Air Pollution


Air Pollution

Tiffany Dixon

Dr. Collado

SOW 200 Social Problems

Union Institute University

August 18, 2009

Air pollution is a problem that we have noticed since the industrial revolution, when trees, houses and cars were covered in soot from the factories. People demand change; then, just as they are demanding it now. With all the talk of acid rain, global warming and ozone depletion it seems hopeless, but it isn??™t. Everyone can make a difference. After reading this you will understand the causes, effects and possible solution to the problems of acid rain, global warming and depletion. You will that things are bad but not hopeless.
Pollution is changing the earths atmosphere so that it lets in more harmful radiation from the sun. At the same time, our polluted atmosphere is becoming a better insulator, preventing heat from escaping back into space and leading to a rise in global average temperatures. Scientists predict that the temperature increase, referred to as global warming, will affect world food supply, alter sea level, make weather more extreme, and increase the spread of tropical disease. (D. Stanley Eitzen, 2008)
Most air pollution comes from one human activity: burning fossil fuels, natural gas, coal, and oil to power industrial processes and motor vehicles. Among the harmful chemical compounds this burning puts into the atmosphere are carbon dioxide, carbon monoxide, nitrogen oxides, sulfur dioxide, and tiny solid particles including lead from gasoline additives called particulates. Between 1900 and 1970, motor vehicle use rapidly expanded, and emissions of nitrogen oxides, some of the most damaging pollutants in vehicle exhaust, increased 690 percent. (D. Stanley Eitzen, 2008) When fuels are incompletely burned, various chemicals called volatile organic chemicals also enter the air. Pollutants also come from other sources. For instance, decomposing garbage in landfills and solid waste disposal sites emits methane gas, and many household products give off Volatile organic chemicals. (D. Stanley Eitzen, 2008)
Some of these pollutants also come from natural sources. For example, forest fires emit particulates and Volatile organic chemicals into the atmosphere. Volcanoes spew out sulfur dioxide and large amounts of pulverized lava rock known as volcanic ash. A big volcanic eruption can darken the sky over a wide region and affect the earths entire atmosphere. The 1991 eruption of Mount Pinatubo in the Philippines, for example, dumped enough volcanic ash into the upper atmosphere to lower global temperatures for the next two years. (D. Stanley Eitzen, 2008) Unlike pollutants from human activity, however, naturally occurring pollutants tend to remain in the atmosphere for a short time and do not lead to permanent atmospheric change. Once in the atmosphere, pollutants often undergo chemical reactions that produce additional harmful compounds. Air pollution is subject to weather patterns that can trap it in valleys or blow it across the globe to damage pristine environments far from the original sources.
Local and regional pollution take place in the lowest layer of the atmosphere, the troposphere, which extends from the earths surface to about ten miles. The troposphere is the region in which most weather occurs. (D. Stanley Eitzen, 2008) If the load of pollutants added to the troposphere were equally distributed, the pollutants would be spread over vast areas and the air pollution might almost escape our notice. Pollution sources tend to be concentrated, however, especially in cities. In the weather phenomenon known as thermal inversion, a layer of cooler air is trapped near the ground by a layer of warmer air above. When this occurs, normal air mixing almost ceases and pollutants are trapped in the lower layer. Local topography, or the shape of the land, can worsen this effect, an area ringed by mountains, for example, can become a pollution trap.
Smog is intense local pollution usually trapped by a thermal inversion. Before the age of the automobile, most smog came from burning coal and was so severe that in 19th-century London, street lights were turned on by noon because soot and smog darkened the midday sky. (D. Stanley Eitzen, 2008) Burning gasoline in motor vehicles is the main source of smog in most regions today. Powered by sunlight, oxides of nitrogen and volatile organic compounds react in the atmosphere to produce photochemical smog. Smog contains ozone, a form of oxygen gas made up of molecules with three oxygen atoms rather than the normal two. Ozone in the lower atmosphere is a poison; it damages vegetation, kills trees, irritates lung tissues, and attacks rubber. Environmental officials measure ozone to determine the severity of smog. When the ozone level is high, other pollutants, including carbon monoxide, are usually present at high levels as well.
In the presence of atmospheric moisture, sulfur dioxide and oxides of nitrogen turn into droplets of pure acid floating in smog. These airborne acids are bad for the lungs and attack anything made of limestone, marble, or metal. In cities around the world, smog acids are eroding precious artifacts, including the Parthenon temple in Athens, Greece, and the Taj Mahal in Agra, India. Oxides of nitrogen and sulfur dioxide pollute places far from the points where they are released into the air. (D. Stanley Eitzen, 2008) Carried by winds in the troposphere, they can reach distant regions where they descend in acid form, usually as rain or snow. Such acid precipitation can burn the leaves of plants and make lakes too acidic to support fish and other living things. Because of acidification, sensitive species such as the popular brook trout can no longer survive in many lakes and streams in the eastern United States. (D. Stanley Eitzen, 2008)
Humans are bringing about another global-scale change in the atmosphere: the increase in what are called greenhouse gases. Like glass in a greenhouse, these gases admit the suns light but tend to reflect back downward the heat that is radiated from the ground below, trapping heat in the earths atmosphere. This process is known as the greenhouse effect. Carbon dioxide is the most significant of these gases; there is 25 percent more carbon dioxide in the atmosphere today than there was a century ago, the result of our burning coal and fuels derived from oil. Methane, nitrous oxide, and chlorofluorocarbons (CFCs) are greenhouse gases as well. (D. Stanley Eitzen, 2008)
Scientists predict that increases in these gases in the atmosphere will make the earth a warmer place. They expect a global rise in average temperature somewhere between 1.0? and 3.5? C (1.8? and 6.3? F) in the next century. (D. Stanley Eitzen, 2008) Average temperatures have in fact been rising, and the years from 1987 to 1997 were the warmest ten years on record. (D. Stanley Eitzen, 2008) Most scientists are reluctant to say that global warming has actually begun because climate naturally varies from year to year and decade to decade, and it takes many years of records to be sure of a fundamental change. There is little disagreement, though, that global warming is on its way.
Global warming will have different effects in different regions. A warmed world is expected to have more extreme weather, with more rain during wet periods, longer droughts, and more powerful storms. Although the effects of future climate change are unknown, some predict that exaggerated weather conditions may translate into better agricultural yields in areas such as the western United States, where temperature and rainfall are expected to increase, while dramatic decreases in rainfall may lead to severe drought and plunging agricultural yields in parts of Africa, for example. (D. Stanley Eitzen, 2008)
Pollution is perhaps most harmful at an often unrecognized site, inside the homes and buildings where we spend most of our time. Indoor pollutants include tobacco smoke; radon, an invisible radioactive gas that enters homes from the ground in some regions; and chemicals released from synthetic carpets and furniture, pesticides, and household cleaners. When disturbed, asbestos, a nonflammable material once commonly used in insulation, sheds airborne fibers that can produce a lung disease called asbestosis. (D. Stanley Eitzen, 2008) Pollutants may accumulate to reach much higher levels than they do outside, where natural air currents disperse them. Indoor air levels of many pollutants may be 2 to 5 times, and occasionally more than 100 times, higher than outdoor levels. These levels of indoor air pollutants are especially harmful because people spend as much as 90 percent of their time living, working, and playing indoors. Inefficient or improperly vented heaters are particularly dangerous. (D. Stanley Eitzen, 2008)
Air pollution control is a race between the reduction of pollution from each source, such as a factory or a car, and the rapid multiplication of sources. Smog in American cities is expected to increase again as the number of cars and miles driven continue to rise. Meanwhile, developing countries are building up their own industries, and their citizens are buying cars as soon as they can afford them. Ominous changes continue in the global atmosphere. New efforts to control air pollution will be necessary as long as these trends continue.

Stanley Eitzen. (2008) Social Problems 11th Edition. Publisher: Allyn & Bacon, Inc.