Clean Air Act
The Clean Air Act (CAA) was passed by Congress in 1970. The act was then revised in 1977 and again in 1990. The Clean Air Act was created to clean up the smog that polluted many cities in the United States. The CAA authorizes the U.S. Environmental Protection Agency to create national standards to limit the amount of certain pollutants including ozone, lead, carbon monoxide, sulfur dioxide and particulate matter.