New report ranks the most polluted places in the U.S.

File: The One World Trade Center and the New York skyline is seen in the background as a man jogs through the Liberty State Park while the smoke from Canada wildfires covers the Manhattan borough on June 8, 2023 in New Jersey. (Photo by Eduardo Munoz

In its 25th annual look at pollution around the U.S., the American Lung Association says 131.2 million people – that’s 39% of Americans – live in communities with failing grades for unhealthy levels of ozone or particle pollution. 

Their "State of the Air" 2024 report says that number is up by 11.7 million people compared to last year. The association blames extreme heat, drought and wildfires for the particle pollution – especially in the western U.S. – but also cites a new "more protective" national air quality standard from the EPA.

"When we started doing ‘State of the Air’ in 2000, I never imagined that in the 25th edition we would be reporting that more than 100 million people are still breathing unhealthy air. It’s unacceptable," said Paul Billings, the American Lung Association’s national senior vice president for public policy.

Map: Most polluted places

The vast majority of the cities and counties flagged in the report are out west; many in California. And the ALA noted a racial disparity as well. 

"Although people of color make up 41.6% of the overall population of the U.S., they are 52% of the people living in a county with at least one failing grade," the report states. "In the counties with the worst air quality that get failing grades for all three measures of air pollution, 63% of the nearly 44 million residents are people of color, compared to 37% who are white."

LINK: Read the full report

The report looks at two of the most widespread and dangerous air pollutants: Fine particles and ozone.

Ozone pollution

Ozone pollution is a respiratory irritant whose effects have been likened to "sunburn of the lungs," the report explained. Breathing ground-level ozone can cause shortness of breath, coughing and asthma attacks and may even shorten life. 

The ALA says warmer temperatures driven by climate change make ozone more likely to form and harder to clean up.

Cities most polluted by ozone:

  1. Los Angeles-Long Beach, CA
  2. Visalia, CA
  3. Bakersfield, CA
  4. Fresno-Madera-Hanford, CA
  5. Phoenix-Mesa, AZ

Particle pollution

Tiny particles in the air – some smaller than 1/30th the diameter of a human hair – are small enough to get past the body's natural defenses when inhaled.

These particles come from a variety of sources including wildfires, wood-burning stoves, coal-fired power plants, and diesel engines and can trigger asthma attacks, heart attacks and strokes, and cause lung cancer.

RELATED: Air pollution from wildfires linked to dementia cases, study says

The report has two grades for particle pollution: one for "short-term" particle pollution, or daily spikes like those from last year's wildfires, and one for the annual average "year-round" level that represents the concentration of particles in each location.

Worst short-term particle pollution:

  1. Bakersfield, CA
  2. Fresno-Madera-Hanford, CA
  3. Fairbanks, AK
  4. Eugene-Springfield, OR
  5. Visalia, CA

Worst year-round particle pollution:

  1. Bakersfield, CA
  2. Visalia, CA
  3. Fresno-Madera-Hanford, CA
  4. Eugene-Springfield, OR
  5. San Jose-San Francisco-Oakland, CA

What are the cleanest places to live?

It’s not all bad news. Five places made the cleanest cities lists for particle pollution and ozone.

Listed alphabetically, the cleanest cities are:

  • Bangor, Maine
  • Honolulu, Hawaii
  • Johnson City-Kingsport-Bristol, Tennessee/Virginia
  • Lincoln-Beatrice, Nebraska
  • Wilmington, North Carolina