Paper Example on Air Pollution

Although some air pollution is generated from natural sources, such as volcanic eruptions, most air pollutants stem from human activities that are concentrated in urban areas. Forms of transportation, notably the automobile, are primary sources of air pollution. Other sources include power plants and factories, burning fossil fuels, and burning forests and grasslands for farming and grazing, a common practice in the less-developed world.

Although progress has been made to improve air quality in some categories of pollutants, the overall situation is not encouraging. International common pool characteristics make difficult the search for solutions for globally generated air pollution, particularly in the area of acid rain and global warming. This chapter provides an overview of air pollution, its components, the laws and regulations governing air pollution, and the effects of air pollution on the environment at the local, national, and international levels.

SOURCESThe most common forms of air pollution are carbon moNOxide (CO), sulfur oxides, nitrogen oxides, particulate matter, and ground-level ozone. CO causes approximately 58 percent of the measurable air pollution in the United States. Sulfur oxides and nitrogen oxides contribute about 19 percent, with suspended particulate matter and other pollutants making up the balance.1 These pollutants originate from three primary sources: area sources (31 percent) that include homes and small businesses, mobile sources (39 percent) that include cars and airplanes, and point sources (30 percent) such as power plants.2CO, the most common air pollutant, is a colorless, odorless gas that forms when fossil fuels burn incompletely. Two-thirds of CO is produced by transportation (automobiles, trucks, etc.). In high concentrations, CO is deadly. In lower concentrations, it can lead to drowsiness, slowed reflexes, and a reduction in the bloods ability to carry and circulate oxygen. Although CO pollutants remain a common problem, EPA monitoring showed a decrease in the presence of CO in both atmospheric concentration and emissions from 1970 through 1999, particularly in urban areas where the greatest CO concentrations are found. Between 1990 and 2009, CO emissions dropped 53 percent.3 Its concentration in the atmosphere fell 80 percent in the same 29-year period, almost two-thirds of that coming in the 1990s.4 In 2009, the EPA reported that as much as 80 percent of CO emissions in cities come from motor vehicles. However, between 1990 and 2006, CO emissions have actually decreased 62 percent, while vehicle miles traveled were up 43 percent in the same period. The EPA credits cleaner cars for this improvement, which is attributable to the Federal Motor Vehicle Control Program for New Cars (new car standards).5Sulfur oxides are also common air pollutants. The sulfur oxides include sulfur dioxide (SO2) and sulfur trioxide (SO3). SO2 is a colorless gas that can aggravate respiratory diseases in humans, reduce plant growth, and corrode metal and stone. Electric utilities generate 66 percent of SO2 emissions in the United States, most of which come from coal-fired power plants.6 However, power plants under the EPA's Acid Rain Program [established in Title IV of the 1990 Clean Air Act Amendments (CAAA)] have shown steady improvement. They reduced SO2 emissions 50 percent from 1990 levels by 2008, HYPERLINK "https://jigsaw.vitalsource.com/books/9781317348580/epub/OEBPS/013_9781315664262_chapter5.html?create=true" \l "fn-fnrefn5_7" 7 and according to EPA reports, there was a 10 percent drop from 1999 to 2000 alone.8 During that same year, utilization was up 2.7 percent; thus, it seems that these pollution control measures did not hurt energy production.9Phase II of the Acid Rain Program began in 1999, meaning that the grace period (19941995) for utilities to begin minor reductions was over. Many utilities seemed to have complied. In fact, the EPA reports that SO2 emissions were further reduced another 5 percent from 2000 to 2004.10 Also, in 2004, the EPA only issued permits for 9.50 million tons of SO pollutants or 53 percent of actual emissions in 1980.

Many attribute the decrease in utility emission levels for SO2 in the United States to the burning of lower-sulfur fuels, the installation of pollution control devices, and the Acid Rain Program. Reports show that emission levels decreased from 17.3 to 5.7 million tons from 1980 to 2009, showing a 67 percent reduction in 29 years.11 The decrease has been even greater since the Program began in 1995. Between 1986 and 1995, national emissions of SO2 declined 18 percent and atmospheric concentrations declined 37 percent. From 1994 to 1995, the first year of the Program, concentration levels dropped dramatically (17 percent), as did emission levels (13 percent). These declines may be attributed to the success of the EPA Program to combat acid rain, which is caused in large part by atmospheric SO2.12 The impact of the program is highlighted by the fact that average annual SO2 atmospheric concentrations dropped 49 percent from 1990 to 2004.13Nitrogen oxides (NOx) also contribute to acid rain formation, but they have the added negative effect of contributing to the formation of smog and environmentally detrimental nitrate deposition. The electric power industry contributes 29 percent of NOx emissions in the United States annually.14 NOx emissions in the United States have declined slightly. From 1980 to 2008, average levels of nitrogen oxides in the atmosphere decreased 36 percent.15 The entire United States finally reached compliance with national air quality standards for NOx when Los Angeles attained EPA standard levels in July 1998. Between 2000 and 2005, average nitrogen oxide emissions have decreased 14.8 percent.16 Roughly 40 percent of all nitrogen oxides come from stationary fuel combustion sources, mostly utilities; much of the remainder comes from motor vehicles and jet-propelled aircraft.17 It is important to note that these pollution reductions have been achieved even though energy consumption has increased 20 percent since 1990.18Finally, ambient suspended particulate matter (tiny fragments of liquid or solid matter floating in the air) has seen the national average decrease by 38 percent in 2009 since 1990.19 These decreases are due in part to a reduction of industrial activities and the installation of pollution control equipment. Coal- fired power plants, as in the case of SO2 emissions, represent the largest source of particulate matter.20In July 1987, the EPA revised its standards to monitor only those particles designated PM10 (particulate matter with a diameter less than or equal to a nominal 10 microns). These particles are considered small enough to pose a health risk because their size allows them to penetrate the most sensitive regions of the respiratory tract. From 1988 to 1995, PM10 concentrations fell 22 percent, while emissions declined 17 percent.21 However, in 1996, the EPA reported that 78 areas still did not meet the standard for PM10.22 From 1990 to 2009, overall PM10 concentrations fell 38 percent, while emissions declined by approximately 67 percent.23 However, in 2010, the EPA reported that 45 areas, 8 areas with a classification of serious and 37 with a classification of moderate, did not meet the standard for PM10.24Moreover, in July 1998, the EPA promulgated new standards for the release of particulate matter and ground-level ozone. These new standards included regulations that address particulate matter four times smaller than PM10 (PM2.5), as well as the amount of time that particulate matter of certain sizes may be present in a specified area. In the case of ozone, the new standards require assessments of attainability to take place over a much longer period. This allows for a much more accurate indicator of the ozone danger. The EPA considered these new regulations necessary to prevent 15,000 premature deaths, 350,000 cases of aggravated asthma, and 1 million cases of significantly decreased lung function in children.25 In September 2006, the EPA strengthened the PM2.5 24-hour standard from 35 micrograms per cubic meter (ug/m3) to 65 ug/m3. The 2006 revisions revoked the annual PM10 standard for lack of evidence linking health problems to long-term exposure to coarse particle pollution.26The first year that the EPA received complete data on PM2.5 was 1999. By 2009, the national average had decreased by 27 percent. PM10 air concentrations were down 38 percent from 1990 to 2009, and SO2 (sulfates cause about half of PM2.5 concentrations) was down 65 percent.27Yet, there are some groups that protested these changes in EPA standards. The American Trucking Association challenged the new EPA standards for PM2.5 and ozone in 1999, claiming that these new regulations were legislation, and Congress did not have the authority to delegate to the EPA this law-making function through the 1990 CAAA. On February 27, 2001, the U.S. Supreme Court unanimously ruled that the act is indeed constitutional and that the EPA can set National Ambient Air Quality Standards (NAAQS) based solely on public health considerations, regardless of the potential cost to industry or others.28Ground-level ozone (commonly referred to as smog) is not directly emitted into the air. Rather, it is a poisonous form of pure oxygen that is created when sunlight reacts with nitrogen oxides and volatile organic compounds (VOCs) in the air.29 VOCs come from three sources: point sources, area sources, and motorized vehicles. Point sources, or industries that use chemicals or solvents in their processing, account for approximately 30 percent. Area sources make up 20 percent of emissions and are usually composed of small emitters such as dry cleaners and print shops. Finally, automobiles contribute 50 percent to total VOC content in the air.30 In 2002, the EPA reported a 40 percent decrease in anthropogenic (human-made) VOCs over the preceding 20 years. In 1999, industrial processes produced about 44 percent of VOCs nationwide, transportation sources accounted for about 47 percent, and solvent use contributed to about 26 percent of total U.S. VOC emissions.31 Although many areas came close to meeting ozone standards in the mid-1980s, relaxed enforcement in the late 1980s resulted in 96 cities being categorized as nonattainment sites in 1991. But increased efforts during the early 1990s led to the decrease in the number of nonattainment sites. By 1995, just 68 sites were in violation of NAAQSs for ground-level ozone. In 2006, just 40 areas were found to be in violation of eight-hour ozone standards, with only 4 being considered as serious or worse. The remaining areas were considered either serious or marginal.32 This drastic improvement is partly due to the revocation of one-hour ozone standards for all but three areas in June 2005. Overall, air concentrations of ozone are down 29 percent from 1980 levels, with a 16 percent improvement since 1990.33Health EffectsAlthough it is difficult to establish a direct causal link between a specific pollutant when it is in the atmosphere and a particular disease or death, many studies have shown that such relationships exist. Research has found air pollution to be associated with higher mortality rates and an increase in adverse health effects.34 Evidence strongly suggests that pollution from the burning of fossil fuels leads to the premature death of between 30,000 and 35,000 Americans each year.35 The elderly, infants, and children are particularly susceptible to harm from air pollution, as are adults with respiratory problems.

The interactive effects of pollutants in the atmosphere complicate the task of establishing direct links between air pollution and human health. The synergistic interactions of various pollutants...