The Tyre collective designed a device that can collect tire emissions. According to them the tires in electric vehicles also emit emissions as the rubber meets the road. Hanson Cheng is one of the three co-founders of the London-based startup.
The tires on most passenger vehicles contain little natural rubber. Instead, they’re made from a stew of petrochemicals, particles of which ultimately wind up in the soil, air, waterways, and oceans. The International Union for Conservation of Nature pegs tires as the second leading source of microplastic pollution in oceans, and one 2017 study found a global per capita average of .81 kilograms in tire emissions per year, ranging from .23 kg per year in India to 4.7 kg (roughly 10 pounds) in the US. That may seem minor stacked up against the nearly 300 pounds in plastic waste the average American generates each year, but microplastics are tiny by definition — and an insidious source of toxins that researchers are only beginning to understand.
“When we talk about zero emissions, a lot of that conversation is about electric vehicles,” says Cheng, 30. “But there’s a whole world of non-exhaust emissions that also needs to be addressed.”
Switching to electric cars helps to lower carbon emissions — even after accounting for manufacturing and charging batteries — but it actually exacerbates the problem of tire emissions. EVs typically weigh more and accelerate faster than their gas-burning counterparts, which adds to tire wear. The EV transition will also keep the world’s fleet of cars growing until nearly 2040, well after the peak for gas-burning cars that are expected in the next two years, according to BloombergNEF, a clean energy research group.
“Most of these EVs are big monstrous things, so it’s perfectly intuitive that they will be chewing up tires faster,” says Nick Molden, founder, and CEO of the UK-based research shop Emissions Analytics. Results from the company’s latest road tests, published in May, show that under normal driving conditions a gas car sheds about 73 milligrams per kilometer from four new tires. A comparable EV, the company estimates, sheds an additional 15 milligrams per kilometer, or about 20% more.
For decades, tailpipe emissions — both the greenhouse gases that contribute to global warming and the particulates that cause air pollution — have overshadowed the tire problem. That means researchers are only beginning to catalog what’s even in tire emissions. Across the different tires it studied, Emissions Analytics found an average of more than 400 organic compounds. “Part of the work we’re doing is to try to resolve what on earth these compounds are,” Molden says. “If we can’t identify them, then we can’t even fathom what the toxicity may or may not be.”