America's 25 Most Ozone-Polluted Metropolitan Areas

Updated April 16, 2020 | Infoplease Staff

Each year the American Lung Association issues their "State of the Air" report. They track year-round and short-term particle pollution as well as the ozone pollution listed here. Though ozone pollution isn't the obvious, sooty kind of pollution, it can still be harmful to your health. Studies have shown that ozone pollution can worsen conditions such as bronchitis, asthma, emphysema, and cardiovascular disease.

Rank: City
#1: Los Angeles-Long Beach-Riverside, CA
#2: Visalia-Porterville-Hanford, CA
#3: Bakersfield, CA
#4: Fresno-Madera, CA
#5: Sacramento-Roseville, CA
#6: San Diego-Chula Vista-Carlsbad, CA
#7: Phoenix-Mesa, AZ
#8: San Jose-San-Francisco-Oakland, CA
#9: Houston-The Woodlands, TX
#10: New York-Newar, NY-NJ-CT-PA
#11: Redding-Red Bluff, CA
#12: Denver-Aurora, CO
#13: Las Vegas-Henderson, NV
#14: Salt Lake CIty-Provo-Orem, UT
#15: El Centro, CA
#16: Washington-Baltimore-Arlington, DC-MD-VA-WV-PA
#17: Dallas-Fort Worth, TX-OK
#18: Chicago-Naperville, IL-IN-WI
#19: Chico, CA
#20: Sheboygan, WI
#21: Philadelphia-Reading-Camden, PA-NJ-DE-MD
#22: El Paso-Las Cruces, TX-NM
#23: Hartford-East Hartford, CT
#24: Fort Collins, CO
#25: Atlanta-Athens-Clarke County-Sandy Springs, GA-AL
Source: State of the Air: 2014, American Lung Association.
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