Seventy-five million people live in counties where the air breaks the federal soot standard, according to a recent white paper cited by Earthjustice. The group announced that the US Court of Appeals for the D.C. Circuit has now upheld that standard, the limit on fine particulate matter (PM2.5) that the Environmental Protection Agency tightened in 2024.
The ruling came after an unusual turn in the litigation. Corporations and attorneys general in allied states sued once the agency strengthened the rule. Last year, Earthjustice says, the EPA under President Trump stopped defending its own standard and asked the court to strike it down on narrow legal grounds, without disputing the science behind it. Health, environmental and community groups, along with a coalition of states led by California, stepped in to defend the standard themselves.
Earthjustice called the administration’s attempt to abandon the rule “unprecedented.”
What the standard does
The 2024 change lowered the annual limit from 12 to 9 micrograms per cubic meter. Soot is a mix of metals, organic chemicals and acidic substances small enough to be inhaled deep into the lungs and carried into the bloodstream. Vehicle exhaust, power plants and factories produce it. Earthjustice links it to premature death, cardiovascular harm, new and worsened asthma, lung cancer and neurological harm such as Alzheimer’s disease, with children, seniors and people with chronic illness most at risk.
By the EPA’s own estimate, as relayed by Shaun Goho of the Clean Air Task Force, the standard will prevent 800,000 cases of asthma symptoms, 2,000 hospital visits and 4,500 premature deaths in 2032. Earthjustice adds that the agency puts net health benefits as high as $46 billion by 2032, with costs an order of magnitude lower. The group says industry’s cost claims have been repeatedly debunked.
Voices from the groups that defended it
“Every day in practice, nurses witness and treat conditions made worse by soot pollution,” said Katie Huffling, executive director of the Alliance of Nurses for Healthy Environments, who listed asthma flare-ups, COPD, heart disease and preterm birth.
Noha Haggag of Environmental Defense Fund said the decision means “healthier, longer lives for people across the country.” Vijay Limaye of NRDC accused the EPA of dragging its heels while millions kept breathing unhealthy air.
Patrice Simms, Earthjustice’s vice president of healthy communities, said that “Lee Zeldin’s EPA must stop catering to polluters.” The Clean Air Act required the agency to formally identify areas violating the standard by February 6, 2026. It missed that date, and a group of health, environmental and community organizations and a state coalition have sued to force the step, which would require pollution cuts in those areas.
