Ground-level Ozone Basics (US EPA)
Ozone in the air we breathe can harm our health, especially on hot sunny days when ozone can reach unhealthy levels.
Hazardous air pollutants (US EPA)
Information about the 187 hazardous air pollutants (HAPs), also known as air toxics.
Urban air toxics information (US EPA)
Information about the 30 HAPs of greatest threat to public health in urban areas, also know as urban air toxics.
Identified Toxic Air Contaminants (CARB)
California-specific information on toxic air contaminants/air toxics.