Health and Pollution : Glossary

There are 75 documents in this section.

  • Hydrocarbons

    9 August 2001

    Air pollutants that are important precursors of smog. These chemical compounds are generally released as unburned or incompletely burned residue when carbon-containing fossil fuels such as coal, oil, and natural gas are burned in car or truck engines.

  • Acid deposition

    8 August 2001

    The airborne transport and descent to earth of acids and acid-forming chemicals, particularly those released by power plants, industry, and vehicles.

  • Bio-indicators

    8 August 2001

    Fish and other freshwater organisms from polluted waterways, for example, whose death or unusual behaviour may indicate the presence of hazardous pollutants that have escaped other detection methods.

  • Chlorinated hydrocarbon

    8 August 2001

    A class of synthetic chemicals first produced in the 1930s, including potent pesticides such as DDT and other compounds that do not break down in the environment and can be concentrated to poisonous levels in the fatty tissues of fish, birds, and mammals.

  • Erosion

    30 April 2001

    Natural physical and chemical processes by which the soil and the rocks of the Earth's crust are continuously abraded and corroded. Most erosion results from the combined activity of several factors, such as heat, cold, gases, water, wind, gravity, and plant life. In some regions one of these may predominate, such as wind in arid areas. Erosion is grouped into two major divisions: geological erosion, which affects rocks as well as soil, and soil erosion."Erosion," Microsoft® Encarta® Online Encyclopedia 2001 © 1997-2001 Microsoft Corporation. All rights reserved.

  • Endangered species

    16 March 2001

    Species of plants or animals threatened with extinction because their numbers have declined to a critical level as a result of overharvesting or because their habitat has drastically changed. That critical level is the minimum viable population (MVP), and represents the smallest number of breeding pairs required to maintain the viability of species.

  • Ecology

    16 March 2001

    Originally defined by Ernst Haeckel in 1866, ecology is the study of the relationships that develop among living organisms and between these organisms and the environment.

  • Conservation (nature)

    9 March 2001

    Protection against irreversible destruction and other undesirable changes, including the management of human use of organisms or ecosystems to ensure such use is sustainable.

  • Carbon dioxide (CO2)

    3 November 2000

    One of the major greenhouse gases. Human-generated carbon dioxide is caused mainly by the burning of fossil fuels.

  • Carbon tax

    3 November 2000

    A policy that would tax fossil fuels according to the amount of carbon they contained. This would reduce the demand for fossil fuels in general and cause a realignment away from coal to less polluting natural gas, or renewable sources of energy.