A coalition of environmental activists and advocacy groups is urging the Biden administration to toughen federal regulations around soot pollution, a step that they said could prevent thousands of deaths each year from respiratory disorders.

The coalition, organized by the Climate Action Campaign, drafted a letter to President Joe Biden earlier this week calling on federal officials to institute the most rigorous air quality standards for fine particulate matter, or PM 2.5, to denote bits of pollution smaller than 2.5 microns—about one-thirtieth the diameter of a human hair.

The current standard for particulate matter from soot pollution is 12 micrograms per cubic meter of air as an annual average. The advocacy groups asked Biden to toughen that standard to 8 micrograms per cubic meter.

Soot pollution has been linked to cardiac arrest, asthma attacks and what experts call “premature deaths” from a range of cardiovascular and breathing disorders. Most particulate matter is generated by vehicle exhaust, and emissions from power plants and other industrial operations.

“Each day that passes without updated limits is another day that millions of Americans are exposed to unhealthy and potentially dangerous levels of soot pollution,” the advocates wrote in a letter that was signed by more than 150 environmental groups from across the country.

The advocates cited a study released earlier this year by the Environmental Defense Fund, which found that as many as 19,600 deaths each year that are attributed to the harms of particulate matter could be avoided.

Margie Alt, campaign director of the Climate Action Campaign, noted that the federal standards on soot pollution have not been updated since 2012, and that over the past decade scientists have learned more about the potential adverse health effects related to particulate matter.

“We know the science is better and we know the technology is better,” Alt said in an interview. “We know that exposure to soot leads to increased mortality, leads to more hospitalizations and more visits to the emergency room. Asthma is the most obvious disease that’s triggered by it, but it can also trigger heart attacks and strokes and Parkinson’s and COPD”—chronic obstructive pulmonary disease—“and risk for preterm births and infant mortality.”

Alt said strengthening the standard for soot pollution is part of a broader campaign undertaken by her organization to ensure that emissions overall are reduced by at least half by the end of the decade.

Tightening the standards for soot pollution is a significant part of that effort, Alt said, noting that it is “essential to all Americans, to our health, to the health of the planet and to the U.S. role in the world when it comes to climate.”

Paul Billings, national senior vice president of public policy for the American Lung Association, said in an interview that the establishment of new standards at the federal level would set in motion a series of steps that would prompt states to identify communities that have excessive pollution levels.

States would then draft plans including a specific time frame—which, under federal guidelines, should not exceed nine years—for when they will achieve healthy air standards, Billings said.

At the same time, the standards would also drive EPA to propose more protective cleanup strategies and more rigorous rules for all pollution sources.

Billings noted that the general public may mistakenly believe that the particles do not pose a threat because they are so small. “Why should the public care?” he asked. “Because particulate matter, PM pollution, soot, whatever you want to call it, it kills people. And it kills tens of thousands of people every year.”

“These small particles get past the body’s natural defense mechanisms,” Billings said. “The big particles, they get caught in the nose, the mouth, you cough them out. The small particles get down deep and they get into the bloodstream and cause a wide range of adverse health effects. Coughing, wheezing. Shortness of breath. They’ve also been linked to lung cancer, heart attack, stroke and thousands and thousands of premature deaths in the United States every year.”

Raul Garcia, legislative director for healthy communities at the advocacy group Earthjustice, noted that the adverse effects of particulate matter pollution are not distributed evenly—people of color are 61 percent more likely to live in areas with unhealthy air quality. 

“This also means that they are more likely to suffer from diseases and conditions like asthma and other very harsh respiratory conditions,” Garcia said during a virtual news conference Tuesday about the Climate Action Campaign letter. “And so we have to have urgency.”

Garfield Clunie, president of the National Medical Association—the nation’s oldest group for Black physicians—said during the news conference that the benefits of a tougher soot pollution standard are “critically important to addressing health equity in this country, not just for people of color, but for everyone.”

Garcia noted that federal officials had been expected to rule as early as Monday—roughly three months after the Environmental Protection Agency forwarded a proposed updated pollution standard to the Office of Management and Budget. He urged officials to move quickly to enact the proposal.

The management and budget office typically does not comment on pending policy reviews. The EPA decided to reexamine the standard after the Trump administration declined to raise the standard in 2020.

“We really have to look at this as a critical public health and environmental justice issue,” Garcia said. “This isn’t rulemaking that simply sits on a piece of paper. This is something that’s going to have real world impacts to everyone’s lives, but particularly those communities who have had to bear the burden of energy consumption across the country. It’s important that these standards be lowered to an adequate level because we know that the current standards do not protect human health to the level that they should.”

“We need this rule to come out today,” Garcia said, “and we need this rule to be a set of strong standards so that communities can actually live and breathe air that isn’t going to kill them.”