"The Clean Air Act is a law with a 40-year track record of cutting dangerous pollution to protect human health and the environment. Administered by the Environmental Protection Agency (EPA), this legislation has prevented more than 400,000 premature deaths and hundreds of millions of cases of respiratory and cardiovascular disease."
Evolution of the Clean Air Act Requirements
U.S. Environmental Protection Agency
January 29, 2010
This chart, provided by the Environmental Protection Agency, shows the original requirements of the Clean Air Act and how they have changed over the years.