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Glossary
08/2008 abiotic not caused by living organisms aerobic occurring in, or involving, the presence of oxygen anaerobic occurring in, or involving, the absence of oxygen anthropogenic relating to environmental changes resulting from the presence of activities or humans aortic relating to the main vessel of the heart AOX Adsorbable Organic Halogens. This is the result of a standard analytical procedure for the determination of the sum of the halogens chlorine, bromine and iodine. The AOX value is expressed in equivalent chlorine and is sometimes called a "group parameter" or "sum parameter". It gives no information on the nature of the halogen compounds present in the sample. See also "TOX" aquifer the section of the subsoil where groundwater accumulates atherosclerotic relating to the deposition of lipids (fats) with the proliferation of connective tissue in the inner walls of the arteries auxin a plant hormone able to control growth bioavailability existence of a substance in a physical and chemical state which can be taken up by living organisms biogenic produced by living organisms biotic caused by living organisms congeners as used here, this term refers to the members of the polychlorinated dioxin and dibenzofuran families of compounds, including molecules having different degrees of chlorination, as well as isomers of those molecules having the same degree of chlorination cytotoxic relating to an agent that is toxic to cells fluvial related to or produced by streams or rivers fulvic acids complex acids derived from humus, soluble in both acidic and basic solutions halogenation a reaction involving introduction of a halogen into a chemical structure halogens a family of chemical elements including fluorine, chlorine, bromine and iodine haloperoxidases enzymes capable of catalyzing the conversion of halides (e.g. chlorides) into chemically active forms of halogens, and/or of halogenating organic compounds humic acids complex acids derived from humus, insoluble in acidic solutions, but soluble at high pHs humification the process by which plant or animal matter is converted into humus humus complex material resulting from partial decomposition of plant or animal matter and forming the organic portion of soil infiltrating water precipitation seeping down from the land surface to the groundwater lacustrine related to or produced by lakes macrophyte a macroscopic plant, usually in the aquatic environment microalgae phytoplankton (as opposed to macroalgae or seaweed) NADH the reduced form of nicotinamide adenine dinucleotide, a co-enzyme involved in biological oxidation-reduction processes organochlorines chemical compounds containing at least one carbon-chlorine bond organohalogens chemical compounds containing at least one carbon-halogen bond phagocytic relating to a cell that engulfs and destroys foreign matter suboxic zone that part of a water body lying between the fully oxygenated zone (close to the surface) and deeper waters totally deprived of oxygen; it contains low concentrations of both oxygen and reduced species such as hydrogen sulphide TOX Total Organic Halogens. As applied by ASTM (USA), the term TOX refers to the result of a standard analytical procedure (comparable to that for AOX - see above) for the determination of the sum of the halogens chlorine, bromine and iodine in unfiltered and unpurged water samples. The term TOX is also used to express total organic halogens in solid samples (soils and sediments) troposphere the lowest 10-20 km of the atmosphere, between the earth’s surface and the tropopause. |