Depending on the country, there are different laws in effect to control air pollution. Assuming we are speaking about the United States, then the Clean Air Act of 1970 was a very important law. It was designed to control and prevent air pollution and regulate air emissions. The Environmental Protection Agency is responsible for enforcing this law. Ever since the Industrial Revolution, air pollution has become an important problem. The Clean Air Act relates to airborne contaminants, as well as smog and air pollution. In 1990, the Clean Air Act Amendments proposed emissions trading which provides economic incentives for companies to reduce emissions. It addressed ozone depletion, acid rain and new auto gasoline laws to control emissions from gasoline as well as have new formulas that cut down on pollutants.