Contamination of bodies of water (such as LAKES; RIVERS; SEAS; and GROUNDWATER.)
Water Pollution, Chemical
A rating of a body of water based on measurable physical, chemical, and biological characteristics.
Water Pollutants, Chemical
Water containing no significant amounts of salts, such as water from RIVERS and LAKES.
The presence of bacteria, viruses, and fungi in water. This term is not restricted to pathogenic organisms.
Any substance in the air which could, if present in high enough concentration, harm humans, animals, vegetation or material. Substances include GASES; PARTICULATE MATTER; and volatile ORGANIC CHEMICALS.
Nitrogen oxide (NO2). A highly poisonous gas. Exposure produces inflammation of lungs that may only cause slight pain or pass unnoticed, but resulting edema several days later may cause death. (From Merck, 11th ed) It is a major atmospheric pollutant that is able to absorb UV light that does not reach the earth's surface.
The exposure to potentially harmful chemical, physical, or biological agents in the environment or to environmental factors that may include ionizing radiation, pathogenic organisms, or toxic chemicals.
The unstable triatomic form of oxygen, O3. It is a powerful oxidant that is produced for various chemical and industrial uses. Its production is also catalyzed in the ATMOSPHERE by ULTRAVIOLET RAY irradiation of oxygen or other ozone precursors such as VOLATILE ORGANIC COMPOUNDS and NITROGEN OXIDES. About 90% of the ozone in the atmosphere exists in the stratosphere (STRATOSPHERIC OZONE).
Fluids composed mainly of water found within the body.
Any of several processes in which undesirable impurities in water are removed or neutralized; for example, chlorination, filtration, primary treatment, ion exchange, and distillation. It includes treatment of WASTE WATER to provide potable and hygienic water in a controlled or closed environment as well as provision of public drinking water supplies.
Magnesium oxide (MgO). An inorganic compound that occurs in nature as the mineral periclase. In aqueous media combines quickly with water to form magnesium hydroxide. It is used as an antacid and mild laxative and has many nonmedicinal uses.
An amorphous form of carbon prepared from the incomplete combustion of animal or vegetable matter, e.g., wood. The activated form of charcoal is used in the treatment of poisoning. (Grant & Hackh's Chemical Dictionary, 5th ed)
Process of using a rotating machine to generate centrifugal force to separate substances of different densities, remove moisture, or simulate gravitational effects. It employs a large motor-driven apparatus with a long arm, at the end of which human and animal subjects, biological specimens, or equipment can be revolved and rotated at various speeds to study gravitational effects. (From Websters, 10th ed; McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The aggregate business enterprise of manufacturing textiles. (From Random House Unabridged Dictionary, 2d ed)