SAN FRANCISCO, Feb. 19, 2020 — A federal district court today ordered the Environmental Protection Agency to either approve or force improvements to California’s plans to reduce soot in Plumas County, north of Lake Tahoe and smog in Ventura County.

The court also ordered the EPA to act on Arizona’s plan to curb dangerous smog in Phoenix. The agency must address both plans by March 1, 2021.

Today’s decision, issued by the U.S. District Court for the Northern District of California, is the result of a 2019 lawsuit brought by the Center for Biological Diversity and the Center for Environmental Health. It will trigger action required under the Clean Air Act to reduce dangerous air pollution in areas that are home to more than 4 million people.

“Today’s decision is an important win in the ongoing fight for clean air and in forcing EPA to carry out its duties to rein in air pollution,” said Caroline Cox, research director at the Center for Environmental Health. “The EPA’s shameful delays have jeopardized the lives of hundreds of thousands of Arizona and California residents who suffer with serious breathing and health problems.”

Pollution from ozone, also known as smog, and the particulate matter known as soot can cause asthma and other respiratory diseases, cardiovascular disease, reduced lung function and vision impairment.

An EPA study found that Clean Air Act programs to reduce fine particle pollution and ozone pollution prevented more than 160,000 deaths, 130,000 heart attacks and 1.7 million asthma attacks in 2010 alone.

Today’s action will also help protect wildlife and entire ecosystems. Ponderosa pines in Southern California and Arizona, for example, are particularly sensitive to smog pollution, which can stunt growth, interfere with photosynthesis and increase risks from disease, weather and insects, according to the EPA.

“We’re facing a heartbreaking extinction crisis,” said Robert Ukeiley, an attorney at the Center for Biological Diversity. “To give our most imperiled plants and animals a better chance at survival, the EPA has to do its job and ensure these species are not choking on toxic air.”