The top metropolitan areas for clean air.
- Cheyenne, Wyo.
- Santa Fe-Espanola, N.M.
- Honolulu
- Great Falls, Mont.
- Farmington, N.M.
- Flagstaff, Ariz.
- Tucson, Ariz.
- Anchorage, Alaska
- Bismarck, N.D.
- Albuquerque, N.M.
And dirty.
- Los Angeles-Long Beach-Riverside, Calif.
- Pittsburgh-New Castle, Pa.
- Bakersfield, Calif.
- Birmingham-Hoover-Cullman, Ala.
- Detroit-Warren-Flint, Mich.
- Cleveland-Akron-Elyria, Ohio
- Visalia-Porterville, Calif.
- Cincinnati-Middletown-Wilmington, Ohio-Ken.-Ind.
- Indianapolis-Anderson-Columbus, Ind.
- St. Louis-St. Charles-Farmington, Mo.-Ill.
Source: American Lung Association via WebMD