Health and Pollution : Glossary

There are 75 documents in this section.

  • Coal

    3 November 2000

    A black or brown combustible material composed of carbon (C), various carbon compounds and other materials such as sulphur (S). The most abundant of the fossil fuels, it was formed through the accumulation of vegetable matter over millions of years in environments (e.g. swamps, deltas) which reduced the rate of decay of the organic material and allowed the preservation of the solar energy to absorbed by it when it was growing. When coal is burned, it is that energy which is released.

  • Fuel cells

    3 November 2000

    Fuel cells are electrochemical devices that convert a fuel's energy directly to electrical energy through a chemical reaction instead of combustion. Fuel cells operate much like continuous batteries when supplied with fuel to the anode (negative electrode). Fuel cells forego the traditional extraction of energy in the form of combustion heat, conversion of heat energy to mechanical energy (as with a turbine), and finally turning mechanical energy into electricity (e.g. using a dynamo). Instead, fuel cells chemically combine the molecules of a fuel and oxidizer without burning, dispensing with the inefficiencies and pollution of traditional combustion.

  • Methane

    3 November 2000

    A simple hydrocarbon gas (CH4) produced during the decomposition of organic material under anaerobic conditions. It is the main constituent of natural gas and therefore and important fuel.

  • OPEC

    3 November 2000

    Organisation of Petroleum Exporting Countries. A group of Middle Eastern, Asian, African and Latin American nations that includes the world's major petroleum producers and exporters. They came together in 1960, recognising the importance of oil as a source of future development, and with the intention of using their petroleum resources to advance their economic interests.

  • Petroleum

    3 November 2000

    A mixture of naturally occurring hydrocarbons, that may exist in a solid (e.g. bitumen), liquid (e.g. crude oil) or gaseous state (e.g. natural gas). It commonly contains variable amounts of other chemicals such as sulphur (S) and nitrogen (N). Petroleum is the end-product of the partial decay of living organisms which once inhabited the world's oceans. As they died they sank to the bottom of the oceans, where the anaerobic conditions allowed them to be preserved.

  • AIDS

    29 August 2000

    Acquired immune deficiency syndrome - a fatal disease caused by a virus (HIV) which destroys the immune system's ability to fight off infection.

  • Endocrine-disrupting chemicals

    22 August 2000

    Chemicals that can weakly mimic, or modify the action of human hormones. For example, some chemicals found in plastics, pesticides and industrial products are weakly oestrogenic, modifying the action of the female hormone. (Hormones are chemical messengers which govern human development and control or mediate vital bodily functions).

  • Environmental pollution

    22 August 2000

    The contamination of the physical and biological components of the earth/atmosphere system to such an extent that normal environmental processes are adversely affected.

  • Epidemic

    22 August 2000

    Appearance of abnormally high number of cases of infection in a given population; can also refer to non-infectious diseases (e.g. heart disease) or acute events such as chemical toxicity.

  • Epidemiology

    22 August 2000

    The study of the distribution and determinants of health-related states or events in specified populations. Epidemiology is the basic quantitative science of public health.