2008 PM2.5 Air Quality Table Table 2-17 Page 2-29 AIR BASIN 2006 Maximum 24-Hr Concentration in micrograms/cubic meter 98th Percentile 24-Hr Conc. (ug/m3)** 2006 Average of Quarterly Means in micrograms/cubic meter** State National State National Great Basin Valleys 193.0 193.0 Lake County 21.6 21.6 21.4 5.1 5.1 Lake Tahoe Mojave Desert 22.0 22.0 19.0 10.3 10.4 Mountain Counties 62.7 51.0 31.0 8.6 10.9 North Central Coast 13.0 13.0 North Coast 35.0 35.0 17.4 6.8 6.8 Northeast Plateau 22.0 22.0 Sacramento Valley 78.6 78.0 59.0 15.2 13.2 Salton Sea 80.8 68.8 46.0 17.3 12.5 San Diego 63.3 63.3 28.4 13.1 13.1 San Francisco Bay Area 75.3 75.3 42.8 12.4 9.3 San Joaquin Valley 88.1 87.0 64.7 21.6 19.3 South Central Coast 119.5 31.7 27.6 10.3 10.3 South Coast 72.2 72.2 54.4 16.6 20.8