October 29, 2024 – WASHINGTON – A federal judge approved a legal agreement on Monday requiring the Environmental Protection Agency to update air quality standards by November 10, 2028, that protect people from toxic nitrogen air pollution.

Federal law requires the EPA to review the pollution standards every five years and improve them as needed to ensure they protect public health. The agency has not reviewed the standards since May 2018 and has not updated them since 2010, despite new scientific evidence showing greater harms from nitrogen pollution than were previously realized.

“Under this agreement, the EPA can no longer skirt its duty to address nitrogen pollution’s significant harms to people and the environment,” said Jeremy Nichols, a senior advocate at the Center for Biological Diversity. “This requires the agency to do the bare minimum, which is to comply with the Clean Air Act’s very reasonable requirements for reducing the environmental damage caused by this dangerous air pollution.”

Nitrogen pollution is linked to a range of health problems, including increased risk of lung and heart disease, diabetes, birth problems, cancer and even death. This pollution also leads to excess nitrates in drinking-water supplies and soils, causing toxic algal blooms and harm to plants and wildlife.

Since the EPA last updated the standards in 2010, the research linking nitrogen oxides to a variety of health harms has only become stronger. For example, recent studies have suggested a connection between nitrogen pollution and higher rates of dementia, even at pollution levels below the current standards. It’s also been linked to depression and worse COVID outcomes.

“Since the EPA’s last review of these pollution standards, the science behind nitrogen air pollution’s serious health harms has become more certain,” said Tom Fox, senior legislative counsel at the Center for Environmental Health. “The EPA needs to catch the standards up with the science, as required by the law. It’s tragic that the agency is years behind schedule, even with this agreement.”

Nitrogen oxides result from burning fossil fuels at sources like power plants and cars. This pollution transforms into ozone pollution, also known as smog, and soot pollution.

“For years, the EPA has stalled on updating its nitrogen oxide air pollution standards while polluters reaped the financial benefits at our communities’ expense,” said Joshua Smith, senior attorney at the Sierra Club. “We believe stronger standards are long overdue, and we are glad to see the EPA finally take action and prioritize public health. We urge the agency to act swiftly.”

The agreement also requires the EPA to finalize its review of the scientific evidence showing the harms nitrogen pollution does to human health by September 30, 2026.

Monday’s agreement, between the EPA and the Center for Biological Diversity, Center for Environmental Health and Sierra Club, was approved by U.S. District Judge Rita F. Lin in the U.S. District Court for the Northern District of California.

The agreement and the 2023 lawsuit it resolves are part of an ongoing effort to compel the EPA to protect people and the environment from air pollution, including nitrogen pollution, in compliance with the Clean Air Act.

More information about the fight against air pollution is available at Protecting Air Quality Under the Clean Air Act.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.7 million members and online activists dedicated to the protection of endangered species and wild places.

The Center for Environmental Health works with parents, communities, businesses, workers, and government to protect children and families from toxic chemicals in homes, workplaces, schools, and neighborhoods.

The Sierra Club is America’s largest grassroots environmental organization, with millions of members and supporters. In addition to protecting every person's right to get outdoors and access the healing power of nature, the Sierra Club works to promote clean energy, safeguard the health of our communities, protect wildlife and preserve our remaining wild places through grassroots activism, public education, lobbying and legal action.

Source: Center for Biological Diversity