Air pollution continues to be an important public health concern. A number of air pollutants, coming out of a variety of industrial processes, impact the health of California residents. Air monitoring shows that over 90 percent of Californians breathe unhealthy levels of one or more air pollutants during some part of the year. The California Air Resources Board (CARB) establishes health-based ambient air quality standards to identify outdoor pollutant levels that are considered safe for the public - including those individuals most sensitive to the effects of air pollution, such as children and the elderly.
CARB has set standards for eight "traditional pollutants," such as ozone and particulate matter. In addition to setting standards, CARB identifies other air pollutants as toxic air contaminants (TACs) - pollutants that may cause serious, long-term effects, such as cancer, even at low levels. Most air toxics have no known safe levels, and some may accumulate in the body from repeated exposures. CARB has identified about 200 pollutants as air toxics, and measures continue to be adopted to reduce emissions of air toxics. Estimated total cancer risk from all air toxics is 730 per million. Of this total, 520 per million are due to diesel particulate matter.
If PM2.5 were reduced to background levels, estimated health impacts avoided per year would be:
7,200 premature deaths
5,200 emergency room visits
Similarly, if diesel particulate matter were removed from the air, estimated yearly health impacts would be:
1,400 premature deaths
600 emergency room visits
Both traditional pollutants and toxic air contaminants are measured statewide to assess programs for cleaning the air. CARB works with local air pollution control districts to reduce air pollution from all sources.
Climate change will also pose risks to public health. Changes in our climate are leading to extreme high temperatures which could result in more heat-related sickness and deaths, increased allergens (such as pollen) will trigger worsened allergies, and increases in disease-carrying mosquitoes and other pests will cause elevated disease risk.