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When Cynthia Pinto-Cabrera developed asthma at age 12, it didn't seem so unusual to her. Many of his classmates in California's San Joaquin Valley carried inhalers to school. His little brother needed a nebulizer every morning to start the day off right by breathing.
But when she left the Valley to attend college in Santa Barbara, Pinto-Cabrera discovered a world with far less air pollution than the one in which she had lived. She found it shocking that other parts of the country were simply living with cleaner air – and their health benefiting as a result.
“A lot of people here in the Valley don’t really know that asthma isn’t normal,” she says. “We’ve really normalized chronic illness.”
Pinto-Cabrera is one of many people across the country celebrating a Wednesday announcement from the U.S. Environmental Protection Agency, which unveiled new, tougher limits for one of the deadliest types of air pollution : tiny particles about 30 times smaller than a human hair. These particles are called PM2.5 (short for particles less than 2.5 micrometers in diameter) and are commonly referred to as soot.
The agency lowered the allowable limit for annual PM2.5 levels from 12 micrograms per cubic meter to 9. This is a “significant reduction,” says Regan Patterson, an air pollution expert at the University of California to Los Angeles.
“The science is clear,” says EPA Administrator Michal Regan. “Soot pollution is one of the most dangerous forms of air pollution and is linked to a range of serious and life-threatening illnesses, including asthma and heart attacks.”
The new standard represents the first tightening of the rules since 2012, but states will have several years to reach the new limits.
The EPA left daily PM2.5 pollution limits unchanged, at 35 micrograms per cubic meter, saying the same efforts that will reduce pollution under the revised annual standard will also reduce pollution exposures in the short term.
Decades of research have shown that tiny particles are hazardous to health, regardless of their concentration. Sources vary: fossil fuel burning, agriculture and industrial processes all add to the load, as does smoke and dust from wildfires.
Overall, the tiny particles conduct millions of premature deaths around the world every year. The EPA estimates that the new, stricter standards will prevent about 4,500 premature deaths per year by 2032 in the United States and prevent about 800,000 asthma-related emergency room visits. It estimates that less exposure to pollution could reduce health care costs by about $46 billion by then.
If met, these standards would have major impacts on communities that currently breathe the dirtiest air, such as the San Joaquin Valley in California's Pinto-Cabrera or the industrial counties of central Pennsylvania. “What we find in study after study is that people of color are consistently breathing the dirtiest air,” Patterson says.
A 2022 study, for example, found that communities of color were constantly exposed to more air pollution than white communities. Another analysis shows they are exposed to more pollution than the national average from each sourcefrom industrial production to agricultural pollution.
The new standards will not erase these differences. But the EPA's analysis suggests the new rules should reduce them. “It's important to step back and recognize that by lowering standards, when you improve air quality through those standards, you get reductions that improve air quality for everyone,” explains Patterson. But cleaner air will have the greatest health impacts in communities that currently experience the worst pollution. “These are the communities for whom the standard will provide the most benefit,” Patterson says.
The new standards remain well above the World Health Organization's recommended limit of 5 micrograms per cubic meter on average over the year.
Uneven progress on clean air
Air quality in the United States has improved significantly since the Clean Air Act of 1970 began to reduce outdoor air pollution.
“There was a time when in big cities in this country you couldn't see across the street, the air was so thick,” says Paul Billings, president of the American Lung Association. “Thanks to the Clean Air Act and more than 50 years of progress, we have, as a nation, significantly cleaned our air.”
The EPA is supposed to review new science and update standards every five years to protect public health. The annual PM2.5 limit was first implemented in 1997 and was tightened in 2012 15 to 12 micrograms per cubic meter of air.
In 2020, under the Trump administration, the EPA decided to maintain current standards rather than strengthen them. The decision was controversial: longtime EPA scientists recommended stricter standards, while an advisory committee made up of several industry representatives opposed it. In 2021, under the Biden administration, the EPA decided to re-evaluate this decision. The new standards are the result of this review.
Public health experts say these updates are necessary because fine particle pollution and its deadly effects are far from gone. Researchers estimate that PM2.5 pollution kills up to 100,000 people across the country every year, making it, by some measures, the the most serious risk to public health in the United States today.
The dangers of soot
The tiny particles are dangerous because they can penetrate deep into people's lungs and pass into the bloodstream, causing inflammation and other chronic problems. Long-term exposure leads to increased risks, including heart attacks, strokes, dementia, hypertension and chronic kidney disease. Health risks arise from lower annual exposure levels even the new standard of 9 micrograms per cubic meter per year.
“These small particles, when they enter the lungs and bloodstream, have a devastating impact on human health” in every way possible, says Doris Browne, former president of the National Medical Association.
Fifteen counties out of more than 3,000 in the country fail to meet meet current EPA standards. Current violators are concentrated in California, Ohio and Pennsylvania, places with significant industrial activity, fossil fuel burning and agriculture.
Chris Chavez leads the policy efforts of the California Clean Air Coalition and grew up with asthma in one of the counties where the air does not meet current EPA standards. “While it’s great to have new standards, the challenge remains to meet the old ones,” he says.
Many of the places with the dirtiest air are home to communities of color. This division is not accidental: Racist zoning and planning practices that have persisted for decades and, in some cases, continue today, often concentrate sources of pollution near black, brown, and poor communities . Today, wealthy and middle-class Black Americans breathe more polluted air than white Americans. in all income brackets.
“We know that this impact is greatest on African Americans and other underserved people of color,” Browne says. Cleaner air, she said, would also benefit these communities the most.
The EPA estimates that PM2.5 levels in 119 counties are currently at levels that would not meet the new standards.
Several large industrial groups oppose the new standards. The American Forest and Paper Association suggests that stricter limits will restrict commercial activity, limiting the development of new facilities and even improving the efficiency of current facilities. The new standards, they say, are too close to current average pollution levels nationally.
“This rule threatens plans to modernize manufacturing sectors across our country,” says Paul Noe, vice president of the American Forest and Paper Association.
The stricter annual standards “will provide real, real public health benefits,” says Julie McNamara, a policy expert at the Union of Concerned Scientists. They also fail in some ways, she says.
Even though the allowable annual exposure level has been lowered, the allowable daily standard has not – and many pollution sources emit inconsistently or over short periods of time. So “there’s also room to continue to grow,” McNamara says. The EPA said the tougher annual standards should also reduce soot pollution in the short term.
Any progress is helpful, Pinto-Cabrera says. She's 26 now and lives in the San Joaquin Valley, near where she grew up. “So many kids, it ends up shaping their lives, their relationship to physical activity,” she says. “I was born here, I grew up here. I want to see my health improve and I want my children to grow up here healthy.”