{"term":{"code":"769","name":"contamination and pollution","parent":"1174","scope":"Introduction of harmful substances into the environment by human action or natural processes."},"uf":[{"name":"water pollution","usewith":{"code":"1308","name":"water resources","parent":"777","scope":"Stocks of water, the liquid derived from precipitation. A constituent of living matter and necessity for all life, it covers a large proportion of the earth's surface."}},{"name":"soil pollution","usewith":{"code":"1080","name":"soil resources","parent":"777","scope":"Natural resources of unconsolidated fragmented rock, humus, and mineral matter that cover the surface of the earth."}},{"name":"natural contaminants","usewith":false},{"name":"pollution","usewith":false},{"name":"air pollution","usewith":{"code":"65","name":"atmospheric composition","parent":"67","scope":"Components of the mass of gases that surrounds a planet.  The earth's atmosphere consists of nitrogen, oxygen, and small portions of other gases."}},{"name":"effluent","usewith":false},{"name":"outfall","usewith":false}],"bt":[{"code":"1174","name":"topics","parent":"1","scope":"Themes, subjects, and concerns for which USGS information resources are relevant."},{"code":"1","name":"Categories","parent":null,"scope":"Thematic terms for categorizing information resources.  This thesaurus is intended to support finding and understanding scientific information."}],"nt":[{"code":"1363","name":"nonpoint-source pollution","parent":"769","scope":"Contamination of the environment from sources spread widely across an area, not from a small number of identifiable locations."},{"code":"1723","name":"industrial pollution","parent":"769","scope":"Introduction of harmful substances into the environment by manufacturing, power generation, mining, or material processing."},{"code":"879","name":"pesticide and herbicide contamination","parent":"769","scope":"Pollution resulting from chemical agents applied to crops, rights of way, lawns, or residences to control weeds, insects, fungi, nematodes, rodents or other pests (pesticides) or kill undesirable plants (herbicides)."},{"code":"1180","name":"toxic radionuclide contamination","parent":"769","scope":"Introduction into the environment of unstable isotopes of elements that undergo radioactive decay, emitting radiation that is harmful to organisms."},{"code":"1181","name":"toxic trace element contamination","parent":"769","scope":"Introduction into the environment of elements (such as arsenic, cadmium, lead, and mercury) which have a deleterious effect on living organisms when found naturally in only minor amounts (concentrations less than 1.0 milligram per liter) in water or sediment."},{"code":"1693","name":"pharmaceutical contamination","parent":"769","scope":"Unintentional release of pharmaceutical compounds into the environment; work focuses on the effects of these compounds on organisms and water resources."}],"rt":[{"code":"320","name":"ecotoxicology","parent":"650","scope":"Scientific study of causes, dispersal, and effects of contaminants on the environment."},{"code":"531","name":"hazards","parent":"1174","scope":"Potential dangers from both natural processes (e.g., earthquakes, floods, and climate change) and human impacts on the environment."},{"code":"548","name":"human impacts","parent":"1174","scope":"The effects, intentional or unintentional, beneficial or harmful, direct or indirect, which human activities have upon the environment and living things."},{"code":"1293","name":"waste treatment and disposal","parent":"548","scope":"The chemical and physical methods to recycle or dispose of materials which, without treatment, are deemed to have no further value or are too contaminated to be used."},{"code":"1306","name":"water quality","parent":"1174","scope":"The chemical, physical, and biological characteristics of water, usually in respect to its suitability for a particular purpose."}]}