The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.
Volatile organic compounds (VOCs) are small organic molecules that take part in photochemical reactions in the atmosphere, resulting in smog. They have low boiling points and vaporize easily. When present in the atmosphere, VOCs, such as benzene and ethylbenzene, are not removed by passing the air through a filter. The atmosphere also contains nonvolatile organic compounds and semivolatile species such as anthracene and nicotine. The latter separate partly on a filter and partly in the gas phase, depending on temperature. VOCs (isoprene and pinene) are emitted by living trees and decomposition of vegetation. The process of refining crude oil to various fuels and the use, spillage, and incomplete combustion of those fuels in vehicles is another major source of VOCs. When mixed with nitric oxide emissions, mainly from combustion sources, and allowed to stagnate in intense sunlight, this mix forms ozone (a colorless gas) and oxidizes much of the VOCs to involatile particulate matter that scatters and absorbs light. This combination is termed photochemical smog.
Environmental destruction as a tool of war is not new. In 146 B.C.E., at the end of the Third Punic War, Roman soldiers reportedly plowed salt into the fields of Carthage, leaving them infertile and ensuring that the North African city would never again be a challenge to the Roman Empire.
U.S. Environmental Protection Agency. "Organic Gases (Volatile Organic Compounds—VOCs)." Available from http://www.epa.gov/iaq.