Air Pollution :: essays research papers

Air PollutionCFish Mr. Nollen biological science 2B8 May, 1996The Problem     Contamination of the atmosphere by gaseous, liquid, or good wastes orby-products that can endanger human health and the health and public assistance of plantsand animals, or can attack materials, reduce visibility, or produce unsuitableodors. Among air pollutants emitted by natural sources, only the radioactivegas atomic number 86 is recognized as a major health threat. A byproduct of theradioactive decay of uranium minerals in certain kinds of rock, radon seeps intothe basements of homes construct on these rocks. According to recent estimates bythe U.S. government, 20 percent of the homes in the U.S. harbor radonconcentrations that ar high enough to pose a risk of lung cancer.     Each year industrially developed countries generate billions of scores ofpollutants. The level is usually given in terms of atmospheric concentrationsor, for gases in terms of parts per million, that is, number of pollutantmolecules per million air molecules. Many go farther from directly identifiablesources sulfur dioxide, for example, comes from electric power plants burningember or oil. Others are formed through the action of sunlight on previouslyemitted reactive materials. For example, ozone, a dangerous pollutant in smog,is produced by the interaction of hydrocarbons and nitrogen oxides under theinfluence of sunlight. Ozone has also caused serious crop damage. On the otherhand, the discovery in the 1980s that air pollutants such as fluorocarbons arecausing a loss of ozone from the earths protective ozone layer has caused thephasing break through of these materials.Current information about the problem     The tall smokestacks used by industries an utilities do not removepollutants but simply boost them high into the atmosphere, thereby reducingtheir concentration at the site. These pollutants may then be transported overlarge dist ances and produce adverse effects in areas far from the site of theoriginal emission. mho dioxide and nitrogen oxide emissions from the centraland easterly U.S. are causing acid rain in New York State, New England, andeastern Canada. The pH level, or relative acidity, of many freshwater lakes inthat role has been altered so dramatically by this rain that entire anglepopulations have been destroyed. Similar effects have been observed in Europe.Sulfur dioxide emissions and the subsequent formation of sulfuric acid can alsobe responsible for the attack on limestone and marble at large distances fromthe source.     The universal increase in the burning of coal and oil since the late forties has led to ever increasing concentrations of carbon dioxide. Theresulting "greenhouse effect", which allows solar energy to enter the atmospherebut reduces the remission of infrared shaft of light from the earth, could