Contact EPA Pacific Southwest Air Program
Pacific Southwest, Region 9
Serving: Arizona, California, Hawaii, Nevada, Pacific Islands, Tribal Nations
Air Quality Analysis
Air Quality Trends
8-Hour Ozone (O3)
24-Hour Fine Particulate Matter (PM2.5)
Air Quality Trends (1975-2011)
8-Hour Ozone Concentrations
"Design Value" - National 8-hour Standard
Average of 4th Highest Days over Three Years
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