Microbeads are not harmful when used directly, but issues arise once they are washed down the drain. They are so small that they can make it through most water treatment plants that don't have filter systems designed to catch minuscule particles. The plastic fragments then make their way into lakes, rivers and streams, where they can be ingested by water-dwelling organisms such as fish.
Those environmental concerns have led Loblaw Companies Ltd. to voluntarily announce that it will stop making products with microbeads by 2018 as momentum continues to mount for a complete ban.
Contaminants can accumulate
"The concern is that these microbeads then make it up the food chain," said Philippe Van Cappellen, an ecohydrology professor at the University of Waterloo who spoke to CBC's The Morning Edition in March. "Since they're so small, they also have a large surface relative to their mass and certain contaminants that are present in the environment can actually preferentially accumulate on those microbeads."
Synthetic chemical compounds such as polychlorinated biphenyls and polycyclic aromatic hydrocarbons can accumulate on the plastic bits, according to Van Cappellen.
"Those are compounds that are known — or at least have been suggested — to be causing cancer or birth defects and those are contaminants that preferentially will accumulate on the surfaces on these little plastic particles."
Research shows that microplastics, including microbeads, carry these contaminants along the food chain, potentially allowing humans to consume them in food and water, Van Cappellen said. If a fish eats the plastic and someone eats the fish, the risk of being affected by these cancer-causing contaminants is real.
Scientists don't have direct evidence that microbeads pose a direct health problem for humans, but the concern is there, Van Cappellen says.
Calls for action
The potential danger is why environmentalists in Illinois successfully pushed for a ban on plastic microbeads in personal care products in 2014. It's also why U.S. House Rep. Frank Pallone introduced a bill to ban the products south of the border by 2018.
In Canada, Mayor Keith Hobbs of Thunder Bay, Ont., said microbeads in the Great Lakes is a "huge issue."
"We've had this on our radar for a few years now and ... we do discuss it at length [at] just about every meeting we have," he said in February.
A month after his comments, the Conservative government said Environment Canada was studying the dangers posed to wildlife and the environment by microbeads. The findings of the study will determine a federal-provincial action plan.
"The chemical management plan brought forth by our government will prioritize microbeads for assessment, which will benefit all Canadians," Colin Carrie, the parliamentary secretary to the environment minister, said in March.
The scientific review has yet to bring forth a change in government policy, so the NDP is calling for Ottawa to list microbeads as a potentially toxic substance.
"There is a real need to act. For the sake of our environment and our health, Canada must do as other countries have done and work to eliminate microbeads from everyday consumer products," said Brian Masse, the NDP's critic for the Great Lakes.
"The Conservatives promised to tackle this pollution problem; however, nothing concrete has yet been done," said Megan Leslie, the NDP's environment critic. "We want concrete action, now."
In May, Liberal environment critic John McKay introduced a private member's bill to ban the sale of personal care products that contain microbeads. He said his bill would "prevent some manufacturers from gaining an unfair advantage over companies that are showing leadership and phasing out this environmentally harmful ingredient."