Five California Cities Improve Air Quality

Five of the top 10 metropolitan areas with the largest improvements in air quality over a 12-year period are located in California, according to the 10th Annual Index of Leading Environmental Indicators, reported by the Pacific Research Institute. The list is based on the Environmental Protection Agency's Air Quality Index (AQI), which rates air quality on a scale of one to 500. AQI readings above 100 identify unhealthy air quality in a specific region. The following California cities are among the top 10 U.S. cities with the largest reduction in the number of days with AQI readings above 100: Los Angeles-Long Beach, San Diego, Riverside-San Bernardino, Orange County and Sacramento. Air quality in these areas improved an average of 59 percent during 1992-2003 when compared with the previous decade.
Full Article: Index of Leading Environmental Indicators 2005