rmdingler shares a report: When you drive, tiny bits of plastic fly off your tires and brakes. Now scientists have shown how all that road muck is blowing into environments like the Arctic. When the world fully transitions from cars that run on dinosaur juice to cars that run on electricity, humanity will have eliminated a major source of planet-warming carbon dioxide and a major threat to human health — air pollution kills nearly 550,000 children under age 5 each year. But a hidden environmental threat from cars will persist, and perhaps get worse as more of the world enters the middle class, putting more vehicles on the road: the microplastics that shear off cars’ tires and brakes. Tires are made of rubber but also contain synthetic elastomers and fibers to improve stability; brakes are a mixture of metal and plastic. Little fragments of these materials erode with friction whenever rubber meets the road or you hit the brakes, and these pieces end up in the gutter. Later, they wash out to sea in rainwater, or get caught up in the wind.
Today in the journal Nature Communications, researchers model how microplastics from our cars are traveling from densely populated regions into the environment. These little automotive bits pour from the cities of Europe, Asia, and the Americas, and settle out in the Arctic, Greenland, and the world’s oceans. The researchers find that the mean lifetime for the smallest particles, which more easily get caught up in winds, is nearly a month. Their modeling calculates that 52,000 tons of the smallest particles end up in the sea each year, and 20,000 tons end up in remote snowy and icy regions. “Small particles are lofting higher, of course. But they also weigh less than larger ones and can easily reach remote regions under favorable meteorological conditions,” says Nikolaos Evangeliou, senior researcher at the Norwegian Institute for Air Research and lead author of the new paper. “Larger particles are usually deposited near the sources.” Slashdot reader rmdingler adds: “Reducing CO2 emissions and other airborne pollutants are certainly steps in the right direction, but it seems like there’s a new environmental toxin around every corner.”