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Air Pollution in Perspective
Tools to Assess Risks Associated with Air Pollution
Overarching Concepts
Exposure
Epidemiological Evidence of Health Effects
Pollutants of Outdoor Ambient Air
Classic Reducing-Type Air Pollution
Particulate Matter
Metals
Gas–Particle Interactions
Ultrafine Carbonaceous Matter
Chronic Effects and Cancer
Photochemical Air Pollution
Short-Term Exposures to Smog
Chronic Exposures to Smog
Ozone
Nitrogen Dioxide
Other Oxidants
Aldehydes
Formaldehyde
Acrolein
Carbon Monoxide
Hazardous Air Pollutants
Accidental versus “Fence-Line” Exposures
The Multipollutant Reality of Air Pollution
Conclusions
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Air Pollution in Perspective
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The second half of the 20th century was marked by remarkable changes in how the public viewed its relationship to the environment. Until that time, national pride and prosperity were often depicted as an expanse of urban factories with smokestacks belching opaque dark clouds of industrial effluent into a neutral blue sky. But the price of that unchecked human progress through the first half of the century led to several air pollution catastrophes highlighting the profoundly detrimental impact that reckless prosperity could have on the environment. These images of “modern” life gradually gave rise to public outcry for governmental action to protect air quality and public health—a challenge to industry that had been focused on economic growth alone. The ensuing 50 years of regulatory legislation in the United States and Western Europe along with cost-efficient innovations by the private sector have remade this industrial image in most technologically developed nations.
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Ironically, as regulatory control measures began to reduce emissions from stationary industrial sources of air pollution, highways to “open spaces” and urban flight took many people to the suburbs with its cleaner air and safe, comfortable lifestyle. Meanwhile, the developing world saw little of this growth and what has grown is frequently cast-off old technology and variants of exploitation by the Western corporations attracted by abundant resources, a cheap workforce, and few regulations of constraints. This situation has persisted into the 21st century but is evolving with broader globalization of improved technology and communication.
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The change in land use and demography in the United States in the 1950s and 1960s altered the national character and distribution of air pollution. The commute from suburban home to city workplace back to suburban home led increasingly to congested thoroughfares, whose emissions contributed to a photochemical cauldron of oxidant air pollution around expanding metro–suburban areas. Moreover, postwar population growth and rising expectations for a better (peace-time) standard of living led to unrestrained consumption, including inexpensive gasoline for commuting and recreation.
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Today, the search is worldwide for cheap oil to fuel transportation and goods movement ...