Your street – and your roof – may be polluting the air as much as your car

Extreme rising temperatures are known to increase the risk of environmental hazards like drought and wildfires. But new research published last week in Science Advances adds another danger to the list: extreme heat sends harmful emissions into the air courtesy of hot asphalt…The study, published by a team of Yale researchers, reveals that asphalt is likely an overlooked but major source of hazardous pollutants being released into the air.

“A main finding is that asphalt-related products emit substantial and diverse mixtures of organic compounds into the air, with a strong dependence on temperature and other environmental conditions,” says Peeyush Khare, a Yale chemical and environmental engineer and the lead author of the study…

On a typical summer day in Los Angeles, asphalt can reach to 140 degrees Fahrenheit. At this threshold, the asphalt will release a steady and significant stream of emissions. Under these conditions, scientists predict hot asphalt could become a long-lasting source of pollution…

Researchers estimated that in California’s South Coast Air Basin, the total amount of aerosols formed from hot asphalt emissions is comparable to those released by gas and diesel motor vehicles…

And in some environments, the pollution from asphalt can be higher than internal combustion engines powering our transport.