ere. Winds mix them in the troposphere and evenly distributes the gases. After a period of several years, CFC and ODS molecules reach the stratosphere and are broken by the ultraviolet rays releasing chlorine and bromine that eventually breaks the ozone into oxygen molecules (O2). It is estimated that one chlorine atom destroys 100,000 ozone atoms before finally removed from the stratosphere. The ozone filters out harmful ultraviolet rays (UV). Less ozone means higher levels of UV on earth. More depletion of ozone can cause larger increase of incoming UVs. UV has been linked to skin cancer, cataracts, damage to plastics and harm to certain crops. Some UV reaches the earth even without ozone depletion. With the ozone depleting, even more UV is entering earth ( Air Pollution / OAR pg. 2). Smog, a combination of smoke and fog, is basically a mixture of fog and some air pollutants. These air pollutants are nitrogen oxides, sulfur dioxide, carbon monoxide, ozone, and volatile organic compounds. Majority of these pollutants come from automobile exhausts which is the cause of smog in large cities like, Los Angeles, Chicago, New York, etc. Smog destroys vegetation and forests. It also affects human health causing irritation in eyes and lungs ( Gay pg. 18 ).Some pollutants, collectively known as hazardous air pollutants (HAPs), can cause toxic effects on human and other living things. Most HAPs are released from man-made sources, such as factories and automobiles. Toxic pollutants can cause serious health problems. For example vapor from gasoline can cause damage to brain and nervous systems ( Air Pollution / OAR pg. 4 ).To control air pollution in the United States, Congress passed the nations first Clean Air Act in 1963, which provided funds for state and local agencies to establish regulations for air quality. But the regulations were not adequate. By the end of the 1960s, it was clear that the national standards were need...
