Excerpt:
Most tires are made of synthetic rubber that sheds particles of microplastics over time.

Every few years, the tires on your car wear thin and need to be replaced. But where does that lost tire material go?

The answer, unfortunately, is often waterways, where the tiny microplastic particles from the tires’ synthetic rubber carry several chemicals that can transfer into fish, crabs and perhaps even the people who eat them.

We are analytical and environmental chemists who are studying ways to remove those microplastics – and the toxic chemicals they carry – before they reach waterways and the aquatic organisms that live there.

Microplastics, macro-problem

Millions of metric tons of plastic waste enter the world’s oceans every year. In recent times, tire wear particles have been found to account for about 45% of all microplastics in both terrestrial and aquatic systems.

Tires shed tiny microplastics as they move over roadways. Rain washes those tire wear particles into ditches, where they flow into streams, lakes, rivers and oceans.

Along the way, fish, crabs, oysters and other aquatic life often find these tire wear particles in their food. With each bite, the fish also consume extremely toxic chemicals that can affect both the fish themselves and whatever creatures eat them.

Some fish species, like rainbow trout, brook trout and coho salmon, are dying from toxic chemicals linked to tire wear particles.

Researchers in 2020 found that more than half of the coho salmon returning to streams in Washington state died before spawning, largely because of 6PPD-Q, a chemical stemming from 6PPD, which is added to tires to help keep them from degrading…