Nearly Half of U.S. Population Breathes Unhealthy Air, American Lung Association Warns

In its latest State of the Air report for 2025, the American Lung Association (ALA) is warning that nearly half of all Americans are breathing in unhealthy levels of air pollution.

One of the biggest takeaways of this year’s report is that 156.1 million people, or about 46% of the U.S. population, live in areas with unhealthy ozone or particle pollution levels. That means about 25 million more people are exposed to these pollutants compared to the previous report.

Some of the biggest factors behind the increase include worsening droughts, heat waves and wildfires, according to the ALA.

“Families across the U.S. are dealing with the health impacts of air pollution every day, and extreme heat and wildfires are making it worse,” Harold Wimmer, president and CEO of the ALA, said in a press release. “Air pollution is causing kids to have asthma attacks, making people who work outdoors sick, and leading to low birth weight in babies. This year’s report shows the dramatic impact that air pollution has on a growing number of people.”

Based on the findings, people of color are experiencing the greatest burden from high levels of air pollution. Of the total number of people living in a county with at least one failing grade for air pollutant levels, people of color make up 50.2%, despite people of color comprising 41.2% of the total U.S. population. According to the findings, Hispanic individuals are about three times more likely to live in a community with at least three failing grades compared to white individuals.

The report also listed the nation’s most- and least-polluted cities. Bakersfield-Delano, California led in both the categories of highest short-term ozone and year-round fine particulate matter pollutants (PM2.5), while Los Angeles-Long Beach, California topped the list for highest ozone pollution.

Only two cities this year (compared to five last year), achieved the highest possible marks for all three metrics — Bangor, Maine and San Juan, Puerto Rico.

In a separate study released this week, researchers from Pennsylvania State University’s (Penn State) College of Health and Human Development found that more than 50 million people in the U.S. live in counties that lack air quality monitoring sites. This could mean that millions more people are exposed to air pollution without knowing it, leaving people vulnerable to the effects of poor air quality.

“Air pollution affects everyone’s health, so it is important for everyone in the nation to have access to accurate information about the quality of the air they breathe,” Nelson Roque, lead author of the Penn State study, said in a statement. “Where we don’t collect data, the threat and impact of pollution are invisible.”

Yet while millions of people in the U.S. lack active air quality monitoring services and even more Americans are exposed to air pollution, the current administration could further threaten public and environmental health with massive cuts to the Environmental Protection Agency (EPA), Inside Climate News reported. 

In response, the latest report from the American Lung Association included calls for public support of the EPA and the agency’s enforcement of the Clean Air Act.

“The EPA is a necessity,” said Dr. Afif El-Hasan, a pediatrician in Southern California and a member of ALA’s board of directors, as reported by Inside Climate News. “It is actually part of the health care system and should be treated accordingly.”

The ALA is urging Americans to contact their representatives to take action against EPA staff cuts and has created an email form for convenient submissions.

“Even as more people are breathing unhealthy air, the federal staff, programs and policies that are supposed to be cleaning up pollution are facing rollbacks, restructuring and funding challenges,” Wimmer said. “For decades, the U.S. Environmental Protection Agency (EPA) has worked to ensure people have clean air to breathe, from providing trustworthy air quality forecasts to making sure polluters who violate the law clean up. Efforts to slash staff, funding and programs at EPA are leaving families even more vulnerable to harmful air pollution. We need to protect EPA.”