Background
The six criteria air contaminants were the first set of pollutants recognized by the United States Environmental Protection Agency as needing standards on a national level. The Clean Air Act requires the EPA to set US National Ambient Air Quality Standards (NAAQS) for the six CACs. The NAAQS are health based and the EPA sets two types of standards: primary and secondary. The primary standards are designed to protect the health of 'sensitive' populations such as asthmatics, children, and the elderly. The secondary standards are concerned with protecting the environment. They are designed to address visibility, damage to crops, vegetation, buildings, and animals.
Read more about this topic: Criteria Air Contaminants
Famous quotes containing the word background:
“In the true sense one’s native land, with its background of tradition, early impressions, reminiscences and other things dear to one, is not enough to make sensitive human beings feel at home.”
—Emma Goldman (1869–1940)
“Pilate with his question “What is truth?” is gladly trotted out these days as an advocate of Christ, so as to arouse the suspicion that everything known and knowable is an illusion and to erect the cross upon that gruesome background of the impossibility of knowledge.”
—Friedrich Nietzsche (1844–1900)
“I had many problems in my conduct of the office being contrasted with President Kennedy’s conduct in the office, with my manner of dealing with things and his manner, with my accent and his accent, with my background and his background. He was a great public hero, and anything I did that someone didn’t approve of, they would always feel that President Kennedy wouldn’t have done that.”
—Lyndon Baines Johnson (1908–1973)