Nearly half of all Americans are breathing unhealthy levels of air pollution, a dramatic increase driven by extreme heat and wildfires, according to the American Lung Association’s 2025 “State of the Air” report released Wednesday.
The report finds that 156 million people—25 million more than last year—now live in areas with failing grades for ozone or particle pollution. It’s a sobering uptick that comes as the U.S. Environmental Protection Agency (EPA), long responsible for monitoring and regulating air pollution, faces staffing and funding cuts.
“Air pollution is causing kids to have asthma attacks, making outdoor workers sick, and leading to low birth weights in babies,” said Harold Wimmer, president of the American Lung Association. “And the very agency tasked with fixing this is being undermined.”
Key Findings
Who Is Affected?
- 156 million (46%) live in a county with a failing grade for at least one pollutant
- 42.5 million live in areas failing all three measures
- People of color are 2x as likely to live in areas with failing grades
- Hispanic residents are nearly 3x more likely than white residents to live in areas with failing grades across the board
Pollution by Category
Particle Pollution (PM2.5)
Fine particulate matter—emitted from wildfires, diesel engines, coal plants, and wood-burning stoves—is considered especially dangerous, contributing to asthma, heart attacks, strokes, cancer, and premature death.
Short-Term Particle Pollution (Spikes)
More Americans than ever before—77.2 million people—lived in counties with unhealthy spikes in particle pollution, the highest figure in the report’s 26-year history. This includes data from summer 2023, when Canadian wildfire smoke blanketed much of the Midwest and Northeast.
Top 10 Cities – Short-Term Particle Pollution
- Bakersfield-Delano, CA
- Fairbanks-College, AK
- Eugene-Springfield, OR (tie)
- Visalia, CA (tie)
- Fresno-Hanford-Corcoran, CA
- Reno-Carson City-Gardnerville Ranchos, NV-CA
- Los Angeles-Long Beach, CA
- Yakima, WA
- Seattle-Tacoma, WA
- Sacramento-Roseville, CA
Year-Round Particle Pollution
An estimated 85 million people lived in counties failing the year-round pollution standard—just shy of last year’s record 90.7 million.
Top 10 Cities – Year-Round Particle Pollution
- Bakersfield-Delano, CA
- Visalia, CA
- Fresno-Hanford-Corcoran, CA
- Eugene-Springfield, OR
- Los Angeles-Long Beach, CA
- Detroit-Warren-Ann Arbor, MI (tie)
- San Jose-San Francisco-Oakland, CA (tie)
- Houston-Pasadena, TX
- Cleveland-Akron-Canton, OH
- Fairbanks-College, AK
Ozone Pollution
Also known as smog, ozone is linked to respiratory distress, asthma, and reduced lung function. Driven by climate change, ozone levels rose significantly this year.
More than 125 million people (37% of the population) lived in areas with unhealthy ozone levels—24.6 million more than in last year’s report.
Top 10 Cities – Ozone Pollution
- Los Angeles-Long Beach, CA
- Visalia, CA
- Bakersfield-Delano, CA
- Phoenix-Mesa, AZ
- Fresno-Hanford-Corcoran, CA
- Denver-Aurora-Greeley, CO
- Houston-Pasadena, TX
- San Diego-Chula Vista-Carlsbad, CA
- Salt Lake City-Provo-Orem, UT-ID
- Dallas-Fort Worth, TX-OK
Where the Air Is Clean
Just two cities made the list for clean air across all three categories, compared to five last year:
- Bangor, ME
- San Juan, PR
The Call to Action
Despite alarming figures, only 922 of the country’s 3,221 counties currently monitor air pollution, leaving more than 72.8 million people in unmonitored zones.
The Lung Association is urging Americans to defend the EPA, warning that budget cuts and staff reductions threaten efforts to maintain air quality protections.
“Without EPA programs,” Wimmer said, “families won’t know what’s in the air they’re breathing.”
See the full report and get involved at Lung.org/sota