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Researchers work to understand how our plastic waste affects the Great Lakes

Mar 26, 2015

There’s plastic trash in every one of the Great Lakes.

That plastic includes junk people leave at the beach, microbeads from consumer products such as shower gel, face wash and toothpaste, and pellets from plastic manufacturing.

Researchers at the University of Waterloo in Ontario say it’s a growing problem and they say we don’t know enough about that plastic garbage.

Phillippe Van Cappellen is a professor of Earth and Environmental Sciences at the University of Waterloo. He and his colleagues reviewed studies of plastic garbage in the lakes and they examined data from beach cleanups. Their study is published in the Journal of Great Lakes Research.

Van Cappellen says there are major gaps in our understanding of plastic pollution in the Great Lakes. For one thing, he says we need to better understand how plastic is distributed throughout the lakes.

“We also don’t know how much of it ultimately accumulates in the bottom sediments of the lakes. And then, of course, there’s also the extent of the bioaccumulation of plastics in the food chain, and also the potential transfer of pollutants with these plastics into the food chain.”

Van Cappellen says studies suggest Lake Erie has the highest concentration of plastic debris.

University of Waterloo grad student Alex Driedger collects water samples.
Credit Courtesy of University of Waterloo

"That is probably due to the fact that the population density in the basin of Lake Erie is higher, and also there’s more industry in the basin of Lake Erie compared to some of the other lakes, particularly if we compare it to Lake Superior,” he says.

Risks to wildlife

Van Cappellen says wildlife can get entangled by large pieces of plastic. But he says there might be a bigger problem emerging.

“We’re particularly concerned about the smaller ones, what we call microplastic, because those are easily ingested by wildlife: fishes, marine mammals, and also by shellfish. And the smaller particles, which have relative to their mass, a higher surface area, can also be the ones that tend to absorb certain pollutants that are present in the environment.”

Microbeads are so tiny they get washed down the drain, pass through sewage treatment plants, and end up in rivers and lakes.

Van Cappellen says other studies around the world have found microplastics in the bodies of marine wildlife. Fish and mammals can mistake the tiny beads for food.

“We know that they actually do end up sometimes in the muscle tissue of fish and shellfish and that’s the part that we humans eat, so there’s certainly some potential risk involved for human health, but we don’t know very much about it, so it’s still an open area in terms of research.”

So what do we do about this?

Lawmakers in several states are taking action to ban the sale of products containing microbeads. Several cosmetics companies have pledged to replace microbeads with natural substances such as oatmeal, ground-up fruit pits and sea salt.

This week, in Canada, the New Democratic Party in Parliament introduced a motion calling for a ban on microbeads, as The Globe and Mail reports:

New Democrats also want the federal government to list microbeads as a potential toxic substance. During Tuesday’s debate, NDP MPs accused the Conservatives of “gutting” the Environmental Protection Act that protects Canada’s lakes and rivers.

The Alliance for the Great Lakes has some guidelines on microbeads. One of their tips: look for the ingredients "polyethylene" or "polypropylene" in your personal care products to know whether they contain microbeads.