Microplastics and Anthropogenic Particles in Recreationally Caught Freshwater Fish from an Urbanized Region of the North American Great Lakes.

Background: Microplastics are a pervasive contaminant cycling through food webs-leading to concerns regarding exposure and risk to humans.

Objectives: We aimed to quantify and characterize anthropogenic particle contamination (including microplastics) in fish caught for human consumption from the Humber Bay region of Lake Ontario. We related quantities of anthropogenic particles to other factors (e.g., fish size) that may help in understanding accumulation of microplastics in fish.

Methods: A total of 45 samples of six fish species collected from Humber Bay in Lake Ontario near Toronto, Ontario, Canada, were examined for anthropogenic particles in their gastrointestinal (GI) tracts and fillets. Using microscopy and spectroscopy, suspected anthropogenic particles were identified and characterized.

Results: We observed anthropogenic particles in the GI tracts and fillets of all species. Individual fish had a $\text{mean}\pm \text{standard\hspace{0.17em}deviation}$ of $138\pm 231$ anthropogenic particles, with a single fish containing up to 1,508 particles. GI tracts had $93\pm 226$ particles/fish ($9.8\pm 32.6$ particles/gram), and fillets had $56\pm 61$ particles/fish ($0.5\pm 0.8$ particles/gram). Based on a consumption rate of 2 servings/week, the average yearly human exposure through the consumption of these fish fillets would be $\mathrm{12,800}\pm \mathrm{18,300}$ particles.

Discussion: Our findings suggest that consumption of recreationally caught freshwater fish can be a pathway for human exposure to microplastics. The elevated number of particles observed in fish from Humber Bay highlights the need for large-scale geographic monitoring, especially near sources of microplastics. Currently, it is unclear what the effects of ingesting microplastics are for humans, but given that recreationally caught freshwater fish are one pathway for human exposure, these data can be incorporated into future human health risk assessment frameworks for microplastics. https://doi.org/10.1289/EHP13540.