Florida Not Among 20 Most Polluted Cities in America
Since pollution regulations started in the 1960s with the Clean Air Act, air quality in the United States has improved. That said, while many Americans can breathe easier thanks to air pollution laws, parts of the country are more polluted than others.
Some cities’ pollution comes from car usage along major highways, with wildfires and industrial businesses also accounting for a drop in air quality.
Using pollution data, Visual Capitalist ranked the most polluted cities in the U.S. You might already know you’re living in a city with poor air quality, judging by the hazy vistas in your area. In contrast, you might not expect to see some of the cities on this list.
Tracking Pollution Levels

Visual Capitalist gathered data from the American Lung Association’s 2024 State of the Air report to determine the most polluted cities in the United States. Statistics from the report showed a rise in deadly particle pollution, with 39% of Americans living in areas with unhealthy levels of air pollution.
Just because more Americans are living in areas with bad air pollution doesn’t necessarily mean pollution is getting worse, though. Air pollution levels increased, in part, due to new Environmental Protection Agency (EPA) standards. These new standards reflect updated findings on the health of Americans living in highly polluted areas.
Judging by the data, the cities on this most-polluted list are the most likely to have a negative impact on your health. Visual Capitalist ranked the cities based on PM2.5 concentrations, which stands for particulate matter 2.5. These tiny particles in the air can be detrimental to our health.
For reference when comparing the PM2.5 levels in the following cities, the American Lung Association believes PM2.5 levels shouldn’t exceed 9.0, while the World Health Organization believes it shouldn’t exceed 5.0.
1. Bakersfield, California

Annual PM2.5 concentrations: 18.8
2. Visalia, California

Annual PM2.5 concentrations: 18.4
3. Fresno, California

Annual PM2.5 concentrations: 17.5
4. Eugene, Oregon

Annual PM2.5 concentrations: 14.7
5. Bay Area, California

Annual PM2.5 concentrations: 14.3
6. Los Angeles, California

Annual PM2.5 concentrations: 14.0
7. Sacramento, California

Annual PM2.5 concentrations: 13.8
8. Medford, Oregon

Annual PM2.5 concentrations: 13.5
9. Phoenix, Arizona

Annual PM2.5 concentrations: 12.4
10. Fairbanks, Arkansas

Annual PM2.5 concentrations: 12.2
11. Indianapolis, Indiana

Annual PM2.5 concentrations: 11.9
12. Yakima, Washington

Annual PM2.5 concentrations: 11.8
13. Detroit, Michigan

Annual PM2.5 concentrations: 11.7
14. Chico, California

Annual PM2.5 concentrations: 11.6
15. Spokane, Washington

Annual PM2.5 concentrations: 11.6
Note: Spokane ties with Chico.
16. El Centro, California

Annual PM2.5 concentrations: 11.1
17. Reno, Nevada

Annual PM2.5 concentrations: 11.0
18. Pittsburgh, Pennsylvania

Annual PM2.5 concentrations: 10.9
19. Kansas City, Kansas

Annual PM2.5 concentrations: 10.8
20. Las Vegas, Nevada

Annual PM2.5 concentrations: 10.8
Note: Las Vegas ties with Kansas City.
San Joaquin Valley’s Impact

Based on Visual Capitalist’s data, California is the most polluted state in America, with six cities ranking in the top ten. The most polluted city on the list, Bakersfield, is located in California’s San Joaquin Valley, home to major warehouse distribution and oil and agriculture production. That part of the state hasn’t complied with the EPA for about 25 years.
As of 2022, the EPA extended deadlines for California to meet air pollution standards, threatening to sanction infrastructure funding. Because nothing has been done, environmental groups sued the EPA to take faster action to improve the area’s air quality.
Wildfires and Air Pollution

Two cities in Oregon rank in the top ten of the most polluted cities, Eugene and Medford. Wildfires in the region are the leading cause of the smoky, poor air quality. The poor air conditions in the Beaver State have increased recently because of a rise in hot and dry conditions.
While Oregon has some of the most polluted cities in the U.S., its air quality has improved since the 1970s. Efforts to decrease emissions from over 150 industries have helped Oregon’s largest city, Portland, avoid ozone and carbon monoxide violations for decades.
Improving Air Quality

While legislative change can reduce air pollution, Americans can also take personal action to help improve air quality. Experts say that using wood stoves less frequently during the winter will promote cleaner air.
Some of the other best ways to improve air quality are to drive less by planning better, using public transportation, and working from home. Other things that can help the environment are refueling cars during the cooler evening, cutting out spray pesticides, and turning on gas-powered garden equipment later in the day.