The levels of microplastics found in fish around Toronto are higher than global averages, according to a recent study.
Researchers measured the level of microplastics found in fish gastrointestinal tracts (GI) and in fillets. Microplastics are defined in the report as small bits of plastic that can be up to five millimetres in size.
Freshwater fish, such as those that were part of the study, have been found to have higher levels of microplastics than marine fish. Citing a 2021 study, the authors said that freshwater fish have an average of 8 particles while marine fish average 2.7 particles.
In contrast, the researchers found an average of 138 particles per fish in Lake Ontario, which they said “greatly exceeds” the numbers in the 2021 study.
The authors note the results likely represent a “worst-case scenario,” for freshwater fish contamination because they looked at both the gut and the fillet of fish, when other studies often just look at the gut. They also caught the fish in a part of the lake known to be highly polluted.
Calculating based on the observed levels in the fillets, researchers estimated that people consume an average 123 particles of microplastics in a single serving of fish. Someone who ate two servings of Humber Bay fish fillets per week would ingest about 12,800 particles a year, the authors estimated.
“Our findings suggest that consumption of recreationally caught freshwater fish can be a pathway for human exposure to microplastics,” the report said.
Particles found in fish ranged from 2 in a largemouth bass to 1,503 in a white sucker.
Rubber bits were the most common type of particle researchers found in GI tracts, while non-rubber fragments were most common in the fish fillet.
The study notes that there was no evidence of bioaccumulation—plastic particles collecting in the fish over time.
Ontario’s Ministry of the Environment, Conservation and Parks told The Epoch Times in an email that the research helps it determine actions and commitments under Ontario’s Great Lake Protection Act and the 2021 Canada-Ontario Agreement on Great Lakes Water Quality and Ecosystem Health.
“The ministry studies emerging contaminants such as microplastics in fish to provide baseline information to help understand the degree of concern as risk information becomes available,” the email said.
