Protecting Clean Air
The Clean Air Act, which was last amended in 1990, requires EPA to set National Ambient Air Quality Standards (NAAQS - pronounced "nacks") for pollutants considered harmful to public health and the environment. The Clean Air Act identifies two types of standards for ambient (outdoor) air:
- A primary standard, designed to protect public health
- A secondary standard, designed to protect public welfare. Welfare includes damage to plants and animals, impairment of visibility, and property damage.