Arizona vs. California vs. Florida vs. New York vs. Nevada

By 2007 EPA data:

Pinal Arizona had 94 bad air days[2].

San Bernardino, California's worst part had 44 bad air quality days this year[1].

Hillsbourough and Duval, Florida had 4 and 3 bad air quality days respectively[1]. 

Harris, Texas had 3 bad air days, Galveston, TX had 2 bad air quality days[2].

Essex and Westchester, NY had 2 bad air quality days[1]. 

Clark and Nye, Nevada had 2 bad air quality days[2].

[1]http://www.epa.gov/cgi-bin/broker?condition=none&citycounty=state&geocode=06+36+12&statecode=06+36+12&_debug=2&_service=aircomp&_program=dataprog.wcj_bycompare_state.sas+&submit=Compare+My+Air

[2]http://www.epa.gov/cgi-bin/broker?condition=none&citycounty=state&geocode=32+04+48&statecode=32+04+48&_debug=2&_service=aircomp&_program=dataprog.wcj_bycompare_state.sas+&submit=Compare+My+Air