Nearly half of Americans live in an area with a failing grade for air pollution, and the problem is only getting worse

Air pollution levels keep getting worse for more people in the US, according to a new report, and experts say the Trump administration’s proposed deregulation plans will make it even harder for people to get clean air.

Almost half of everyone who lives in the United States breathes unhealthy levels of air pollution, according to the American Lung Association’s annual State of the Air report, released Wednesday.

According to air quality data from 2021 to 2023, about 156 million people – 25 million more than last year’s report – live in an area that the association gives a failing grade for ozone and two measures of fine particulate matter pollution.

The US Environmental Protection Agency defines particulate matter, also called particle pollution or soot, as a mix of solid and liquid droplets that float in the air. It can come in the form of dirt, dust or smoke. Coal- and natural gas-fired power plants create it, as do cars, agriculture, unpaved roads, construction sites and wildfires.

Particle pollution threatens human health because it is so tiny – a fraction of the width of a human hair – and can travel past the body’s usual defenses. When a person breathes these particles in, they can get stuck in the lungs and move into the bloodstream, causing irritation and inflammation.

Exposure to particle pollution is considered a significant factor in premature death around the world, according to the World Health Organization. Exposure can also raise the risk of conditions including certain cancers, stroke, asthma, preterm births, dementia, depression and anxiety.

The new report says that 85 million people in the US live in an area with a failing grade for year-round particle pollution, the second-highest number of people with such exposure since the report was first published in 2000.

The top 10 areas most polluted by year-round particle pollution are:

Even in the short term, exposure to particle pollution can cause breathing problems or trigger a heart attack.

During the research period, the report says, short-term particle pollution in the US was the highest level it has been in 16 years, with 77.2 million people living in counties with these unhealthy spikes.

The 10 areas most polluted by short-term particle pollution are:

Ozone pollution, also called smog, is the presence of ground-level ozone that forms when chemicals like nitrogen oxides and volatile organics from electric utilities, car exhaust, gasoline vapors, industrial facilities and chemical solvents react to sunlight.

Exposure to ozone pollution can cause asthma attacks and chest pain in the short term. Long-term exposure can also cause decreased lung function and premature death.

The top 10 areas most polluted by ozone are:

The American Lung Association report notes that people of color are the group most likely to live in neighborhoods with unhealthy air and are more than twice as likely as White people to live a community with a failing grade for two types of particle pollution or ozone pollution.

People who identify as Hispanic are three times more likely as White people to live in an area with three failing grades for air pollution.

Dr. Juanita Mora, a pulmonologist who works in a predominantly Hispanic neighborhood on Chicago’s South Side, said she sees the toll of high air pollution levels nearly every day.

The demolition of a power plant in the area in 2020 spread soot “for miles and miles,” she said. When that combined with normal pollution levels, street vendors, other outdoor workers and a 7-year-old boy all came in wheezing and coughing.

“He was just outside playing in his yard,” said Mora, who is also a volunteer spokesperson for the American Lung Association. “His parents had to rush him to the ER because he said he was having chest tightness and couldn’t stop coughing.

“As a doctor, I feel like we’re failing millions and millions of kids and adults,” she added.

It doesn’t always take a demolished building for air pollution to cause widespread breathing problems.

Katherine Pruitt, national senior director for policy at the American Lung Association and a co-author of the new report, said that a record number of warm days and wildfires during the research period caused “horrible ozone years.”

People didn’t even have to live close to a wildfire to be affected, Pruitt said. Smoke plumes travel, and when they combine with typical pollution in urban areas, “they bump up the ability to produce ozone-forming compounds,” Pruitt said.

In 2023, Canadian wildfires caused problems for Mora’s patients hundreds of miles away in Chicago. “I saw so many kids and adults with asthma exacerbations around that time,” she said.

Dr. Panagis Gallatsatos, a pulmonary and critical care medicine specialist at Johns Hopkins Medicine, said doctors do what they can to help patients breathe better, “but we can only do so much against the air that they breathe.”

Gallatsatos, who is also a volunteer spokesperson for the Lung Association, said it’s been “rather defeating” to read about how many more Americans have been exposed to pollution.

“As a lung doctor, I don’t have any medication that can really offset that,” he said. “For pollution, we rely on good policies and legislation to protect lung health.”

And protective legislation may become harder to find. As part of the “biggest deregulatory action in US history,” the EPA said last month that it will revisit the Biden-era National Ambient Air Quality Standards for Particulate Matter, which govern how much soot can be released into the air.

The Trump administration is also considering looser regulations on power plants, the oil and gas industry, coal plants and other industries and machines that generate air pollution.

“Obviously, we’re worried about what the future portends for all the hard work that we’ve done to put rules and practices into place to control emissions, both for particle pollution and ozone and for greenhouse gases that are affecting the climate,” Pruitt said. “It’s very worrisome.”

If EPA deregulation efforts are successful, Mora said, it will directly hurt her patients who are already breathing polluted air.

“I believe I’m going to be seeing a lot more kids, more families affected by the lack of limits on particle pollution as well as ozone pollution, especially here in the city of Chicago,” she said. “If you can’t breathe, nothing else matters.”