Open Collections

McCarty, Kevin

University of British Columbia

Approximately 1.5 billion tires/year are produced worldwide. Tire tread wear particles due to road abrasion are a major source of environmental microplastic pollution and 5.9 million tonnes/year of tire and road wear particles (TRWP) are emitted globally. Twelve to twenty percent of TRWP are transmitted into surface waters, where they can leach (i.e., release) chemical compounds that can adversely affect aquatic species. The primary objective of this study was to assess the acute, freshwater ecological risk of TRWP emissions. A conceptual ecological risk assessment (ERA) model was developed using ERA frameworks. The model was applied to Kalamalka Lake with respect to British Columbia (BC) Highway 97 (HWY-97) in Western Canada. This was the first ERA of TRWP in Canada and the results and methodology will provide a foundation for future research. This was a screening-level, conceptual ERA, based on secondary data from published scientific studies. Two spatial scenarios were assessed. Spatial scenario 1 assumed annual TRWP emissions from 20 km of HWY-97 equilibrate across the entire lake volume. Spatial scenario 2 assumed TRWP emission from a single storm drain microcatchment (0.875 km of HWY-97) equilibrated adjacent to the shoreline in a smaller water volume in the short-term. For both scenarios, TRWP-derived chemical leachates considered for ERA were aniline, anthracene (ANT), benzo(a)pyrene (B(a)P), fluoranthene (Fl), mercaptobenzothiazole (MBT), and zinc (Zn). An assumed ‘total TRWP-derived leachate set’ was also assessed, based on data representing all compounds present in tire-derived leachate solution tests. The results indicated a potential risk to aquatic species in both spatial scenarios, depending on the contaminant of concern. In Scenario 1, ecotoxicity risk was high from exposure to zinc and the total TRWP-derived leachate set. Scenario 2 results indicated acute risk was high from all TRWP-derived chemicals examined, except MBT. This preliminary screening of ecological risk provides an early signal that freshwater lakes adjacent to busy highways may be at risk from TRWP contamination, demonstrating a need for further research and additional data to verify the results.

Text

2022-11-23

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/83291

Civil Engineering

University of British Columbia

UBCO

http://creativecommons.org/licenses/by-nc-nd/4.0/