Health and Pollution : Glossary

There are 75 documents in this section.

  • Ozone hole

    26 September 2001

    A popular name given to a phenomenon discovered in 1987, when scientists measured unexpectedly low ozone concentrations in the stratosphere above the South Pole during the Antarctic spring. It is now generally accepted that the loss of stratospheric ozone is caused by chemical reactions initiated by chlorofluorocarbons.

  • Pollution

    26 September 2001

    An undesirable contaminate (gas, liquid, noise, solid) which has been released into, and is now a part of, the environment.

  • Primary pollutants

    26 September 2001

    Substances known to be harmful as they are released to the environment.

  • Secondary pollutants

    26 September 2001

    Pollutants such as ozone, peroxyacetyl nitrate (PAN), and other compounds formed when nitrogen oxides and hydrocarbons react in the presence of sunlight.

  • Smog

    26 September 2001

    Originally a combination of smoke and fog, now used to describe other mixtures of air pollutants, especially ozone and other compounds formed when strong sunlight acts on a mixture of nitrogen oxides and volatile organic compounds from motor vehicle exhaust.

  • Solar thermal energy

    26 September 2001

    Energy produced by using the sun's rays to heat a gas or liquid that then performs useful work, such as powering an electrical generator. Electricity from solar thermal power plants is now nearly competitive in cost with electricity from conventinal fossil-fuel power plants.

  • Zero-discharge technology

    26 September 2001

    Technology that comprises industrial processes designed to prevent the release of any pollutant harmful to the environment (e.g., recovery of solvents, cleaning rinses, and other chemicals used in manufacturing by collecting them and removing dissolved and suspended materials so the liquids can be reused.

  • Environmental Impact Assessment

    9 August 2001

    A process which predicts the magnitude and importance of effects of a proposed activity on the environment, and on human health, and establishes conditions under which the activity may be undertaken. The result of the process may prevent the activity from proceeding if the potential effects are unacceptable.

  • Hazardous waste

    9 August 2001

    A class of waste materials that poses immediate or long-term risks to human health or the environment and requires special handling for detoxification or safe disposal. Both industrial and household wastes include hazardous materials.

  • Heavy metals

    9 August 2001

    Elements such as copper, lead, cadmium, mercury, and other toxic metals used in industrial processes and often released as both air and water pollutants. They may accumulate to hazardous concentrations in sediments and sludge.