{"id":590,"date":"2021-07-02T10:43:03","date_gmt":"2021-07-02T10:43:03","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/suny-binghamton-envi101&envi201\/chapter\/__unknown__-3\/"},"modified":"2021-08-01T19:50:22","modified_gmt":"2021-08-01T19:50:22","slug":"chapter-15","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/suny-binghamton-envi101&envi201\/chapter\/chapter-15\/","title":{"raw":"Chapter 20 ~ Gaseous Air Pollution","rendered":"Chapter 20 ~ Gaseous Air Pollution"},"content":{"raw":"
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Key Concepts<\/h2>\r\n
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  1. After completing this chapter, you will be able to<\/li>\r\n \t
  2. Outline the major sources of emission of air pollutants associated with sulfur, nitrogen, and hydrocarbons.<\/li>\r\n \t
  3. Explain the difference between primary and secondary pollutants.<\/li>\r\n \t
  4. Contrast the environmental problems associated with stratospheric and tropospheric ozone.<\/li>\r\n \t
  5. Examine the importance of air pollutants to ecosystems and to human health.<\/li>\r\n \t
  6. Describe the patterns of pollution and ecological damage near point sources of air pollution.<\/li>\r\n<\/ol>\r\n

    Introduction<\/h1>\r\n

    Gaseous air pollutants are emitted from various natural sources, such as volcanoes and forest fires. However, anthropogenic emissions of some gases may be greater than the natural ones, and are increasing because of population growth and industrialization.<\/p>\r\n

    In ancient times, there was not much pollution. Nevertheless, even then local problems would have occurred. For instance, smoky wood fires used for cooking and warmth would likely have caused poor-quality air to occur inside of badly ventilated dwellings. Hunting cultures often used fire to drive game animals and improve local forage, and those burns would have resulted in large emissions of particulate carbon (soot), carbon dioxide, and other gases that would have temporarily impaired air quality. Overall, however, these effects were relatively minor.<\/p>\r\n

    Of course, as people became more numerous and industrialized, air pollution increasingly developed into a much bigger problem. When the Industrial Revolution began (around 1750), coal quickly became the major fuel used to generate heat and energy for machines, and that resulted in increasingly worse air pollution. The widespread use of coal led to severe pollution by sulfur dioxide (SO2<\/sub>) and soot in the industrial towns and cities of Europe and the Americas. Since 1900, burgeoning industrialization and new technologies such as power plants and automobiles have further increased the emissions of pollutants.<\/p>\r\n

    Air pollution can be especially severe in situations when the lower atmosphere is stable and calm. These conditions often occur beneath an atmospheric phenomenon called an inversion, in which a layer of cool air is trapped beneath a higher layer of warmer air (the more usual pattern is for temperature to cool with increasing altitude). An atmospheric inversion is a relatively stable condition that prevents polluted ground-level air from mixing with cleaner air from higher altitudes (see In Detail 20.1). If an atmospheric inversion is accompanied by fog, the pollution is known as smog (a word derived from \u201csmoke\u201d and \u201cfog\u201d). As recently as the 1950s, occasional so-called \u201ckiller smogs\u201d rich in SO2<\/sub>\u00a0and soot caused the deaths of thousands of urban people, and many more suffered from respiratory distress (pollution rich in SO2<\/sub>\u00a0is also called reducing smog). The most famous killer smogs occurred in London, Glasgow, some other industrial centers of Europe, and near Pittsburgh in the U.S.<\/p>\r\n

    Once scientists recognized the severe damage that was being caused by air pollution, governments began to pass laws to decrease the emissions. Pollution control became particularly vigorous after medical researchers discovered clear evidence of links between air quality and human diseases and deaths. Particular attention was paid to air pollution in urban environments, where the killer smogs were most frequent. Governments typically responded with important control actions, such as the following:<\/p>\r\n\r\n