the Clean Air Act amendments in 1967 (also called the Air Quality Control Act) required the setting of national emission standards for pollutants. These emission standards were applied across the country to all stationary sources and recommended some control technologies.
These latter two points are noteworthy since they required the EPA to significantly reduce day-to-day "routine" emissions of those air pollutants known or suspected to cause serious health problems. The 1990 act also further strengthened the National Ambient Air Quality Standards for the "criteria" pollutants established in 1970 particularly regarding the ozone precursors, NOx and Volatile Organic Compounds.
During the 20 years preceding 1990, the EPA was only able to implement
These latter two points are noteworthy since they required the EPA to significantly reduce day-to-day "routine" emissions of those air pollutants known or suspected to cause serious health problems. The 1990 act also further strengthened the National Ambient Air Quality Standards for the "criteria" pollutants established in 1970 particularly regarding the ozone precursors, NOx and Volatile Organic Compounds.
During the 20 years preceding 1990, the EPA was only able to implement