Outdoor Air Quality Standards
Ambient air quality standards (AAQS) set air pollutant levels that can be present outdoors without harming the public's health.
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Public Health & the Environment
A number of air pollutants, emitted from a variety of sources, impact the health of Californians everyday. U.S. EPA sets National Ambient Air Quality Standards (NAAQS) for six pollutants, including ozone and particulate matter. ARB sets California Ambient Air Quality Standards (CAAQS) for the same six pollutants, as well as for four additional pollutants. ARB also identifies other air pollutants as toxic air contaminants (TACs) - pollutants that may cause serious, long-term effects, such as cancer, even at low levels.