You haven't worried about this yet, have you?

Plastic Is Falling From the Sky. But Where’s It Coming From?

When a car rolls down a road, tiny flecks fly off its tires as part of normal wear and tear. This material isn’t pure rubber; it contains added synthetic rubbers and a slew of other chemicals. Tire particles, then, are technically microplastics, and they’re all over the place. One study in 2019 calculated that 7 trillion microplastics wash into San Francisco Bay each year, most of it from tires.

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