| LC control no. | sh 85059851 |
|---|---|
| Topical heading | Heavy metals |
| Variant(s) | Toxic metals |
| See also | subdivision Heavy metal content under individual animals and groups of animals and individual plants and groups of plants, e.g., Fishes--Heavy metal content; Corn--Heavy metal content Metals Poisons |
| Found in | Wikipedia, Sept. 24, 2012: Heavy metal (chemistry) (A heavy metal is a member of a loosely defined subset of elements that exhibit metallic properties. It mainly includes the transition metals, some metalloids, lanthanides, and actinides. Many different definitions have been proposed--some based on density, some on atomic number or atomic weight, and some on chemical properties or toxicity. The term heavy metal has been called a "misinterpretation" in an IUPAC technical report due to the contradictory definitions and its lack of a "coherent scientific basis". There is an alternative term toxic metal, for which no consensus of exact definition exists either. As discussed below, depending on context, heavy metal can include elements lighter than carbon and can exclude some of the heaviest metals. Heavy metals occur naturally in the ecosystem with large variations in concentration. In modern times, anthropogenic sources of heavy metals, i.e. pollution, have been introduced to the ecosystem. Waste-derived fuels are especially prone to contain heavy metals, so heavy metals are a concern in consideration of waste as fuel.) Toxic metal (Toxic metals are metals that form poisonous soluble compounds and have no biological role, i.e. are not essential minerals, or are in the wrong form. Often heavy metals are thought as synonymous, but lighter metals also have toxicity, such as beryllium, and not all heavy metals are particularly toxic, and some are essential, such as iron. The definition may also include trace elements when considered in abnormally high, toxic doses. A difference is that there is no beneficial dose for a toxic metal with no biological role) The American heritage dictionary of the English language, ©2000, via TheFreeDictionary website, Sept. 24, 2012 (heavy metal: 1. A metal with a specific gravity greater than about 5.0, especially one that is poisonous, such as lead or mercury) Collins English dictionary -- complete and unabridged, ©2003, via TheFreeDictionary website, Sept. 24, 2012 (heavy metal: 2. (Chemistry) a metal with a high specific gravity) Dictionary.com, Sept. 24, 2012 (heavy metal 1. any metal with a specific gravity of 5.0 or greater, especially one that is toxic to organisms, as lead, mercury, copper, and cadmium) Duffus, J.H. "Heavy metals": a meaningless term, via International Union of Pure and Applied Chemistry website, Sept. 24, 2012 (the term "heavy metals" has been used increasingly in various publications and in legislation related to chemical hazards and the safe use of chemicals. It is often used as a group name for metals and semimetals (metalloids) that have been associated with contamination and potential toxicity or ecotoxicity. We have no consistent basis for defining the term); there is no chemical basis for deciding which metals should be included in this category (heavy metals)) Ott, A.G. Fish monitoring study, Red Dog Mine in the Wulik River drainage, emphasis on Dolly Varden (Salvelinus malma), 1992 progress report, 1993: p. 7 (study to document heavy metal concentrations of select fish tissues; heavy metal concentrations (Zn, Cu, Pb, Al, and Cd) in gill, liver, muscle, and kidney tissue of adult Dolly Varden (Salvelinus malma)) p. 12 (Dolly Varden tissue heavy metals concentrations) OCLC, July 10, 2018 (in titles: heavy metal content in some Malaysian marine and freshwater fishes; heavy metal content of some fresh water fishes in British Columbia; heavy metal content and biotransformation enzymes in two fish species; heavy metal content in marine bivalves; heavy metal content in liver and feathers of seabirds; heavy metal content in freshly commercialized molluscs; heavy metal content of South Platte River invertebrates) |
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