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.
Release of material into the environment either by natural or human-caused processes. This term is used especially in describing air pollution for volatile or suspended contaminants that result from processes such as burning fuel in an engine. Definitions of pollution are complicated by the fact that many of the materials that damage or degrade our atmosphere have both human and natural origins. Volcanoes emit ash, acid mists, hydrogen sulfide, and other toxic gases. Natural forest fires release smoke, soot, carcinogenic hydrocarbons, dioxins, and other toxic chemicals as well as large amounts of carbon dioxide. Do these emissions constitute pollution when they originate from human sources but not if released by natural processes? Is it reasonable to restrict human emissions if there are already very large natural sources of those same materials in the environment? An important consideration in answering these questions lies in the regenerative capacity of the environment to remove or neutralize contaminants. If we overload that capacity, a marginal additional emission may be important. Similarly, if there are thresholds for response, an incremental addition to ambient levels may be very important.