“They account for 28% of microplastics entering the environment globally.”
Vehicles shed an estimated 6 million tons of tire fragments a year, and more than 2 billion new tires are made annually. Zinc oxide makes up about 0.7% of each tire’s weight and goes out with the dust. Tire particles still aren’t treated as a pollution category of their own. A quarter of the problem rolls past regulators on four wheels.