Environmental Issues of Air Pollution - Essay Example

? Table of Contents Environmental Science: Air Pollution Introduction Air pollution has become a major environmental health problem affecting both developed and developing countries throughout the world (Nadakavukaren, 45). 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 (McKenzie et al. 463). 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 (Crpc-La.org 2). 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] 4). 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 (Environmental Protection Agency [EPA], ‘Cap and Trade Basics’ 1). While these government controls continue to effectively lower industrial emissions and reduce pollutants emitted from vehicles, O3 precursor, NOx, continues to be emitted into the air at increasing levels. Problems underlying ever increasing auto emissions of NOx and subsequent development of ground-level ozone air pollution are complex and multifaceted, requiring solutions that are more complex and wider in scope than traditional command and control methods. Ground-level Ozone and Human Health Effects O3 is a colorless, odorless gas that occurs naturally in relatively high concentrations in the stratosphere, which lies approximately 9-22 miles above the earth's surface. 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 health as well as the health of plants, and ecosystems. The adverse health effects resulting in exposure to ground-level ozone are numerous, and researchers estimate that one in three people in the U.S. are at risk for experiencing one or more of these health effects (EPA ‘Smog—Who Does It Hurt’ 2). Hospitalizations and emergency visits for respiratory related illness also show a significant rise on days when ozone levels are high. Burnett et al. (p. 130) performed a 15-year study in Toronto, Canada, examining the association of daily levels of gaseous air pollutants and particulate matter with daily hospitalizations due to asthma, obstructive lung disease, respiratory infection, heart failure, ischemic heart disease, cerebral vascular disease and peripheral vascular disease. After factoring out confounding factors such as temperature, day of week, climate, and humidity, results showed that O3 air pollution made a significant contribution to hospital admissions. Interestingly, three auto-related pollutants made a significant contribution to hospital admissions, with NOx, ozone's precursor, making the largest contribution (Burnett 137-139). Because O3 is a very strong oxidant, it causes adverse health effects to the respiratory system, exposed mucous membranes and even the immune system. While exposure to O3 affects individuals differently, symptoms may include one or more of the following: shortness of breath, chest pain, wheezing, coughing, headache, nausea, malaise, and eye irritation. Individuals may experience any variety of these symptoms at O3 levels found in most large urban areas throughout the U.S. Respiratory health effects are the most common result of exposure. Because O3 is highly reactive, it causes damage to lung tissue, increases lung sensitivity to other irritants, reduces the lung's ability to fight respiratory infection, and reduces lung function (Enami 7365). O3 expresses its oxidative qualities by interacting with biomolecules in the lungs, forming ozonides that then become free radicals. Free radicals then interact with various parts of the lung, causing inflammation and damage throughout (Enami 7365). As O3 reacts with the lung's biomolecules and incoming O2 in the airways, chemical bonds form and reform in different ways, causing inflammation in the membrane lining of the airways. The airways react by covering affected areas with fluid and by contracting muscles. These actions cause a reduction in the diameter of the airways resulting in decreased lung capacity. Another important consequence of over-exposure is a reduction in the airway's ability to provide a protective barrier against infectious agents and other irritants (Miller and Hurley 136).O3 damages the cilia which line the lung's airways. This cilia lining is important to lung function because in protects the lungs by removing foreign particles. Unhealthful levels of O3 damage this delicate cilia lining by slowing down or stopping the cilia's activity altogether. At higher levels of O3 exposure, patches of the lung's cilia may die and disappear altogether (Rajhans & Pathak 10). While the health effects of short-term exposure to ozone, such as occurs in laboratory studies, are reversible, lung damage resulting from long-term exposure may not be, Animal toxicology studies show that chronic exposure to concentrations of .20 ppm or less of O3 can cause changes in the small airways that are similar to changes that occur in the lungs of an individual in the early stages of chronic obstructive lung disease. Sun et al. (p. 3003-3004) reported that when laboratory animals experienced chronic exposure to O3 levels commonly found in U.S. cities, they developed permanent scarring in the lungs that resulted in long-term reduction of lung capacity. It appears that long-term exposure to O3 effects human lungs in the same manner (Sun et al. 3004). Strategies to Reduce Tropospheric Ozone Levels 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. In 1963, the first Clean Air Act (CAA) was passed and in 1970, and 1990, amendments to the CAA were passed which gave the EPA the responsibility and legal authority to set healthful air pollution standards, to put limits on point source and mobile emissions, and to enforce these new standards. As a result of the Clean Air Act amendments of 1970 and 1990, air quality in the U.S. has shown significant improvement. Between 1970 and 1993, lead emissions from industrial sources decreased by 91%, and the move from leaded to unleaded gas reduced lead emissions even further (EPA ‘National Air Pollutant Emission Trends’ ES-5). These improvements in air quality and emission reduction show that government regulation and control is highly effective in reducing industrial, point source pollutants and in providing incentive for manufacturers to produce cleaner burning automobiles. Despite these improvements, however, ground-level O3 air pollution remains the most difficult air pollution problem to control. While the government controls continue to effectively lower industrial emissions and reduce pollutants emitted from vehicles, O3 precursor, NOx, continues to be emitted into the air at increasing levels. The EPA reports that since 1970, as the aforementioned air pollutant emissions showed decline, NOx emissions increased approximately 10% (Kahn 10). This increase in NOx emissions is attributable to increases in usage of motor vehicles and increased usage of higher polluting vehicles. Another factor that contributes to increases in NOx emissions is the fact that increasing percentages of workers are commuting to work in single occupancy vehicles. Increases in miles driven in single-occupancy vehicles accompanied by increases in growth and demand for travel have counteracted the benefits of cleaner burning cars and gasoline. Utilizing Behavior Change Theory to Develop Effective Interventions Problems underlying ever increasing auto emissions of NOx and subsequent development of ground-level ozone air pollution are complex and multifaceted, requiring solutions that are more complex and wider in scope than traditional command and control methodologies. New technologies need to be developed, alternatives need to be more accessible and convenient, employers need to be supportive, housing and development patterns need to be altered, and the public needs to be convinced to utilize transportation alternatives. Such is the case with many environmental problems that are behaviorally based. The EPA has recognized that many environmental problems have deep underlying factors that must be addressed in order for long-term solutions to take place. Such underlying issues may include but are not limited to community development patterns, and social factors (EPA ‘Air, Climate and Energy’ 3). The EPA's "Community-Based Air Pollution Projects" is an excellent example of the type of program that could be highly effective in addressing issues associated with increased automobile usage (EPA ‘Community Based’ 1). The programs help communities develop multifaceted strategies to address behaviorally based environmental problems that cannot be solved with traditional command and control policies. These programs seek solutions to these more complex environmental problems by addressing the underlying factors that contribute to environmentally unfriendly behaviors. Effective programs can then be developed which integrate sustainable environmental practices with the economic and social objectives of the community (EPA ‘Air, Climate and Energy’ 3). A multifaceted approach such as this could be quite effective in addressing issues that underlie the problem of ever increasing single-occupancy vehicle usage. Many factors other than air quality determine individual transportation choices, and barriers to using alternatives to single-occupancy commutes or living closer to worksites are numerous. Barriers may include but are not limited to increased time required when using alternative transportation, safety concerns pertaining to mass transit, problems of convenience, employment issues, high cost of living in cities were people work, and increased crime in inner cities. The Department of Transportation (DOT) is aware of many of these barriers and has several programs in place to help make the use of alternative transportation more amenable the needs of the public. For example, the "Congestion Mitigation and Air Quality Improvement Program" (CMAQ) provides funding for surface transportation programs that improve air quality by reducing auto emissions in urban areas that are in non-attainment of O3 (DOT, 2). Other programs funded by CMAQ are aimed at reducing O3 by developing programs that improve traffic flow and reduce congestion, increase convenience and usage of ride-sharing, increase use of vehicle emission inspection and maintenance programs and utilize education and outreach programs to increase public knowledge (DOT 9). The EPA and DOT recommend development of programs that will increase usage of alternative transportation and decrease motor vehicle usage. The DOT warns, however, that programs aimed at providing alternatives to single-occupancy vehicle usage can only be effective if the public actually utilizes such alternatives. Therefore, the EPA and DOT strongly encourage aggressive marketing approaches and public education and outreach programs aimed at increasing the public's knowledge of O3 air pollution and the development of programs that will increase usage of alternative transportation (EPA ‘Education/Outreach Award Recipients’ 1; DOT 10). Moving towards decreasing usage of single-occupancy vehicles and towards more environmentally friendly modes of transportation in order to reduce O3 air pollution is a social change supported by health professionals as well (EPA ‘Indoor Air Pollution’ 1). Organizations such as the ALA is highly involved in advocacy work aimed at increasing air quality standards and promoting changes that will bring about decreases in O3 air pollution (EPA ‘Indoor Air Pollution’ 1). Health educators can also play a vital role in bringing about social changes that will result in more sustainable transportation practices. The field of health education has been highly successful in applying human behavior theories to the understanding of various health-related behaviors as well as using these theories to guide development of programs that have proven highly effective in bringing about behavior change (EPA ‘Indoor Air Pollution’ 1). Conclusion Air pollution has been troublesome to human health since the beginning of time and now it has reached serious proportions with the dawn of industrialization. The main constituent of photochemical pollution is O3 and this troublesome pollutant has now reached unhealthful levels in cities throughout the United States and the industrialized world. At ground level, in the troposphere, high levels of O3 pose health risks to humans and plant life. Damage to respiratory health is the most common health effect of over-exposure, and includes damage to lung tissue, increased lung sensitivity to other irritants, reduction in the lung's ability to fight respiratory infection, and reduction in lung function. Currently, automobiles are the largest contributor to the formation of ground­ level ozone therefore there is a need to increase usage of alternative sources of transportation in order to reduce levels of O3 air pollution. Traditional "command and control" methods for reducing various environmental pollutants are not sufficient for controlling the nation's O3 air pollution problem. Such methods are highly effective in controlling "point source" pollutants, i.e., those that are released from specific locations such as power plants or industrial sites (McKenzie et al. 463). Reduction of "non-point source" pollutants, those that enter the environment from broad, undefined locations such as motor vehicle exhaust, remain a formidable challenge. Command and control methods are currently being implemented and are highly effective in reducing emissions of O3's precursors, NOx and VOCs, from industrial sites. However, NOx emissions from motor vehicles, a non-point source pollutant, have increased 10% since 1970 despite legislation requiring cleaner burning motor vehicles (Kahn 10). This increase in NOx emissions is attributable to increases in usage of motor vehicles and increased usage of SUV' s and trucks. The EPA and the DOT recognize that reducing O3 air pollution will require reducing dependency on single occupancy vehicles, and they are using a multifaceted approach to developing programs to accomplish this. Such programs involve development and implementation of new transportation technologies, increasing use and convenience of current alternative transportation resources, and developing educational and incentive programs to encourage the public to utilize these alternatives (DOT, 2). Far more money and effort have gone into development of new technologies, resulting in a current need for educational and incentive programs aimed at encouraging the public to utilize sources of alternative transportation. Health educators can be highly instrumental in developing programs that will increase usage of alternative transportation. Such programs can be instrumental in removing barriers to alternative transportation usage and in promoting change. Work Cited Buchholz, Rogene A. Ozone Depletion. Encyclopedia of Business Ethics and Society. SAGE Publications, 2007. Burnett, R. T., Smith-Doiron, M., Stieb, D., Cakmak, S. & Brook, J. 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