Ch. 15 Outline PDF

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Detailed outline of Environmental Science Foundations and Applications. Friedland, Relyea, Courard-HauriISBN:9781429283311 Ch. 15...

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Ch. 15 Air Pollution: Causes, Effects, and Stratospheric Ozone Depletion

15.1 Air pollutants are found throughout the entire global system ● Air pollution = The introduction of chemicals, particulate matter, or microorganisms into the atmosphere at concentrations high enough to harm ecosystems ○ Typically refers to pollution in the troposphere ○ Can occur naturally or from human activities ● In general. The air is much cleaner today than it was 40 years ago ○ Indoor pollution is also a human health issue in Asia, Africa, and South America ● Inputs of the system are the creators of air pollutants ● Outputs of the systems are things in the atmosphere that remove pollutants ● The atmosphere is considered a public resource ○ 1970 - U.S. Clean Air Act identifies six pollutants that significantly threaten human well-being, ecosystems, or structures ■ Carbon dioxide was not included in this list ● Particulate matter → Solid or liquid particles suspended in air ○ Comes from the combustion of wood, animal manure, and other biofuels ○ Ranges in size ○ Haze = Reduced visibility caused primarily by particulate matter ● Photochemical oxidants → A class of air pollutants formed as a result of sunlight acting on compounds like nitrogen oxides ○ Smog is the mixture of oxidants and particulate matter

● Primary pollutants → Polluting compounds that come directly out of the smokestack, exhaust pipe, or natural emission source ○ Secondary pollutants → Primary pollutants that have undergone transformation in the presence of sunlight, water, oxygen, or other compounds ■ Ozone is considered a secondary pollutant

15.2 Air pollution comes from both natural and human sources ● Volcanoes, lightning, forest fires, and plants release compounds that can be classified as pollutants ● Emissions from human activities are measured and regulated by the EPA ○ The EPA also categorizes pollutants by their source ○ On-road vehicles are the largest source of carbon monoxide and nitrogen oxides ● The Clean Air Act requires that the EPA establishes standards to control pollutants that are harmful to human welfare...