Air pollution Essay Example | Topics and Well Written Essays - 2500 words

Air pollution - Essay Example From this research it is clear that air pollution has become a major environmental health problem affecting both developed and developing countries throughout the world. The consequence has been that air pollution is causing human health problems as well as damage to vegetation, crops, wildlife, materials, buildings and even the climate. In the U.S., the largest sources of air pollution, in order of importance, are: 1) transportation, mainly automobiles and trucks; 2) electric power plants that bum coal or oil; and 3) industry, for which the major sources include steel mills, metal smelters, oil refineries, and paper mills. The most common air pollution problem resulting from these emission sources is ground-level ozone (O3), According to the United States Environmental Protection Agency (EPA), non-attainment of EPA requirements for O3 is the most common air pollution problem facing large cities in the U.S. It is estimated that, 160 million people in the U.S. lived in areas that are in non-attainment of healthful O3 levels (Organization for Economic Co-operation and Development [OECD]. In the past, efforts to reduce air pollution have consisted primarily of "command and control" programs that involve enforcement of government regulations designed to reduce toxic emissions. Such programs have proven highly effective in reducing industrial, point source pollution and causing auto manufacturers to produce cleaner burning automobiles.... The stratospheric level of the earth's atmosphere lies directly above the troposphere, which extends from sea level to approximately 8-9 miles above the earth's surface. It is in the troposphere that nearly all forms of life on earth reside. Within the stratosphere lies a highly concentrated level of ozone, commonly referred to as the ozone layer. The highest concentrations of O3 within the stratosphere occur between 11-15 miles above the earth's surface. This stratospheric ozone layer is essential to the maintenance of life on earth, protecting the earth's inhabitants from the sun's harmful ultraviolet (UV) radiation (Buchholz 1). Thus, free of human interference, the stratospheric ozone layer is continually maintaining a dynamic equilibrium between ozone production and ozone destruction that maintains the earth's protective ozone layer. While O3 also occurs naturally in very small amounts at ground level in the troposphere, in urban areas throughout the U.S., tropospheric O3 levels are rising to unhealthful levels (Buchholz 1). In affected urban areas, O3 air pollution reaches its highest level between the months of May and September when temperatures are high and sunlight abundant. O3 forms at ground level when volatile organic compounds (VOC's) combine with nitrogen dioxides (NOx) in the presence of heat and light (Buchholz 1). NOx is formed via the burning of fossil fuels at high temperatures, and is the primary precursor to O3, NOx and VOC's, are emitted into the air by motor vehicles, electrical power plants and other industrial plants. Because the O3 molecule is highly reactive, it acts as a powerful oxidant. Consequently, ground-level ozone negatively affects human