in Germany. Municipal power generation in the 1960's relied almost exclusively on coal combustion. Additional emissions originated from individual wood/coal stoves for space heating. A market driven economy led to extensive coal extraction in several areas of Germany during the 1960's and 1970's. Central oil heating was gradually gaining importance during the 1970's, replacing the coal and wood stoves. Together coal extraction, coal combustion for power generation 122 and spaceheating, and wood and oil combustion accounted for high levels of cadmium, nickel and zinc in moss samples from 1976 (Herrmann 1976). During that time additional metals were emitted from industrial activity, such as steel fabrication and metal manufacturing. In the 1980's a general switch from coal based power generation to nuclear power plants took place. Most coal mines ceased operation in the 1980's. This, along with the replacement of coal and oil furnaces for spaceheating through electricity based systems, and industrial changes accounted for a substantial reduction of metal levels in moss samples. Cadmium levels dropped from 2.02 ppm in 1976 to 0.35 in 1991. Nickel dropped from 15 to 2.8 ppm and zinc from 242 to 60.6 ppm (Herrmann 1976, Herpin 1994). Some of this reduction might be a result of interspecies variation. The 1991 survey was based mostly on samples of Pleurozium schreberi, which is said to accumulate metals at a lower rate than Hypnum cupressiforme, which was used in the 1976 survey (Folkeson 1979). But even at the highest estimate of interspecies variation this alone cannot account for the difference (see Section 1.2.4.4). Difference in metal concentration in mosses from the 1970's and the 1990's was not quite as pronounced in Bavaria, a southern German state. The earlier study used Hypnum. cupressiforme and the latter Pleurozium. schreberi. As differences were not as pronounced as in the survey of Germany, it is unlikely that changes observed overtime were caused entirely by interspecies variation. Industrial processes are far more likely to be predominantly responsible for the changes in moss metal concentration. No open pit coal mines were operating in -Bavaria and heavy industrial activity was and still is scarce. Hence, atmospheric metal loadings have not undergone significant changes in this part of Germany. The effect of coal combustion on metal concentration in moss samples could 123 also be evaluated when metal concentration in mosses from different German states were compared. Coal stoves are still being used today to some extent in Berlin and former East Germany. Moss samples collected in those areas do record higher cadmium, nickel and zinc loadings for 1991, than those from states in former West Germany (Herpin 1994). 5.6 Conclusion A significant decline of atmospheric lead, cadmium, chromium, nickel and zinc was inferred from the analysis of moss tissue from the Fraser Valley since the 1960's. Manganese concentration, in contrast, increased substantially. Similar trends have been reported from European 'moss method' studies (Ruehling et. al. 1987). Changes of atmospheric metal levels over time were clearly related to changes in anthropogenic activities. The changes in industrial activity, implementation of pollution control devices, the switch from oil to gas and electricity for space heating purposes, the abandonment of lead and the addition of manganese to gasoline, represent only a few of those changes. The effects of these changes were seen as a decrease of atmospheric metal pollution in general and a contrasting increase of atmospheric manganese. 124 CHAPTER 6: 'THE VALUE OF THE 'MOSS METHOD' COMPARISON OF THE MOSS METHOD TO DIRECT AIR MEASUREMENTS AND ITS USE AS GENERAL AIR QUALITY INDICATOR 6.1 The 'Moss Method' compared to Direct Metal Measurements The GVRD Air Quality & Source Control Department maintains an ambient air monitoring program for the western region of the study area. Particulate matter is analyzed at 24 stations for lead and at 12 stations for cadmium, chromium, nickel, zinc, manganese, and copper. Al l stations are located within the GVRD area. Measurements are taken with a high-volume-air sampler, which draws a certain air volume through a filter. The filter is then analyzed for the various elements. The sampler is operated once weekly for a 24 h period (GVRD 1993c). Atmospheric metal levels in the GVRD are generally low. As metals are allowed to accumulate on the filter for only a short period of time, differences between measuring stations cannot be observed with this direct air sampling method. In the 'moss method', employed in the present study, atmospheric metals are allowed to accumulate in the moss tissue for a period of 2 - 3 years. Therefore, differences between the different measuring stations within the GVRD become apparent. Table 6.1 provides an overview of the concentration ranges covered by both methods. 125 T A B L E 6.1: Concentration ranges detected in air and moss samples from the GVRD. (air = technical data from GVRD (1993), moss = data from present study) Metal Air (ug/m3) Moss (ppm/d.w.) Pb <0.02 - 0.05 3.9 - 47.5 Cd all B.D.L. 0.10 - 0.97 Cr all B.D.L. 0.3 - 2.2 Ni all B.D.L. 0,6 - 4.3 Zn 0.01 - 0.06 27.2 - 99.0 Mn <0.01 - 0.06 39 - 409 Increased sensitivity at lower metal levels is also advantageous in the historical analysis of metal levels. The moss method, as used in the present study, reported significant changes for all metals since the 1960's. A general decrease for lead, cadmium, chromium, nickel, and zinc and an increase for manganese were found when herbarium moss samples from different time periods were analyzed (see Fig. 5.13). Direct measurements of metals in the ambient air have been recorded by the Air Quality and Source Control Department since 1975 for most metals. Table 6.2 lists the direct measurements, obtained at Coquitlam Municipal Hall, one of the measuring stations, where lead reduction was most prominent (Fig. 5.21). Only lead and zinc levels in the ambient air showed a decrease comparable to that observed by the moss method. For all other metals the direct air measurements were not able to detect any significant changes over time, which is in contrast to the findings of the moss method. The moss method is therefore considered more suitable if differences between different sites or changes over time are investigated. The method is most valuable in areas of low atmospheric metal 126 levels, because accumulation allows for increased sensitivity. Technical (direct) air measurements are advantageous when direct exposure to atmospheric metals has to be considered in relation to immediate public health concerns. Table 6.2: Atmospheric metal levels at Coquitlam Municipal Hall. 1975 - 1990 (values in ug/m3, compiled from GVRD 1978, 1981, 1984, 1987, 1991) Year Pb Cd Cr Ni Zn M n 1975 3.67 B.D.L . B.D.L B.D.L 0.26 0.1 1980 1.10 B.D.L B.D.L B.D.L 0.09 <0.05 1985 1.00 B.D.L B.D.L B.D.L 0.05 0.05 1990 0.08 B.D.L B.D.L B.D.L 0.05 0.06 6.2 The 'Moss Method' as a General Particulate Pollution Indicator Heavy metals are usually emitted as one component of particulate matter. Therefore, the hypothesis was proposed that metal values obtained with the 'moss method' could be used as an indicator for the general particulate pollution pattern. The GVRD Air Quality & Source Control Department measures general particulates at 39 monitoring stations throughout the GVRD area. Figure 6.1 shows the annual averages for particulate measurements in 1993. The particulate distribution pattern was, in only a few areas, similar to the metal data 'obtained' by the moss method. Measurements at T18 and T20 in South Burnaby and at station 15 and 33 in Richmond were high, similar to the findings of the 'moss method' (see Fig. 4.1 - 4.6). Direct measurements in the North Shore mountains (30, 29, 31, T15) and in the North Bumaby/Port Moody area (T5, T20, / 127 T14, 22, T 10, T7) showed comparably low particulate levels. This is in contrast the metal data obtained by the 'moss method', which reports maximum metal concentration in mosses from these sites. A Spearman rank correlation showed significant relationships only between general particulates and zinc and chromium (p<0.05). All statistical results are reported in Appendix C (C5). It might be speculated that this reflects particulate emissions related to traffic. Zinc, from tire abrasion, and possibly also chromium, from stainless steel abrasion or catalyst exhaust, are likely to be abundant in general traffic derived particulate matter. High particulate readings at the airport (Fig. 6.1) where tire Fig. 6.1: Direct air measurements of particulate matter the Fraser Valley. The data is recorded in Appendix CI Table CI. (compiled from: GVRD 1994) 128 abrasion from airplane traffic is common, is reflected in high zinc concentrations in mosses collected at Macdonald Beach (4b) close to the airport. To estimate total particulate emission in relation to traffic and the consequent metal accumulation in mosses a separate study, isolating traffic effects is necessary. The lack of correlation to any other metal is related to the fact that most particulate emissions are not likely to have a high metal content. Two thirds of all particulate emissions originate from point sources and two thirds of those point sources are related to bulk shipping terminals and wood processing (GVRD 1993b). Both involve processes that generate high amounts of particulates, but relatively little heavy metals. This accounts for the high particulate readings in the Vancouver Harbour area (Tl-A, 1), where the moss method did not indicate extremely high values (Fig. 4.1 - 4.6). Petroleum refining, in contrast, is responsible for only 3% of the total particulate emissions in the GVRD, but those particulates are expected to have a high metal content. Consequently, GVRD monitoring stations in the North Burnaby/Port Moody area, where most refineries are located, report low overall particulate emissions. In this area the moss method is more sensitive with respect to particulate emissions with high metal content. The historic moss analysis, however, did show some similarity to the GVRD direct measurements. The general particulate decline since the early 1970's (Fig. 6.2) was similar to the declining trend of metal concentrations in moss samples from different time periods. The decline in general particulates is a positive indicator for an overall improvement in pollution prevention and reduction. These measures affected metal emitting point sources, such as metal foundries, metal fabricating and petroleum refining operations, cement plants and chemical manufacturing, to the same extent as non-metal 129 particulate emission sources. Therefore a decline of particulate emission was seen in both, the general particulate emission sources and the metal containing particulate sources. In conclusion, the 'moss method' should not be used to estimate general particulate pollution. Although some correlations exist, they might be related to specific local features. The bulk of particulate pollution is derived from non-metal emitting sources and this is not reflected in data obtained by the moss method. Fig. 6.2: Particulates in the ambient air. 1973 - 1993. Direct air measurements of the. GVRD (values in ug/m3), (compiled from: GVRD 1976,1978, 1981, 1984, 1987, 1991, 1994). 130 6.3 The 'Moss Method' as General Air Quality Indicator The 'moss method' described the pollution pattern for atmospheric heavy metal metals. It was tested if this metal pollution pattern could be used as a general air quality indicator. Relation of the moss method data to an existing air quality index and other primary air pollutants such as SOz and NOx was investigated. The GVRD issues an hourly general air quality index (AQI) for 10 stations throughout the Fraser Valley. The index values are obtained from a pollutant combination. Arbitrary numbers from 0-25 indicate "good" air quality, from 25 -50 "fair" air quality, and from 50 - 100 "poor" air quality (GVRD 1994). Poor air quality in 1993 was only reported for 2 hours in Langley (T27). At all other stations some hours of fair air quality were reported for 1993, but 0 10 20 Km Fig. 6 .3: Air quality index readings in the Fraser Valley. The number of hours reporting a fair airquality index is indicated (Appendix C, Tab. C2). 131 the index showed generally good air quality. Figure 6.3 shows the numbers of hours in 1993, when a fair AQI was reported. The metal values obtained by the moss method (see Fig. 4.7) did not reflect the observed pattern. The air quality index showed high values in Richmond (T17) and Port Moody (T9), which was similar to the findings of the moss method. However, AQI values comparable to those from the western regions were also reported for regions outside the GVRD, such as Langley (T27) and Abbotsford (T28). This was in contrast to the metal distribution pattern observed with the moss method, which indicated low readings for most stations outside the GVRD area. A Spearman rank correlation test was unable to detect any significant relationship, between the AQI and the metal data obtained by the moss method. Statistical results are given in Appendix C, Tab. C5. The GVRD also maintains NO x and S0 2 monitoring programs for the Fraser Valley. The annual means for 1993 are displayed in Figure 6.4 and Fig. 6.5. The general distribution pattern for both pollutants differed from the metal distribution obtained by the moss method. NOxand S0 2 are high in the Downtown Vancouver area, but low in the North Bumaby/Port Moody area and in the North Shore Mountains. Both of the latter sites featured extremely high values of metal concentrations in moss samples. A Spearman rank con-elation test revealed no significant relationship between S0 2 and the metal data. For NO x , significant correlation was found to chromium and zinc levels in the moss samples (Spearman rank correlation test, p<0.05), but not for any other metal. Statistical results are given in Appendix C (Tab. C5). NO x emissions in the Fraser Valley originate to 77% from mobile sources such as automobiles, truck, vessels and aircraft (GVRD 1993b). The Spearman rank correlation indicated that areas with traffic related 132 0 10 20 Km Fig. 6.4: Direct Air Measurements of NO x in the Fraser Valley. The data is recorded in Appendix CI Table C2. (compiled from GVRD 1994) Fig. 6.5: Direct Air Measurements of S0 2 in the Fraser Valley. The data is recorded in Appendix CI Table C2. (compiled from GVRD 1994) 133 NOx emissions showed high levels of zinc and chromium in the moss tissue. This supported the hypothesis that zinc and chromium measured by the moss method might originated largely from traffic (see also Section 6.2). Aside from the small potential to employ 'moss method' zinc and chromium measurements as indicators for emissions from mobile sources, the use of 'moss method' data as indicator for general air quality is not feasible. 6.4 Conclusion r The 'moss method' is a suitable tool for assessing atmospheric metal pollution at low levels. When technical instruments, analyzing the air directly, cannot differentiate between different pollutant regimes of an area, the moss method can be used as an alternative or additional tool. Accumulation of metals over a long period of time allows for increased sensitivity. However, the moss method should not be used as a general indicator, neither for particulate nor for other air pollution parametersThe moss method data for zinc and chromium was found to correlate to direct measurements of particulates and NO x . This might indicate a remote potential for the use of moss data as a detection device for traffic related pollution. However, at the present time, it cannot be considered a viable concept. It is therefore recommended to use the 'moss method' exclusively for the assessment of atmospheric heavy metal pollution. 134 General Conclusion Atmospheric heavy metals in the Fraser Valley showed a distinct accumulation in the western area, the GVRD. Metal concentrations in samples of Isothecium stoloniferum were comparable to concentrations reported from similar 'moss method' surveys in Europe. The pollution level could be attributed to a high population density, traffic and industrial activity. Some pollution transport from the valley bottom north west into the Coast Mountain range might be related to local air movement. High levels were also related to high precipitation suggesting an increased amount of metals being deposited as wet deposition. In contrast to the high metal levels in the GVRD, mosses from the eastern valley featured rather low metal concentrations, in many cases comparable to natural background levels reported from 'moss method' studies in remote areas. Therefore, eastward directed long-range metal transport from the urbanized western area to the eastern agricultural areas could not be suggested. The regional differences between metal levels was also apparent from the 1960's metal distribution pattern. Metal concentration overall, however, has decreased significantly over the past 30 years. Reduction of atmospheric metal levels might be attributed to a reduction of heavy industries in the Fraser Valley, the implementation of efficient pollution control equipment, abandonment of leaded gasoline and changes in fossil fuel combustion. In contrast to the general decline in metal levels an increase was found for manganese levels. 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Water, Air, and Soil Pollution, 21, 261-270. 151 APPENDICES Appendix A: Fraser Valley Collection Data Appendix B: Herbarium Collection Data Appendix C: Direct Measurement Data Appendix D: The GVRD Gridded Emission Model APPENDIX A: FRASER VALLEY DATA A l : Sample Site Data Table A l : Sample Sites, Districts, and Metal Concentration Site# Site name Lat. Long. Area Pb Cd Cr Ni Zn Mn l Bowen Island 492330 1232100 G V R D 6.7 0.18 0.4 0.8 31.0 104 2 Cypress 492100 1231200 G V R D 47.5 0.35 0.7 2.1 52.7 97 3a Stanley Pk 491800 1230900 G V R D 23.4 0.40 1.3 2.4 40.0 200 3b Lighthouse Pk. 492000 1231600 G V R D 33.8 0.28 0.6 2.7 54.2 409 4a U E L 491515 1231300 G V R D 6.7 0.22 0.8 1.5 39.6 225 4b MacDonald Beach 491245 1231000 G V R D 10.6 0.72 1.5 3.1 84.8 74 8a Capilano 492100 1230645 G V R D 42.7 0.46 0.8 2.5 59.8 191 8b Lynn Canyon 492015 1230100 G V R D 36.8 0.54 1.1 2.7 58.3 328 9 Trout Lake 491515 1230330 G V R D 10.1 0.68 2.0 2.3 60.7 39 10 Richmond Nat. Pk 491030 1230500 G V R D 13.5 0.38 1.6 1.8 78.3 387 11a Ladner Harbour Pk 490530 1230515 G V R D 7.5 0.49 1.6 2.1 56.3 76 l i b Point Roberts 490015 1230300 G V R D 3.9 0.15 0.5 0.6 27.2 151 12 Seymour dam 492530 1225830 G V R D 18.5 0.42 0.5 2.0 40.9 347 13a Capitol Hi l l 491715 1225945 G V R D 21.2 0.29 0.8 2.3 46.4 123 13b Rocky Pt. Pk. 491645 1225015 G V R D 20.7 0.26 2.1 2.7 85.3 80 13c Seymour Pk. Headqt. 491930 1225815 G V R D 12.6 0.29 0.5 1.6 42.8 130 13d Belcarra 491815 1225545 G V R D 23.4 0.33 1.1 2.4 46.4 86 14a Burnaby Lake 491445 1225730 G V R D 42.4 0.31 1.6 2.0 92.9 324 14b Fraser River Pk. 491145 1230000 G V R D 23.6 0.97 2.2 4.3 99.0 84 15 Delta 490945 1225500 G V R D 8.1 0.30 1.0 1.7 41.4 87 17 Coquitlam Lk 492300 1224645 G V R D 23.2 0.59 0.5 1.6 48.1 314 18 Coquitlam City 491745 1225015 G V R D 11.6 0.33 0.7 1.5 40.7 146 19 Mundy Pk 491530 1224945 G V R D 17.6 0.33 0.8 2.0 56.0 219 20 Tynehead Pk 491100 1224600 G V R D 9.3 0.28 0.8 1.5 40.0 236 21 Crescent Pk 490300 1225145 G V R D 7.2 0.16 0.6 1.4 32.2 142 22 Burke Mtn 491845 1224430 G V R D 19.7 0.35 0.6 1.8 . 45.2 100 23 Derby Reach 491230 1223630 East Valley 8.2 0.32 1.4 2.1 33.1 91 24 Langley City 490545 1223930 East Valley 8.5 0.13 1.1 2.5 29.3 130 25 Campbell Pk. 490115 1223900 East Valley 4.1 0.17 0.6 1.1 23.2 79 26 U B C Research For. 491615 1223330 East Valley 13.2 0.35 0.4 1.1 32.4 164 27 Kananaka 491145 1223200 East Valley 5.3 0.20 1.3 1.3 27.4 122 28 Glen Valley 490800 1222815 East Valley 3.5 0.18 0.5 1.0 33.5 129 30 Golden Ears 492015 1222730 East Valley 6.5 0.36 0.4 1.1 30.2 163 31 Rolley Lake 491430 1222300 East Valley 8.5 0.36 0.3 0.9 30.6 318. 33 Aldergrove Lk 490045 1222745 East Valley 2.1 0.16 0.6 0.90 27.7 399 34 Sylvester Road 491730 1221345 East Valley 16.1 0.41 1.2 1.6 33.8 113 35 Hatzic Lake 490930 1221445 East Valley 3.9 0.19 1.0 1.0 24.8 96 36 Matsqui Trail 490730 1221230 East Valley 3.2 0.18 1.3 1.3 31.5 143 37 Mills Lk, Clearbrook 490245 1221900 East Valley . 9.2 0.21 1.1 1.7 36.7 146 39 Deroche 491115 1220430 East Valley 3.8 0.26 1.5 0.9 26.8 62 40 Sumas Mtn. 490615 1221000 East Valley 4.0 0.20 0.9 1.1 25.6 178 42 Statlu Creek 492045 1220215 East Valley 6.0 0.24 0.9 0.8 26.8 398 153 Site# Site name Lat. Long. Area Pb Cd Cr Ni Zn M n 44 Chilliwack Mtn 490915 1220115 East Valley 4.2 0.21 1.2 l . i 23.8 88 45 Vedder Peak 490430 1220230 East Valley 4.7 0.16 0.9 0.9 36.0 76 46 Harrison West 492430 1215030 East Valley 3.3 0.13 1.2 1.1 25.6 147 47 Weaver Lake 491930 1215230 East Valley 1.8 0.33 0.3 0.6 29.3 167 48 Mt. Wood 491400 1215145 East Valley 4.3 0.16 0.6 0.9 27.9 58 49 Nixon Road 490915 1214800 East Valley 5.2 0.24 0.7 1.0 27.9 61 50 Tamahi 490415 1215000 East Valley 5.7 0.14 3.3 2.8 23.9 101 51 Sasquatch/Harrison 492115 1214330 East Valley 2.8 0.29 0.9 1.4 28.2 245 53 Bridal Vei l Falls 491115 1214430 East Valley 2.9 0.20 0.8 1.0 22.5 31 54 Foley Creek 490600 1213815 East Valley 7.0 0.24 0.9 1.0 38.0 . 824 55 Ruby Creek 492230 1213700 East Valley 4.4 0.17 0.8 1.3 48.2 143 56 Hunter Creek 492100 1213430 East Valley 3.7 0.17 0.8 1.1 24.7 84 57 Jones Lake 491445 1213600 East Valley 3.5 0.21 1.1 0.9 39.4 702 58a Kawakwa Lake 492300 1212345 East Valley 4.6 0.14 0.9 0.9 22.5 56 58b Waterfall 492715 1212630 East Valley 2.8 0.17 0.8 1.1 22.5 95 59 Silver Lake 492030 1212815 East Valley 3.5 0.13 3.2 0.9 22.1 139 HoweC Shannon Falls 494015 1230915 no category 4.7 0.12 0.7 0.7 29.3 179 Howe B Deeks Lake 493230 1231411 G V R D 5.5 0.11 0.5 1.0 23.9 171 Howe A Lions Bay 492715 1231330 G V R D 9.1 0.10 0.3 0.9 27.5 150 Spec. Galiano 490030 1233430 no category 3.2 0.10 1.5 1.0 28.1 104 154 A2: Frequency Distribution Diagrams and Category Limits 12 -i , , — . " 11 + ppm lead Fig. Al: Frequency distribution for lead. Vertical lines represent to the category limits used in geographical representation of results (Chapter 4). 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 ppm cadmium Fig. A2: Frequency distribution for cadmium. Vertical lines represent to the.category limits used in geographical representation of results (Chapter 4). 155 w C L E co w H— O 14 13 12 + 11 10 9 8 7 6 5 4 3 2 1 0 Mi 0 0.2 0.4 0.6 0.8 1 i i i i Chromium I i I r i r i 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 ppm chromium Fig. A3: Frequency distribution for chromium. Vertical lines represent to the category limits used in geographical representation of results (Chapter 4). 15 14 13 12 11 + 10 8 + 111, CL E co co 7 2 6 5 4 3 2 1 0 l a l B l B l l H l H l I W I l B l f l I I I I I I I I l Fi 0.50 0.80 1.10 1.40 1.70 2.00 2.30 2.60 2.90 3.20 3.50 3.80 4.10 4.40 ppm nickel Fig. A4: Frequency distribution for nickel. Vertical lines represent to the category limits used in geographical representation of results (Chapter 4). Nickel 156 7 6 co ^ A E CO w o 3 2-1 o mmmm\ i m ffw1 w PI Zinc 23 28 33 38 43 48 53 58 63 68 73 78 83 88 93 98 ppm Zn Fig. A5: Frequency distribution for zinc. Vertical lines represent to the category limits used in geographical representation of results (Chapter 4 ) . CO E CD CO o 3 2 + r 1 + 0 I f\ WrMrV "WWl u M a n g a n e s e 30 80 130 180 230 280 330 380 430 480 530 580 630 680 730 780 830 ppm Mn Fig. A6: Frequency distribution for manganese. Vertical lines represent to the category limits used in geographical representation of results (Chapter 4). 157 A3: Sample Site Parameters Tab. A 2 : Natural and anthropogenic parameters for the Fraser Valley sample sites. Data is compiled or generated as outlined in Chapter 2. Precip (total) = precipitation data from Staeger & Wallis (1968).Precipitation amount is replaced with arbitrary numbers to fit spearman rank correlation requirements (1= <40 inch, 2=40-50, 3=50-60, 4=60-70, 5=70-80, 6=>80). Precip (GVRD) = precipitation data (in mm) from Oke & Hay 1994. Site# Site name Metal Index Precip (total) Precip (GVRD) Elevation (m) Population 1 Bowen Island 7 30 1500 2 Cypress 16 6 2000 400 32680 3a Stanley Pk 15 4 1500 20 143775 3b Lighthouse Pk. 15 4 1200 60 9225 4a UEL 10 3 1300 80 80820 4b MacDonald Beach 15 2 1000 0 98515 8a Capilano 16 6 2000 100 85745 8b Lynn Canyon 16 6 2000 100 78270 9 Trout Lake 15 3 1500 30 305115 10 Richmond Nature Pk 14 2 1100 0 83525 11a Ladner Harbour Pk 15 1 0 18105 l i b Point Roberts 4 1 15 19505 12 Seymour dam 14 6 3000 200 0 13a Capitol Hill 14 5 1800 20 131700 13b Rocky Pt. Pk. 15 5 0 103560 13c Seymour Pk. Headqt. < 12 5 2000 120 38800 13d Belcarra 15 5 1500 0 43690 14a Burnaby Lake 14 4 1200 15 167100 14b Fraser River Pk. 16 2 1300 0 94490 15 Delta 12 3 30 102535 17 Coquitlam Lk 15 6 160 0 18 Coquitlam City 12 5 0 66565 19 Mundy Pk 14 5 160 115830 20 Tynehead Pk 12 4 15 62190 21 Crescent Pk 9 2 60 30235 22 Burke Mtn 13 6 400 24870 23 Derby Reach 12 4 0 50285 24 Langley City 10 3 0 46490 25 Campbell Pk. 6 3 60 6250 26 UBC Research For. 11 6 200 3975 27 Kananaka 7 4 75 16050 28 Glen Valley 8 3 20 2170 30 Golden Ears 10 6 200 535 158 Site# Site name Metal Index Precip (total) Precip (GVRD) Elevation (m) Population 31 Rolley Lake 10 6 220 730 33 Aldergrove Lk 5 3 50 6245 34 Sylvester Road 14 6 160 725 35 Hatzic Lake 6 5 20 13985 36 Matsqui Trail 7 4 0 3890 37 Mills Lk, Clearbrook 11 3 60 66560 39 Deroche 6 5 0 900 40 Sumas Mtn. 6 5 500 460 42 Statlu Creek 6 6 160 0 44 Chilliwack Mtn 7 4 300 9670 45 Vedder Peak 7 4 80 4840 46 Harrison West 5 6 40 0 47 Weaver Lake 7 6 40 405 48 Mt. Wood 6 5 160 2595 49 Nixon Road 8 4 120 2375 50 Tamahi 8 4 160 965 51 S asq uatch/Harrison 9 6 120 125 53 Bridal Veil Falls 5 4 120 1740 54 Foley Creek 9 5 360 0 55 Ruby Creek 9 5 200 210 56 Hunter Creek 6 4 80 700 57 Jones Lake 7 5 660 0 58a Kawakwa Lake 5 4 60 4435 58b Waterfall 6 5 180 585 59 Silver Lake 4 5 180 1545 Howe C Shannon Falls 6 60 5245 Howe B Deeks Lake 5 210 0 Howe A Lions Bay 7 320 1475 Spec. Galiano 6 20 0 159 A 4 : Correlation Matrix Tab. A 3 : Spearman rank correlation for metal concentration. The values represent the correlation coefficient rs:* = significant at p<0.05, **= significant at p<0.01, ***= significant at p<0.00 (n=62). The tests were carried out individually: metals (n=62), precip total, population, elevation, and metals (n=58), precip gvrd and metals (n=15). Pb Cd Cr Ni Zn Mn Elevation Pb -0.114 Cd 0.651*** -0.064 Cr 0.052 0.100 -0.361* Ni 0.725*** 0.560*** 0.427*** -0.299* Zn 0771***. 0.710*** 0.169 0.674*** -0.255 Mn 0.158 0.118 -0.246 -0.059 0.182 0.248 Precip total 0.109 0.247 -0.283* -0.130 -0.039 0.303* 0.558*** Population 0.589*** 0.326* 0.314* 0.623*** 0.571*** 0.760*** -0.546*** Precip GVRD 0.261 0.037 -0.602* -0.201 -0.490 -0.002 160 A5: Precipitation Maps F i g . A 8 : Precipitation map for the Vancouver area (from Oke & Hay 1994) APPENDIX B: HERBARIUM RELATED DATA Tab. BI: Herbarium collection: Sample site, collection dates and metal concentration (in ppm/dry weight). University Endowment Lands, UBC Research Forest, and Bridal Veil Falls provide samples for both the timeline analysis and the 1960-66 and the 1975-1980 collection. Sample # Date Location Long. Lat. Pb Cd Zn M n Ni Cr I960 « 6 u tlktlion 1 64/05/27 Hope 12127 4923 99.3 0.27 31.7 119 9.1 4.3 2 . 64/06/05 Hope 12127 4923 86.2 0.39 32.8 115 4.3 1.9 3 64/06/05 Hope 12127 4923 42.9 0.28 34.2 140 2.7 0.8 4 62/05/02 Harrison 12148 4917 65.9 0.19 74.6 132 4.8 1.4 5 62/05/02 Harrison 12148 4917 4.4 0.28 66.3 53 1.0 0.5 6 62/04/29 Cheam 12141 4915 42.9 0.39 33.2 98 4.2 • 2.4 7 62/04/29 Cheam 12141 4915 87.0 0.23 28.1 93 5.6 2.2 8 66/02/27 Matsqui 12211 4908 64.8 0.32 78.6 136 2.5 1.1 9 65/09/10 Sumas river 12209 4905 13.4 0.13 15.1 89 2.5 2.9 10 62/04/15 Burnaby Mtn. 12255 4917 33.2 0.74 116.6 103 5.2 1.4 11 66/03/13 Crescent Beach 12252 4903 109.1 0.33 86.1 72 3.2 1.5 12 61/06/18 Lions Bay 12313 4927 53.4 0.21 30.3 54 1.6 0.5 13 61/04/05 Capilano/Dam 12307 4921 94.0 0.46 53.7 79 4.3 1.8 14 60/06/12 Capilano/Dam 12307 4921 45.7 0.84 31.7 25 2.1 0.9 15 63/05/15 Indian arm 12254 4928 117.3 0.61 54.8 66 5.5 0.5 16 61/02/06 Lynn Canyon 12301 4921 103.4 1.00 128.3 46 4.8 0.8 59 63/06/06 Bowen Isl. 12321 4924 43.3 0.42 61.3 59 2.7 1.1 60 62/07/01 Bowen Isl. 12321 4924 50.0 0.30 67:4 54 3.2 0.7 61 60/10/10 Bowen Isl. 12321 4924 106.3 0.83 102.0 90 4.7 1.1 1975 - SO collection 17 80/06/05 Lions Bay 12313 4927 24.2 0.25 12.3 44 1.2 0.6 19 75/06/13 Jones Creek 12137 4918 30.5 0.17 19.5 102 10.3 10.3 20 75/06/10 Lindemann Lk. 12128 4908 14.4 0.12 20.2 137 0.6 0.9 21 77/02/19 Sumas Mtn. Rd. 12211 4905 44.8 0.23 22.3 90 2.4 1.6 22 78/11/16 Slesse Cr. 12142 4904 16.9 0.14 13.0 88 1.0 1.8 23 80/06/24 Ford Mtn. 12142 4905 10.7 0.23 20.5 89 1.3 0.5 24 80/06/22 Chilliwack Lk. 12128 4905 18.1 0.10 16.2 354 1.5 0.9 Univtisitv 1 ;.tiriii\u'tm>!il l.iinii I'ollciliiiii 27 49/07/27 UEL 12315 4915 78.3 0.33 160.0 72 7.0 1.4 29 49/07/27 UEL 12315 4915 61.5 0.48 87.6 98 5.1 1.4 30 49/07/27 UEL 12315 4915 63.4 0.33 108.5 71 7.3 1.9 31 49/07/27 UEL 12315 4915 171.3 0.45 55.9 131 9.0 3.2 32 60/11/02 Musqueam Pk. 12311 4914 195.5 1.06 152.8 146 9.2 3.0 28 61/01/16 UEL 12315 4915 206.5 0.54 78.2 93 5.5 1.2 26 66/10/20 UEL 12315 4915 141.6 0.98 65.6 72 3.6 1.8 25 87/04/08 UEL 12315 4915 72.8 0.18 27.4 76 1.28 1.0 162 Sample # Date Location Long. Lat. Pb Cd Zn Mn Ni Cr l .BC Kcseiirrli Forest iollei-tion 44 59/09/01 UBC Research 12235 4918 70.6 0.71 67.0 153 3.7 0.6 42 62/04/20 UBC Research 12235 4918 72.0 0.82 72.1 241 5.1 1.3 43 62/04/20 Blaney gorge 12235 4916 86.3 0.47 50.1 126 4.3 0.7 41 68/04/07 Kananaka Cr. 12231 4913 83.9 0.67 33.2 50 3.5 1.0 38 78/02/12 Golden Ears 12228 4920 45.9 0.25 26.3 37 1.4 0.9 40 78/04/06 UBC Research 12235 4918 41.1 0.60 23.8 87 1.7 0.2 39 78/04/06 Alouette River 12233 4917 77.8 0.40 55.9 215 3.0 0.6 Bridal \ i-il t-tills collection 58 49/07/08 Cheam Lake 12145 4911 36.6 0.29 66.7 99 4.2 3.0 57 49/07/08 Cheam Lake 12145 4911 72.9 0.28 85.4 146 5.3 3.7 56 64/02/02 Bridal Veil Falls 12144 4911 25.6 0.27 27.0 92 3.2 1.8 55 69/04/15 Bridal Veil Falls 12144 4911 80.6 0.20 22.7 99 3.4 1.4 54 71/03/13 Bridal Veil Falls 12144 4911 36.4 0.15 15.5 26 1.3 0.9 53 71/03/13 Bridal Veil Falls 12144 4911 49.3 0.34 22.0 84 2.4 1.2 52 71 Bridal Veil Falls 12144 4911 70.6 0.25 45.4 58 3.0 1.3 51 72/03/02 Bridal Veil Falls 12144 4911 99.1 0.37 23.8 79' 2.4 0.8 50 78/03/05 Bridal Veil Falls 12144 4911 26.8 0.18 32.8 46 1.5 0.8 49 78/03/05 Bridal Veil Falls 12144 4911 61.4 0.33 20.2 43 2.1 1.4 48 80/05/21 Bridal Veil Falls 12144 4911 63.4 0.31 38.6 143 3.6 1.2 46 80/05/21 Bridal Veil Falls 12144 4911 21.8 0.23 24.1 77 4.0 1.4 47 80/06/04 Bridal Veil Falls 12144 4911 93.4 0.27 24.1 247 2.3 0.4 45 86/01/30 Bridal Veil Falls 12144 4911 4.1 0.14 23.8 48 2.8 1.7 163 Tab. B2: Mean metal concentration for the GVRD district samples and East Valley samples for the 1960 - 66 Herbarium collection. Averages, standard deviation (ppm/dry weight) and the probabilities for the Null Hypothesis 'GVRD and East Valley samples are not different' are given (Mann-Whitney-U Statistic). Sample # Location Area Pb Cd Zn Mn Ni Cr 10 Burnaby Mtn. G V R D 33.2 0.74 116.6 103 5.2 1.4 11 Crescent Beach G V R D 109.1 0.33 86.1 72 3.2 1.5 12 Lions Bay G V R D 53.4 0.21 30.3 54 1.6 0.5 13 Capilano/Dam G V R D 94.0 0.46 53.7 79 4.3 1.8 14 Capilano/Dam G V R D 45.7 0.84 • 31.7 25 2.1 0.9 15 Indian arm G V R D 117.3 0.61 54.8 66 5.5 0.5 16 Lynn Canyon G V R D 103.4 1.00 128.3 46 4.8 0.8 59 Bowen Isl. G V R D 43.3 0.42 61.3 59 2.7 1.1 60 Bo wen Isl. G V R D 50.0 0.30 67.4 54 3.2 0.7 61 Bowen Isl. G V R D 106.3 0.83 102.0 90 4.7 1.1 32 Musqueam Pk. G V R D 195.5 1.06 152.8 146 9.2 3.0 28 U E L G V R D 206.5 0.54 78.2 93 5.5 1.2 26 U E L G V R D 141.6 0.98 65.6 72 3.6 1.8 /Y\f-rii K i-<;\Ki> 100.0 O.M 7 'U 74 4.3 1.3 Standard IJmsilion C \ R I ) 5f.J f).2l> i<) 1.9 0.7 1 Hope East Valley 99.3 0.27 31.7 119 9.1 4.3 2 Hope East Valley 86.2 0.39 32.8 115 4.3 1.9 3 Hope East Valley 42.9 0.28 34.2 140 2.7 0.8 4 Harrison East Valley 65.9 0.19 74.6 132 4.8 1.4 5 Harrison East Valley 4.4 0.28 66.3 53 1.0 0.5 "6 Cheam East Valley 42.9 0.39 33.2 98 4.2 2.4 7 Cheam East Valley 87.0 0.23 28.1 93 5.6 2.2 8 Matsqui East Valley 64.8 0.32 78.6 136 2.5 1.1 9 Sumas river East Valley 13.4 0.13 15.1 89 2.5 2.9 42 U B C Research East Valley 72.0 0.82 72.1 241 5.1 1.3 43 Blaney Cr. gorge East Valley 86.3 047 50.1 126 4.3 0.7 56 Bridal Vei l Falls East Valley 25.6 0.27 27.0 92 3.2 1.8 Au>r:i!>e l iasl \a lk> 57.6 0.34 45.3 119 4.1 1.8 Standard Dela t ion Kast \a lk> •» 1 .-• 0.1N 21.9 1111111 2 A 1.1 Mann - Whitney- U, probabilties 0.030 0.005 0.028 0.007 0.586 0.221 164 Tab. B3: 1960 - 66 collection samples and matched samples from the Fraser Valley 1993 collection. (* for manganese comparison the Cheam sites (6, 7) match with Jones Lake (57), one of the manganese outliers, was substituted with a Hunter Creek (56) match. Herbarium Herbarium 1960 - 66 Fraser 1993 Fraser 1993 Sample # Location Location Site# 59 Bowen Isl. Bowen Island 1 60 Bowen Isl. Bowen Island 1 61 Bowen Isl. Bowen Island 1 12 Lions Bay Lions Bay Howe A 13 Capilano/Dam Capilano 8a 14 Capilano/Dam . Capilano 8a 16 Lynn Canyon Lynn Canyon 8b 15 Indian arm Seymour dam 12 32 Musqueam Pk. Uel 4a 28 UEL Uel 4a 26 UEL Uel 4a 11 Crescent Beach Crescent Pk 21 10 Burnaby Mtn. Capitol hill 13a 42 UBC Research UBC research 26 43 Blaney Cr. gorge UBC research 26 8 Matsqui Matsqui trail 36 9 Sumas river Sumas mta. 40 6 Cheam Jones Lake* 57 7 Cheam Jones Lake* 57 56 Bridal Veil Falls BV Falls 53 4 Harrison Sasquatch/Harrison 51 5 larrison Sasquatch Harrison 51 1 Hope Kawakwa Lake 58a 2 lope Silver Lake 59 3 lope Waterfall 58b 165 Tab. B4: 1975 - 80 collection samples and matched samples from the Fraser Valley 1993 collection. (* for manganese comparison the Jones Creek Site (19) the match with Jones Lake (57) was substituted with a Hunter Creek (56) match. For Lindemann Lk (20), Slesse Cr. (22), and Chilliwack Lk. (24), the Foley Creek (54) match was substituted with a Tamahi (50) match. Both original matches, Jones Lake and Foley Creek showed outlier values for manganes. Herbarium Herbarium 1975 - 80 Fraser 1993 Fraser 1993 Sample # Location Location Site# 17 Lions Bay Lions Bay Howe A 21 Sumas Mtn. Rd. Sumas Mtn. 40 38 Golden Ears Golden Ears 30 40 UBC Research UBC Research 26 39 Alouette River Golden Ears 30 19 Jones Creek Jones Lake* 57 20 Lindemann Lk. Foley Creek* 54 22 Slesse Cr. Tamahi 50 23 Ford Mtn. Foley Creek* 54 24 Chilliwack Lk. Foley Creek* 54 50 Bridal Veil Falls Bridal Veil Falls 53 49 Bridal Veil Falls Bridal Veil Falls 53 48 Bridal Veil Falls Bridal Veil Falls 53 46 Bridal Veil Falls Bridal Veil Falls 53 47 Bridal Veil Falls Bridal Veil Falls 53 166 A P P E N D I X C : D I R E C T M E A S U R E M E N T D A T A ( C H A P T E R 3) Tab. CI: Particulate measurements at the GVRD air quality monitoring stations for 1993 (part) in ug/m3 and matched moss samples with metalindex from the Fraser Valley 1993 collection. GVRD GVRD GVRD GVRD GVRD Moss Moss Metal Stat.# Station name Lat. Long. Part Site Loction Index T l - A B.C.Hydro Hornby/Smythe 491654 1230724 39 3a Stanley 15 T2 Kits, 2550 W 10th Ave 491545 1230945 29 4a Uel 10 T3 Marpole, 250 W 70th Ave 491235 1230650 42 4b Macdonald 15 T4 Kensington Pk, 6400 E. Hastings 491645 1225811 22 13a Capitol 14 T5 Confederation Pk. 491700 1225952 25 13a Capitol 14 T7 Anmore 491840 1225130 15 18 Coquitiam City 12 T9 Rocky Point Park 491651 1225053 27 13b Rocky Pt.Pk 15 T10 Port Coquitlam, 475 Guilford way 491705 1224926 24 18 Coquitlam City 12 T13 North Delta, 8544 116thSt 490930 1225403 31 15 Delta 12 T14 Burnaby Mtn. 491645 1225442 17 13d Belcarra 15 T15 Surrey east, 19000 72nd Ave 490758 1224136 27 24 Langley City 10 T17 Richmond south 490831 1230628 30 10 Richmond Nature Pk 14 T18 Burnaby South 5455 Rumble St 491256 1225857 38 14b Fraser River Pk 16 T19 Richmond east, 16400 Cambie Rd 491105 1230228 40 10 Richmond nature Pk 14 T20 Burnaby East, 19th SflOth Ave 491220 1225707 60 14a Burnaby Lk. 14 T25 Seymour Falls/Seymour Dam 492614 1225754 13 12 Seymour dam 14 T27 Langley Central, 23752 52nd Ave 490546 1223359 24 24 Langley City 10 1 Centennial Pier, Vane. 491720 1230520 40 3a Stanley Pk. 15 2 C.N.R. Station 491628 1230547 29 3a Stanley Park 15 4 South Cambie, 425 Ontario 491452 1230615 26 9 Trout Lk. 15 9 B.C.I .T. , Burnaby 491455 1230005 29 14a Burnaby Lk . 14 12 Edmonds 491219 1225629 28 14a Burnaby Lk . 14 13 Sapperton, New Westminster 491316 1225355 41 14a Burnaby Lk . 14 15 Sea island, Airport, Main Terminal 491139 1231047 41 4b Macdonald 15 16 Richmond Municipal Hall 490949 1230811 31 10 Richmond Nature Pk. 14 18 Newton, Surrey 490903 1225106 27 21 Crescent Pk. 9 20 White Rock 490127 1224742 23 21 Crescent Pk. 9 22 College Park 491656 1225240 21 13b Rocky PLPk 15 23 Ladner 490515 1230454 22 11a Ladner Habour Park 15 24 English Bluff, 402 48th St Delta 490036 1230521 19 l i b Pt. Roberts 4 25 Tsawwassen ferry 490015 1230736 23 l i b Pt. Roberts 4 29 Central Lonsdale, North Van 491913 1230407 27 8a Capilano 16 30 Hollyburn 491954 1230922 21 2 . Cypress 16 31 Sherwood Park 491856 1225748 20 13c Seymour Pk head qt. 12 32 Coquitlam Munic.Hall 491420 1225139 47 19 Mundy Pk. 14 33 Mitchell Sch., Richmond 491107 1230739 48 10 Richmond Nature Pk. 14 37 Sunbury 490908 1225728 52 15 Delta 12 38 Knight 490507 1230404 29 9 Trout Lake 15 41 Port Coquitlam 491537 1224530 31 18 Coquitlam City 12 42 Annacis Island, Sewage treatment 490952 1225548 48 15 Delta 12 167 Tab. C2: Air quality index data and matched moss samples from the Fraser Valley 1993 collection. AQI = number of hours in 1993, when a fair air quality index was recorded (GVRD 1994)(*= Rocky Pt. Park (T9) is actually an average of three stations (T9/T10/T2). GVRD GVRD GVRD GVRD GVRD Moss Moss Metal Stat.# Station name AQI Lat, Long. Site# Location Index TI Downtown Vancouver 65 491658 1230714 3a Stanley Park 15 T4 North Burnaby 54 491645 1225811 13a Capitol Hi l l 14 T17 Richmond South 121 490831 1230828 10 Richmond Nat.Pk 14 T26 North Shore 51 491928 1230458 8a Capilano 16 T27 Langley Central 105 490546 1223359 24 Lanley City 10 T28 Abbotsford 65 490258 1221733 37 Mills Lk. Clearbr. 11 T9 Rocky point park * 82 491651 1225053 13b Rocky Pt. Pk. 15 T12 Chilliwack 16 490909 1215703 44 Chillwack Mtn. 7 T15 Surrey east 65 490758 1224136 20 Tynehead Pk. 12 T16 Pitt meadows 54 491246 1224228 23 Derby Reach 12 Tab. C3: S0 2 direct measurements for 1993 and matched moss samples from Fraser Valley 1993 collection (S02 in ug/m3). Data from GVRD (1994). GVRD GVRD GVRD GVRD GVRD Moss Moss Metal Stat. # Station name Lat. Long. S02 Site* Location Index TI Robson Square 491658 1230714 8 3a Stanley 15 T2 Kits, 2550W10th 491545 1230945 5 4a Uel 10 T4 Kensington Pk 491645 1225811 5 13a Capitol 14 T5 Confederation Pk. 491700 1225952 5 13a Capitol 14 T6 Second Narrows 491808 1230108 6 13a Capitol 14 T7 Anmore Elementary Rd. 491840 1225130 4 18 Coquitlam City 12 T9 Rocky Point Park 491651 1225053 4 13b Rocky Pt.Pk . 15 T10 Port Moody 491705 1224926 3 18 Coquitlam City 12 T12 Chilliwack Works Yard 490909 1215703 44 Chilliwack Mtn. 7 T16 Pitt Meadows (Airport) 491246 1224228 1 20 Tynehead Pk 12 T17 Richmond South 490831 1230828 1 10 Richmond N . Pk 14 T18 Burnaby South 491256 1225857 3 14b Fraser River Pk 16 T26 Mah on Pk, North Van 491928 1230458 4 8a Capilano 16 168 Tab. C 4 : N 0 X direct measurements for 1993 and matched moss samples (NOx in ug/m3). NO x includes nitric oxide (NO) and nitrogen dioxide (NOx). (GVRD 1994). GVRD GVRD GVRD GVRD GVRD Moss Moss Metal Stat# Station name Lat. Long. N O x site # Location Index TI Robson Square 491658 1230714 91 3a Stanley 15 T2 Kits, 2550 WlOth 491545 1230945 83 4a Uel 10 T3 Marpole 491235 1230650 159 4b Macdonald 15 T4 Kensington Pk 491645 1225811 51 13a Capitol 14 T5 Confederation Pk. 491700 1225952 47 13a Capitol 14 T6 Second Narrows 491808 1230108 47 13a Capitol 14 T7 Anmore Elementary 491840 1225130 17 18 Coquitlam City' 12 T9 Rocky Point Park 491651 1225053 62 13b Rocky Pt.Pk 15 T10 Eagle Ridge, Port Moody 491705 1224926 50 18 Coquitlam City 12 T12 Chilliwack Works Yard 490909 1215703 31 44 Chilliwack Mtn. 7 T13 North Delta 490930 1225403 45 15 Delta 12 T14 Burnaby Mtn. SFU 491645 1225442 20 13d Belcarra 15 T15 Surrey East 490758 1224136 22 24 Langley City 10 T16 Pitt Meadows (Airport) 491246 1224228 38 20 Tynehead Pk 12 T17 Richmond South 490831 1230828 63 10 Richmond Nat Pk 14 T18 Burnaby South 491256 1225857 55 14b Fraser River Pk 16 T19 Richmond East 491105 1230228 62 10 Richmond Nat. Pk 14 T20 Burnaby East 491220 1225707 82 14a Burnaby Lk. 14 T26 Mahon Pk, North Van 491928 1230458 45 8a Capilano 16 T27 Langley Central 490546 1223359 19 24 Langley City 10 T28 Downtown Abbotsford 490258 1221733 48 37 Mills Lake 11 C 2: Correlat ion between moss method and direct a i r measurements Tab .C5: Spearman rank correlation coefficient r s for metal concentrations from matched moss samples from the Fraser Valley 1993 collection and direct air measurement data for particulates, air quality index, S0 2 , and NO x (GVRD 1994). Tests were carried out individually (particulates - n = 40, aqi - n = 10, S0 2 - n = 15, NO x - n = 21). * = significant at p<0.05, ** = significant at p<0.01. Particulate AQI so2 NO x Pb 0.093 0.055 0.318 0.185 Cd 0.290 -0.179 -0.171 0.369 Cr 0.432** 0.435 -0.069 0.443* Ni 0.127 0.234 0.293 0.173 Zn 0.356* 0.340 -0.299 0.451* Mn 0.203 0.357 -0.257 0.223 169 APPENDIX D: THE GVRD GRIDDED EMISSION MODEL The Air Quality and Source Control Department of the GVRD estimates particulate, SO2, NOx, CO and VOC emissions for the Lower Fraser Valley. Emissions from area sources, point sources, traffic and off-road traffic are taken into account. Estimated emissions are calculated for 5x5 km grid squares. Area source, traffic, and off-road traffic related emissions are calculated for the gridsquares A l - K24 (Fig. Dl). Point source emissions are only estimated for the GVRD area from A l - K l l . All estimations are based on 1990 data. Point sources include: Bulk shipping and terminals, chemical manufacturing, electric power generation, metal foundries, metal fabrication, municipal solid waste incineration, non-metallic mineral processing (predominantly cement production), paper and allied products industries, petroleum refining, wood products, and other industries Area sources include: Space heating (residential, commercial, industrial, institutional), burning, agriculture, natural sources, solvent evaporation, landfills, and other processes. Traffic sources include: Light duty vehicles and heavy duty vehicles. Off - road sources include: Railways, ships, and planes. The estimated emission values for the gridsquares is presented in Table D l for pointsources, in Table D2 for area sources, in Table D3 for traffic and in Table D4 for off-road sources. In order to compare the modelled emissions to the metal concentrations found in the present study each "gridsquare emission estimate" was matched with the nearest moss sample (Tab. D l - D4). The data sets were correlated with a spearman rank correlation test. The null hypothesis "no correlation" was rejected if p<0.05. The GVRD published a report on basis of this model, which indicates the percentage of pollutants emitted from each source for the GVRD district. Traffic and off-road sources were grouped as mobile sources. These estimations are presented in figure D2 - D5. 170 171 Tab. Dl: Point source emission estimates from the GVRD gridded emission model and matched moss samples from the Fraser Valley 1993 collection of the present study.(indicates gridsquares to which no moss sample was matched, because the nearest mosssample was already matched with another gridsquare). Grid Point Point Point Point Point Moss Moss Cell C O NOx Part SOx V O C site# Location B06 204.35 7.40 45.28 1.26 13.57 l i b Pt.Roberts B13 0.08 0.40 10.90 0.02 0.03 25 Campbell Park B14 0.37 1.87 6.61 0.05 4.64 33 Aldergrove Park C04 0.29 1.16 0.01 2.47 0.01 * C05 1.44 5.75 253.91 0.76 2.22 37 Mills Lake C12 0.25 0.09 3.54 0.04 0.10 11a Ladner Harbour Park C13 .0.06 1.29 0.96 0.02 0.02 28 Glenvalley D04 8.32 0.29 2.08 1.03 3.31 * D05 2.44 41.55 32.25 0.22 210.37 * D06 19.53 10.61 510.34 1256.97 603.51 * D07 112.17 5113.38 128.86 0.64 7.42 * DOS 6.17 3.42 127.97 0.73 12.75 * D09 572.70 7.49 75.69 6.33 89.03 * D13 10.40 3.69 6.21 0.06 0.69 * E04 39.93 0.27 117.30 5.68 85.14 * E05 530.31 36.13 1236.19 28.20 836.48 10 Richmond Nature Park E06 231.92 111.41 353.57 7.45 115.50 * E07 491.92 25.29 933.85 131.26 409.59 14b Fraser River Park EOS 3.20 845.42 313.36 0.31 23.29 15 Delta E10 0.33 14.13 255.15 0.04 8.87 20 Tynehead E l l 11.89 1.63 . 254.67 1.15 29.69 23 Derby Reach E13 3.50 0.21 73.16 0.25 0.58 * F03 0.11 14.01 0.48 0.47 0.24 4b Macdonald F05 0.18 0.73 15.08 0.31 131.29 * F06 0.16 1.83 12.79 0.05 24.19 * F07 1.83 1.28 103.29 0.13 87.98 14a Burnaby Lake F08 2491.64 6.64 816.59 27.46 248.61 * F09 1.27 320.48 51.63 0.44 0.20 * F10 0.16 5.08 28.78 0.02 40.62 * G04 3.81 0.78 5.59 0.32 12.36 4a Uel G05 24.87 16.47 571.19 5.31 64.32 3a Stanley G06 5.16 40.35 528.26 11.21 29.06 9 Trout Lake G07 208.98 20.60 217.01 1665.68 3494.23 13a Capitol G08 297.40 445.88 87.95 141.30 718.35 13b Rocky Pt.Park G09 787.98 652.22 109.16 5.20 73.54 19 Mundy Park G10 0.42 92.68 61.51 5.41 26.18 18 Coquitlam city H05 7.07 47.21 997.54 0.11 51.21 8a Capilano H06 24.95 6.34 • 955.21 15.44 25.97 8b Lynn Canyon H08 141.12 270.03 133.19 438.15 674.94 13d Belcarra H10 4.05 350.30 19.90 0.08 2.97 22 Burke Mtn. 172 Tab. D 2 : Area source emission estimates from the GVRD gridded emission model and matched moss samples from the Fraser Valley 1993 collection of the present study. Gr id Cell Area C O Area NOx Area Part Area SOx Area V O C Moss Site* Moss Location A06 0.00 656.85 2.71 2.37 0.11 l i b Pt.Roberts A l l 0.00 661.89 1.75 1.37 0.11 25 Campbell Park A14 0.00 44.23 14.86 0.38 0.41 33 Aldergrove Park B09 0.03 38.18 32.25 46.62 0.10 21 Crescent Park B17 88.80 159.22 0.27 3.78 20.53 37 Mills Lake C05 32.93 25.60 36.22 17.83 1.79 11a Ladner Harbour Park C l l 1.92 28.43 18.50 9.62 77.45 24 Langley C19 20.94 87.33 154.35 7.20 0.00 40 Sumas Mtn. C22 166.53 1.12 22.97 109.04 0.08 45 Vedder Peak C24 20.70 94.57 173.46 11.55 0.00 50 Tamalii D18 121.18 0.72 78.73 29.10 0.23 36 Matsqui Trail D21 20.10 5.60 474.31 279.80 0.02 44 Chilliwack Mtn. D24 22.50 121.74 29.20 19.59 0.05 49 Nixon Road E05 7.07 0.00 24.16 16.02 0.05 10 Richmond Nature Park E07 2.14 0.00 233.58 329.28 0.02 14b Fraser River Park EOS 0.05 0.00 132.04 17.87 0.85 15 Delta E10 0.16 0.00 14.20 4.65 0.05 20 Tynehead E12 0.04 0.02 240.38 61.06 0.02 23 Derby Reach E20 0.16 315.82 6.01 4.01 0.10 39 Deroche F04 0.00 46.98 22.84 13.96 0.31 4b Macdonald F07 0.00 444.32 180.10 0.80 0.04 14a Burnaby Lake F13 0.00 31.73 47.69 8.86 0.01 27 Kananaka F15 0.00 3.62 11.42 0.05 0.16 31 Rolley Lake F23 63.76 55.53 17.59 , 0.64 0.00 48 Mt.Wood G03 27.21 119.45 222.34 0.01 0.00 4a Uel G06 145.93 4.55 2.72 0.11 0.00 9 Trout Lake G07 42.56 294.72 0.81 0.04 0.00 13a Capitol G09 44.60 23.87 16.82 0.31 0.00 19 Mundy Park G13 38.04 77.75 199.77 0.00 3.34 26 U B C research G18 45.98 71.84 98.37 0.28 5.90 34 Sylvester road H03 111.03 195.39 0.02 115.14 0.12 3b Lighthouse park H07 266.11 1.11 1.69 7.95 0.08 13c Seymour headquarters H08 98.49 129.90 0.12 2.54 0.02 13d Belcarra H09 23.42 73.43 133.92 0.78 0.00 18 Coquitlam city H10 27.12 18.06 42.03 60.50 0.00 22 Burke Mtn. H14 23.93 60.38 117.57. 3.73 0.00 30 Golden Ears H21 1.90 6.27 13.61 60.68 10.75 ' 42 Statlu H23 65.90 147.61 0.92 10.92 0.02 '47 Weaver Lake 104 48.61 117.51 0.00 10.52 0.02 . 2 Cypress 105 18.61 90.99 0.00 3.56 0.00 8a . Capilano 106 10.14 21.99 0.00 231.33 0.00 8b Lynn Canyon 110 13.81 85.23 0.00 3.55 0.23 . 17 Coquitlam Lake J01 9.83 0.00 1537.95 1.48 0.03 1 Bowen Island J23 0.12 33.30 66.09 7.52 0.48 46 Harrison K03 0.00 83.34 101.48 18.47 0.00 Howe A Lions Bay 173 Tab. D 5 : Spearman rank correlation coefficients (rs) for emission estimates from the GVRD gridded emission model and metal concentration from the matched moss sites from the present study (* = significant at p<0.05, ** = significant at p<0.01, *** = significant at p<0.001). Point sources (n=23) were tested separatly from area, traffic, and off-road emission sources (n = 45). Pb Cd Cr Ni • Zn Mn CO point 0 . 5 3 8 * * 0 . 2 2 1 0 . 3 7 5 0 . 4 2 1 * 0 . 3 8 7 0 . 1 8 8 NOx point 0 . 3 9 3 0 . 2 3 6 0 . 1 0 7 0 . 2 6 7 0 . 3 3 1 - 0 . 0 6 7 Particles point 0 . 5 4 1 * * 0 . 3 9 7 0 . 3 9 1 0 . 3 7 9 0 . 3 1 1 0 . 2 9 5 SOx point 0 . 5 4 5 * * 0 . 3 1 5 0 . 5 0 5 * 0 . 5 5 2 * * 0 . 4 4 8 * - 0 . 0 4 9 VOC point 0 . 6 8 8 * * * 0 . 2 2 9 0 . 5 0 2 * 0 . 4 8 6 * 0 . 5 2 5 * 0 . 1 8 8 CO area 0 . 1 8 4 0 . 1 9 5 - 0 . 0 2 3 0 . 1 6 0 0 . 2 7 0 - 0 . 1 7 7 NOx area - 0 . 0 0 5 - 0 . 1 5 9 - 0 . 1 9 8 - 0 . 0 3 5 - 0 . 1 7 9 0 . 0 6 0 Particles area - 0 . 2 5 6 - 0 . 1 8 4 0 . 2 1 9 - 0 . 1 2 6 - 0 . 2 2 4 - 0 . 1 5 6 SOx area - 0 . 0 4 9 - 0 . 0 5 7 0 . 2 7 3 0 . 1 7 5 0 . 0 0 7 - 0 . 1 4 2 VOC area - 0 . 1 6 8 - 0 . 1 0 1 0 . 0 4 9 - 0 . 1 6 3 - 0 . 1 1 4 0 . 0 6 0 CO traffic 0 . 4 4 4 * * 0 . 3 2 5 * 0 . 4 1 9 * * 0 . 5 7 5 * * * 0 . 6 1 1 * * * - 0 . 0 5 3 Nox traffic 0 . 4 3 6 * * 0 . 3 1 8 * 0 . 4 3 5 * * 0 . 5 7 7 * * * 0 . 5 9 9 * * * - 0 . 0 8 4 Particles traffic 0 . 4 0 9 * * 0 . 2 9 5 * 0 . 4 2 8 * * 0 . 5 4 8 * * * 0 . 5 5 8 * * * - 0 . 0 6 3 Road dust 0 . 4 3 8 * * 0 . 3 2 4 * 0 . 4 2 9 * * 0 . 5 7 7 * * * 0 . 6 0 7 * * * - 0 . 0 7 9 SOx traffic 0 . 4 1 2 * * 0 . 2 9 8 * 0 . 4 3 1 * * 0 . 5 5 0 * * * 0 . 5 6 0 * * * - 0 . 0 6 6 VOC traffic 0 . 4 4 4 * * 0 . 3 2 5 * 0 . 4 1 9 * * 0 . 5 7 5 * * * 0 . 6 1 1 * * * - 0 . 0 5 3 CO offroad 0 . 4 5 2 * * 0 . 3 2 9 * 0 . 2 9 2 0 . 5 7 4 * * * 0 . 6 3 6 * * * - 0 . 1 1 6 NOx offroad 0 . 3 3 2 * 0 . 1 6 6 0 . 2 9 0 0 . 4 6 9 * * 0 . 4 9 9 * * * - 0 . 2 4 6 Particles offroad 0 . 2 0 1 0 . 0 8 7 0 . 3 9 3 * * 0 . 3 7 6 * 0 . 3 4 5 * - 0 . 3 0 8 SOx offroad 0 . 3 3 3 * 0 . 1 9 7 0 . 3 1 2 * 0 . 4 6 9 * * * 0 . 5 2 9 * * * - 0 . 2 6 9 VOC offroad 0 . 4 2 3 * * 0 . 2 9 8 * 0 . 2 8 5 0 . 5 5 5 * * * 0 . 6 2 4 * * * - 0 . 1 2 1 176 VOC 11% 36% Area Sources Point Sources Mobile Sources Gasoline Marketing 46% Fig. D2: Percentage of pollutants emitted by the area, point and mobile source and gasoline marketing. Estimates are for the G V R D area in 1990 (from G V R D 1993b). 177 CO NOx 5% 3% 3 1 % 4 3 % 3 % 5% 4% s o / < 12% 5% 58% PARTICULATE 4% 25% 4 3 % 60% 3 3 % 6% 6% VOC 20% 7% 56% Bulk Shipping and Terminals Chemical Manufacturing Electric Power Generation Metal Foundries and Metal Fabrication M SW Incineration Non-Metallic Mineral Processing Paper and Allied Products Petroleum Refining Wood Products Other Fig. D 3 : Percentage of pollutants emitted by the various point sources. Estimates are for the G V R D area in 1990 (from G V R D 1993b). 178 CO NOx Fig. D4: Percentage of pollutants emitted by the various area sources. Estimates are for the GVRD area in 1990 (from GVRD 1993b). 179 86% Fig. D5: Percentage of pollutants emitted by the various mobile sources. Estimates are for the G V R D area in 1990 (from G V R D 1993b). 180 

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