Examples of Air Pollutants

Most of the information on the effects of air pollution on humans comes from acute pollution episodes such as the ones in Donora and London. Illnesses may result from chemical irritation of the respiratory tract, with certain sensitive subpopulations being more affected (1) very young children, whose respiratory and circulatory systems are poorly developed, (2) the elderly, whose cardiorespiratory systems function poorly, and (3) people with cardiorespiratory diseases such as asthma, emphysema, and heart disease. Heavy smokers are also affected more adversely by air pollutants. In most cases the health problems are attributed to the combined action of particulates and sulfur dioxides (SO2) no one pollutant appears to be responsible. Table 4.2 summarizes some of the major air pollutants and their sources and effects. 

Sulfur Oxides. Sulfur dioxide is a common component of polluted air that results primarily from the industrial combustion of coal, with soft coal containing the highest levels of sulfur. The sulfur oxides tend to adhere to air particles and enter the inner respiratory tract, where they are not effectively removed. In the respiratory tract, SO2 combines readily with water to form sulfurous acid, resulting in irritation of mucous 

Sulfur oxides, Coal and oil power plants Main component of acid deposition 

Nitrogen oxides Automobile emissions Fossil fuel power plants Pulmonary edema, impairs lung defenses Important component of photochemical smog and acid deposition 

Carbon monoxide Motor vehicle emissions Burning fossil fuels Incomplete combustion Combines with hemoglobin to form carboxyhemoglobin, poisonous Asphyxia and death 

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The effect of accumulation in various systems depends greatly on the quantity of pollutants involved. Many pollutants can be detected at concentrations lower than those necessary to affect human health. For pollutants which are eliminated slowly, individuals can be monitored over long periods of time to detect trends in body burden the results of these analyses can then be related to total pollutant exposure. Following are two examples of air pollutants that contribute to the total body burden for lead and carbon monoxide. 

List examples of air pollution effects on plants that cannot be detected by visual symptoms. 

An example of air pollution in a confined space is the air in an airplane. The air in commercial airplanes contains reduced levels of oxygen, increased levels of carbon monoxide, carbon dioxide, ozone, volatile organic compounds and particulate matter. These contaminants have led to cockpit crew, cabin crew, and passenger complaints of headache, fatigue, fever, and respiratory difficulties. Another example of confined space air pollution is the release of solvent fumes when interior walls of buildings with inadequate air circulation are painted. ... 

A final example of air pollution concerns is that of the fate of particles. 

The purpose of such scmbbing operations may be any of the following gas purification (eg, removal of air pollutants from exhaust gases or contaminants from gases that will be further processed), product recovery, or production of solutions of gases for various purposes. Several examples of appHed absorption processes are shown in Table 1. 

Air pollution (qv) problems are characteri2ed by their scale and the types of pollutants involved. Pollutants are classified as being either primary, that is emitted direcdy, or secondary, ie, formed in the atmosphere through chemical or physical processes. Examples of primary pollutants are carbon monoxide [630-08-0] (qv), CO, lead [7439-92-1] (qv), Pb, chlorofluorocarbons, and many toxic compounds. Notable secondary pollutants include o2one [10028-15-6] (qv), O, which is formed in the troposphere by reactions of nitrogen oxides (NO ) and reactive organic gases (ROG), and sulfuric and nitric acids. 

Code of Federal Regulations, Title 40-Protection of Environment, Chapter 1—Environmental Protection Agency, Appendix L, Example Regulations for Prevention of Air Pollution Emergency Episodes, 1,1 Episode Criteria, pp. 841-842. 

The harmful effects of air pollutants on human beings have been the major reason for efforts to understand and control their sources. During the past two decades, research on acidic deposition on water-based ecosystems has helped to reemphasize the importance of air pollutants in other receptors, such as soil-based ecosystems (1). When discussing the impact of air pollutants on ecosystems, the matter of scale becomes important. We will discuss three examples of elements which interact with air, water, and soil media on different geographic scales. These are the carbon cycle on a global scale, the sulfur cycle on a regional scale, and the fluoride cycle on a local scale. 

The major effects of air pollution on fabrics are soiling and loss of tensile strength. Sulfur oxides are considered to cause the greatest loss of tensile strength. The most widely publicized example of this type of problem has been damage to women s nylon hose by air pollution, described in newspaper accounts. The mechanism is not understood, but it is postulated that fine droplets of sulfuric acid aerosol deposit on the very thin nylon... 

One form of air pollution control regulation limits the pollution concentration at the owner s "fence line." Find an example of this type of regulation and discuss its pros and cons. 

Examples of point sources of air pollution, general control methods, and pollution prevention and energy saving practices... 

In addition to chemicals covered under TRI, many other chemicals are released. For example, the EPA Office of Air Quality Planning and Standards has compiled air pollutant emission factors for determining the total air emissions of priority pollutants (e.g., VOCs, SO, NO, CO, particulates, etc.) from many refinery sources. The EPA Office of Aerometric Information Retrieval System (AIRS) contains a wide range of information related to stationary sources of air pollution, including the emissions of a number of air pollutants which may be of concern within a particular industry. With the exception of volatile organic compounds (VOCs), there is little overlap with the TRI chemicals reported above. 

Temperature change with altitude has great influence on the motion of air pollutants. For example, inversion conditions result in only limited vertical mixing. The amount of turbulence available to diffuse pollutants is also a function of the temperature profile. The decrease of temperature with altitude is known as the lapse rate. The normal or standard lapse rate in the United States is -3.5" F/1,000 ft. An adiabatic lapse rate has a value of -5.4" F/1,000 ft. Temperature as a function of altitude is expressed by the following equation ... 

Sensitive Receptor the aqrv, or part thereof, that is the most responsive to or the most easily affected by the type of air pollution in question. For example, at Great... 

This section illustrates by way of example, the application of simphfied dispersion estimates to assessing a catastrophic venting operation. In this example, an analysis was performed to predict the fate of air pollutants, specifically vinyl chloride monomer (VCM), originating from an episode type upset (reactor blow) condition from a reaction vessel. 

This incentive problem is increased as the number of polluters and the number of land otvners increase so that it is difficult to pinpoint specific incidents of pollution and their effect on individuals. The case of air pollution from cars and multiple factories is a classic example of this information problem. In a large metropolitan area, there are millions of automobiles and many factories that could contribute to air pollution. There are also millions of individuals who could be harmed by that pollution. But it is generally difficult, if not impossible, for one individual to identify a specific problem they have experienced due to air pollution and then to pinpoint the source of that problem. Such situations, where property rights are... 

As informed Dr. A.I. Korableva from Institute for Environmental Management and Ecology under the National Academy of Sciences of Ukraine in the report "Environmental impact of automobile transport by example of Dnepropetrovsk", Dnepropetrovsk with its annual discharge of air pollutants of 177,000 t (as of 1996) is among the worst affected cities in Ukraine. In these, the automobile transport was found to be responsible for at least 30 % of the total emissions which are 15 times the maximum permissible level. Aside from the dust, chemical, photochemical and noise pollution, there is the aspect of street washout of automobile-related pollutants into the River Dnieper. The measured annual receipts of lead, particulates and petroleum derivatives via rainwater and thaw water to the river are 0.45, 80,000+ and 1.8+ t respectively. The actual levels of petroleum derivatives in storm water sometimes were 206 times the maximum permissible concentration (MPC) for the fishery basins. At 34 km downstream from the city, the estimated levels of petroleum derivatives and particulates are 61 and 10.8 times the respective MPCs. The airborne lead is mainly accumulated in the soil of housing areas. 

A miniaturized MB spectrometer MIMOS II was developed for the robotic exploration of Mars, where it provided fundamental information about mineralogical composition and alteration processes, helped to classify rocks and soils, aided geologic mapping, was instrumental in assessing habitability of past and present environments, and identified potential construction resources for future human explorers. The applicability of the instrument as a process monitor for oxygen production and prospecting tool for lunar ISRU has been demonstrated. The characterization of air pollution sources and the study of mixed-valence materials as a function of depth in soil are examples of terrestrial in situ applications. MIMOS lla with additional XRF capability will open up new applications. 

Notwithstanding the intellectual challenges posed by the subject, the main impetus behind the development of computational models for turbulent reacting flows has been the increasing awareness of the impact of such flows on the environment. For example, incomplete combustion of hydrocarbons in internal combustion engines is a major source of air pollution. Likewise, in the chemical process and pharmaceutical industries, inadequate control of product yields and selectivities can produce a host of undesirable byproducts. Even if such byproducts could all be successfully separated out and treated so that they are not released into the environment, the economic cost of doing so is often prohibitive. Hence, there is an ever-increasing incentive to improve industrial processes and devices in order for them to remain competitive in the marketplace. 

The effects of oxidant air pollutants on vertebrates can be segregated into direct and indirect categories. Direct effects are clinical and pathologic alterations of tissues that result from exposure to ambient air. Indirect effects result from alterations in numbers or distribution of the plant and animal populations exposed to ambient air. For example, if air pollution eliminates or thins numbers of a susceptible plant species, the food chain of the consumers that feed on it may break down. The result could be a simpler and less stable ecosystem, with fewer plants and animals in species and numbers. 

Some of the important reactions in contemporary technology involve NO, which is a designation of N2O, NO, and NO2, and was one of the first examples in this book. The formation of these molecules in combustion processes is a major source of air pollution, and the catalytic oxidation of NH3 to NO on R surfaces is used to produce nitric acid, a major industrial chemical. The decomposition of NO, to N2 is a major process in the automotive catalytic converter. 

Notwithstanding Tukulti s experience, the primary cause of air pollution for most of history has been wood or coal fires, especially in crowded urban communities. The streets of Rome, for example, were notorious for their terrible, smoky character, caused by thousands of wood and coal fires. In 61 c.E. the Roman philosopher Seneca described how this foul air affected his mood "As soon as I had gotten out of the heavy air of Rome and from the stink of the smokey chimneys thereof, he once wrote, "... I felt an alteration of my disposition. ... 

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