<Tr> <Th_colspan="2"> United States Supreme Court cases </Th> </Tr> <Tr> <Td_colspan="2"> Union Elec . Co. v. EPA, 427 U.S. 246 (1976) Chevron USA v. Natural Resources Defense Council, 467 U.S. 837 (1984) Whitman v. American Trucking Ass'ns, Inc., 531 U.S. 457 (2001) </Td> </Tr> <P> The Clean Air Act is a United States federal law designed to control air pollution on a national level . It is one of the United States' first and most influential modern environmental laws, and one of the most comprehensive air quality laws in the world . As with many other major U.S. federal environmental statutes, it is administered by the U.S. Environmental Protection Agency (EPA), in coordination with state, local, and tribal governments . Its implementing regulations are codified at 40 C.F.R. Subchapter C, Parts 50 - 97 . </P> <P> The 1955 Air Pollution Control Act was the first U.S federal legislation that pertained to air pollution; it also provided funds for federal government research of air pollution . The first federal legislation to actually pertain to "controlling" air pollution was the Clean Air Act of 1963 . The 1963 act accomplished this by establishing a federal program within the U.S. Public Health Service and authorizing research into techniques for monitoring and controlling air pollution . </P>

What is the meaning of clean air act