Most Polluted US Cities

Unhealthy air remains a threat to the lives and health of millions of people in the United States, despite great progress. Air pollution lingers as a widespread and dangerous reality even as some seek to weaken the Clean Air Act, the public health law that has driven the cuts in pollution since 1970. The State of the Air 2011 Report by the American Lung Association shows that air quality in many places in the US has improved but that over 154 million Americans, just over one half of the nation, still suffer pollution levels that are often dangerous to breathe.

bakersfield ca pollution most polluted US cities

Bakersfield, CA, is, according to the American Lung Association, the most polluted US city...

According to the report four of the most polluted US cities are located in California, with Bakersfield being described as the dirtest city in the US. The American Lung Association named Cheyenne, Wyoming, as the cleanest city in America. The report looked at levels of ozone and particle pollution found in official monitoring sites across the United States in 2007, 2008, and 2009.

Overall findings:
• Roughly half the people (50.3%) in the United States live in counties that have unhealthful levels of either ozone or particle pollution. Almost 154.5 million Americans live in the 366 counties where they are exposed to unhealthful levels of air pollution in the form of either ozone or short-term or year-round levels of particles.

• Roughly one in 17 people – more than 18.5 million in the United States – live in 10 counties with unhealthful levels of all three measures covered in the report: ozone and short-term and year-round particle pollution.

• The strongest improvement came in reducing ozone smog levels across the nation. More than half of the country’s most-smog-polluted cities experienced their best year yet. All metro areas in the 25 cities most-polluted by ozone showed improvement over last year’s report. Still nearly half the people in the US (48.2%) live in areas with unhealthful levels of ozone pollution.

• All but two of the 25 cities most polluted by year-round levels of particle pollution (sometimes called soot) improved over last year’s report. Nineteen of those cities reported their best-ever particle pollution levels.

• Success in reducing short-term particle pollution levels varied among metro areas. Twelve of the most polluted cities saw improvement compared to last year’s report, while 17 had worse problems with these spikes in particle levels.

The most polluted US cities
(By particle pollution)
1 Bakersfield, CA
2 Los Angeles, CA
2 Phoenix, AZ
2 Visalia, CA
5 Hanford, CA
6 Fresno, CA
7 Pittsburgh, PA
8 Birmingham, AL
9 Cincinnati, OH
10 Louisville, KY
10 Modesto, CA
12 Charleston, WV
12 Cleveland, OH
12 Steubenville, OH
15 Huntington, WV
15 Indianapolis, IN
17 Detroit, MI
17 Houston, TX
17 St. Louis, MO
20 Hagerstown, MD
21 New York City, NY
22 Dayton, OH
22 Lancaster, PA
24 Knoxville, TN
24 Parkersburg, WV
24 Philadelphia, PA
24 York, PA

The 25 cleanest US cities
(By particle pollution)
1 Cheyenne, WY
2 Santa Fea, NM
3 Tucson, AZ
4 Great Falls, MT
4 Honolulu, HI
6 Anchorage, AK
7 Albuquerque, NM
7 Amarillo, TX
9 Redding, CA
10 Salinas, CA
11 Bismarck, ND
12 Boise City, ID
13 Billings, MT
14 Cape Coral, FL
14 Flagstaff, AZ
14 Fort Collins, CO
14 Palm Bay, FL
14 Sarasota, FL
19 Claremont, NH
20 Port St. Lucie, FL
20 Rapid City, SD
22 Duluth, MN
23 Fargo, ND
24 Bangor, ME
24 Burlington, VT
24 Orlando, FL

Over 2,000 Dangerous ‘Bad Air’ Days Logged in First Seven Months of 2011

In Pictures: America’s 10 Most Toxic Cities

Search Site

Loading