Air Quality
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Statewide PM 2.5 Measures

Percentage of population living in counties with PM2.5 levels greater than the annual standard (12 ug/m3), less than the annual standard, and with no monitor, California, 2000-2012

Year Number of counties with monitors Number of counties without monitors Percentage of population living in a county greater than the standard Percentage of population living in a county less than the standard Percentage of population living in a county with no monitor
2012 47 11 66.52 33.48 1.18
2011 48 10 76.62 23.38 1.16
2010 48 10 65.22 34.78 1.17
2009 45 13 78.68 21.32 1.79
2008 45 13 85.04 14.96 1.79
2007 44 14 79.16 20.84 1.92
2006 43 15 78.12 21.88 2.30
2005 44 14 78.45 21.55 2.25
2004 44 14 78.77 21.23 1.89
2003 44 14 71.31 28.69 1.93
2002 43 15 87.40 12.60 1.97
2001 43 15 86.06 13.94 1.98
2000 43 15 77.60 20.42 1.98


Notes

  • Data Source: California Air Resources Board
  • California has a total of 58 counties
  • The "Standard" refers to the U.S. EPA National Ambient Air Quality Standard for PM2.5. Attainment of the standard is calculated on an annualized basis.
  • PM2.5 (particulate matter with a diameter of less than 2.5 microns) is a Criteria Air Pollutant commonly found in diesal exhaust.
  • Exposure to PM25 has been associated with asthma attacks and reduces lung function.
  • This measure examines California's progress toward meeting the U.S. standard for all residents.