A new study shows that Toronto’s Don River releases hundreds of billions of microplastic particles into Lake Ontario each year, raising concerns about pollution in one of Canada’s busiest watersheds.
Researchers estimate the river carries about thirty-six thousand kilograms of small plastic fragments annually, roughly equal to the weight of eighteen cars. The particles, often smaller than a grain of rice, come from construction foam, vehicle tires, and plastic packaging.
Scientists say microplastics are now found almost everywhere, including fish, soil and drinking water. These materials can affect wildlife growth and reproduction and may pose health risks to humans.
Experts link much of the Don River’s pollution to sewer overflows that occur during heavy rain. The city is investing billions to modernize its wastewater system and prevent future spills.
Researchers say reducing single-use plastics, improving stormwater management and controlling construction debris are key steps toward cleaner rivers and lakes.



