America's cleanest and dirtiest cities

American Lung Association's list of cleanest cities when measured by all three criteria -- ozone, short-term particulates and long-term particulates. The Cleanest Cities in the U.S.
1. Fargo-Wahpeton, ND-MN
2. Billings, MT
3. Bismarck, ND
4. Cheyenne, WY
5. Colorado Springs, CO
6. Farmington, NM
7. Ft. Collins, CO
8. Honolulu, HI
9. Lincoln, NE
10. Midland-Odessa, TX
11. Port St. Lucie, FL
12. Pueblo, CO
13. Redding, CA
14. Salinas, CA
15. San Luis Obispo, CA
16. Santa Fe-Espanola, NM
17. Sioux Falls, ND
18. Tucson, AZ

25 Cities With The Worst Air Pollution: Ozone (Smog)
1. Los Angeles/Long Beach/Rierside, Calif.
2. Bakersfield, Calif.
3. Visalia-Porterville, Calif.
4. Fresno/Madera, Calif.
5. Houston/Baytown/Huntsville, Texas
6. Sacramento, Calif./Arden-Arcade/Yuba City, Nevada
7. Dallas/Fort Worth, Texas.
8. Charlotte/Gastonia/Salisbury, N.C.
9. Phoenix/Mesa/Scottsdale, Ariz.
10. El Centro, Calif.
11. Hanford/Corcoran, Calif.
12. Las Vegas/Paradise/Pahrump, Nevada
13. Sand Diego/Carslbad/San Marcos, Calif.
14. Washington, D.C./Baltimore, Md./No. Virginia
15. Cincinnati, Ohio/Middletown, Ky./Wilmington, In.
16. Philadelphia, Pa./ Camden, N.J./ Vineland, De.
17. St. Louis, Mo. / St. Charles / Farmington, Il.
18. New York, N.Y. / Newark, N.J. / Bridgeport, Conn.
19. Knoxville/Sevierville/ La Follette, Tenn.
20. Birmingham/Hoover/Cullman, Ala.
21. Baton Rouge/ Pierre Part, La.
22. Kansas City, Mo./ Overland Park, Ks.
23. Atlanta, Ga. / Sandy Springs / Gainesville, Ala.
24. Merced, Calif.
25. Memphis, Tenn.