{"thcode":2,"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":"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":"natural contaminants","usewith":false},{"name":"outfall","usewith":false},{"name":"pollution","usewith":false},{"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":"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."}}],"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":2274,"name":"PFAS","parent":769,"scope":"Per- and polyfluoroalkyl substances (PFAS) are a group of man-made chemical compounds that are an emerging contaminant."},{"code":1723,"name":"industrial pollution","parent":769,"scope":"Introduction of harmful substances into the environment by manufacturing, power generation, mining, or material processing."},{"code":2269,"name":"microplastic contamination","parent":769,"scope":"Plastic particles less than 5 millimeters in diameter that come from a wide variety of sources, found in a variety of forms, including fibers, pellets\/beads, foams, films, fragments, and tire particles, and reach aquatic environments through diverse pathways."},{"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":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":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."},{"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."}],"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."}]}