The most common air pollutants are called criteria pollutants and are regulated by the Clean Air Act and the EPA. These pollutants are: particles, ozone, nitrogen oxides, sulfer dioxide, carbon monoxide, and lead. The EPA have sections under the CAA that help regulate factories and air pollution in the environment. For example section 108 requires the EPA to identify the pollutants that are criteria pollutants, listed above, and determine if where they are coming from and if they "endander public health or welfare". Under section 109 the EPA had to set standards across the board for air pulltion in regard to human health and to the environemtn sperately (Christopher D. Ahlers 2016, 51-52). There are many more sections that go into detail about what the CAA can do and what the EPA members are required to do as well.
