Environmental contaminant

The elements listed in the table of Figure 15.2 are of importance as environmental contaminants, and their analysis in soils, water, seawater, foodstuffs and for forensic purposes is performed routinely. For these reasons, methods have been sought to analyze samples of these elements quickly and easily without significant prepreparation. One way to unlock these elements from their compounds or salts, in which form they are usually found, is to reduce them to their volatile hydrides through the use of acid and sodium tetrahydroborate (sodium borohydride), as shown in Equation 15.1 for sodium arsenite. 

Hites, R.A., Handbook of Mass Spectra of Environmental Contaminants, Lewis Publishers, Boca Raton, FL, 1992. 

L. N. Davis, P. R. Durkin, P. H. Howard, andj. Saxena, Investigation of Selected Potential Environmental Contaminants Jicrylamides-, EPA Report No. 560/2-76-008,1976. 

A comprehensive search (295) of the STORET water quaUty database, maintained by the U.S. EPA Office of Water, is used to evaluate the potential water quaUty implications of various herbicides. This database contains information on contamination of surface water (SW) and groundwater (GW) suppUes. The data are provided to give a general impression of the occurrence of a given herbicide in SW and GW (269). The U.S. EPA scheme for categorizing a chemical s carcinogenic potential is used for herbicides for which healthy advisory information (HA) is available. The U.S. EPA is continually issuing HAs for various environmental contaminants HAs available in Reference 269 were used in preparation of this article. 

DDT at 0.25—0.75% and dieldrin at 0.05% appHed during dry cleaning or by spraying fabrics with aqueous emulsions of equivalent strength were formerly used extensively as semipermanent fabric protectants. However, these are no longer used because of problems of environmental contamination. 

Enzymes for Extreme Conditions. The possibihty of using enzymes from extremophiles, which thrive in oil wells, hot temperatures, freezing conditions, etc, is being explored for the removal of environmental contaminants and survival at extreme temperatures (see Wastes, HAZARDOUS WASTE TREATlffiNT BlORETffiDIATION (SuPPLET NT)). 

Unfortunately, there is a significant disadvantage resulting from appHcation of insect-resist agents from dyebaths it is impossible to ensure 100% exhaustion (transfer of pesticide from dyebath to fiber) and as a result, there is inevitably some environmental contamination. The extent of concern with this release of insect-resist agent depends on the spectmm of activity of the agent. If it is a broad-spectmm insecticide, especially one with reasonable persistence and lipophilic character, it is Hable to be reasonably toxic to aquatic insects and invertebrates, especially in certain environmental locations where... 

Historically, polychloriaated biphenyls (PCBs) and to a lesser extent polychlorinated terphenyls (PCTs) were the most important derivatives of the respective polyphenyls. When they came to be recognized as serious environmental contaminants, production ceased in the early 1970s. These products are now of significance primarily because of thek environmental aftereffects (62). Much environmental research and governmental regulations stem therefrom... 

W. M. Meylan and P. H. Howard, Chemical Market Input] Ouput Analysis of Selected Chemical Substances to Assess Sources of Environmental Contamination ... 

Selection of Solvent When choice is possible, preference is given to liquids with high solubilities for the solute a high solubility reduces the amount of solvent to be circulated. The solvent should be relatively nonvolatile, inexpensive, noncorrosive, stable, nonviscous, nonfoaming, and preferably nonflammable. Since the exit gas normally leaves saturated with solvent, solvent loss can be costly and may present environmental contamination problems. Thus, low-cost solvents may be chosen over more expensive ones of higher solubility or lower volatility. 

One of trends of development of thin-layer chromatography implies that replacement of aqueous-organic eluents by micellar surfactants solution. This is reduces the toxicity, flammability, environmental contamination and cost of the mobile phases, reduce sample prepar ation in some cases. 

Human exposure to environmental contaminants has been investigated through the analysis of adipose tissue, breast milk, blood and the monitoring of faecal and urinary excretion levels. However, while levels of persistent contaminants in human milk, for example, are extensively monitored, very little is known about foetal exposure to xenobiotics because the concentrations of persistent compounds in blood and trans-placental transmission are less well studied. Also, more information is needed in general about the behaviour of endocrine disruptive compounds (and their metabolites) in vivo, for example the way they bind to blood plasma proteins. 

S. J. de Mora(ed.), Tributyltin Case Study of an Environmental Contaminant, Cambridge University Press, Cambridge, 1996. 

In recent years, environmental contamination by lead, cadmium, and mercury has been repeatedly observed and has given rise to partly exaggerated reports. 

Toxic and complex environmental contaminants are not created during the destruction of the materials. 

Electronic version of Sax s Dangerous Properties of Industrial Materials, 9th ed., Hawley s Condensed Chemical Dictionaiy Prager s Environmental Contaminant Reference Databook, Vols, I, II III Verschueren s Handbook of Environmental Data on Organic Chemicals, 3rd ed. and Pohan-ish and Greene s Hazardous Materials Handbook, on CD-ROM, John Wiley and Sons, New York, NY, 1998. 

The process emits environmental contaminants or pollutants into the aunosphere... 

Dioxins are prominent members of the class of polychlorinated hydrocarbons that also includes diben-zofuran, biphenyls and others. Dioxins are highly toxic environmental contaminants. Like others small planar xenobiotics, some dioxins bind with high affinity to the arylhydrocarbon (Ah) receptor. Dioxins activate the receptor over a long time period, but are themselves poor substrates for the enzymes which are induced via the Ah-receptor. These properties of the dioxins and related xenobiotics may be important for the toxicity of these compounds. Dioxins like 2,3,7,8-tetrachloro-p-dibenzodioxin can cause persistent dermatosis, like chloracne and may have other neurotoxic, immunotoxic and carcinogenic effects. 

Di- and mono-esters of phthalic acid, an ortho-dicarboxylic acid derivative of benzene. These compounds are widely used as industrial plasticizers to coat polyvinylchloride surfaces of plastics used in food packaging and medical devices (iv drip bags, blood storage bags, etc.) and are common environmental contaminants. Several phthalate mono-esters are peroxisome proliferator chemicals and can activate the peroxisome proliferator-activated receptor PPAR. 

Conduct exploratory and engineering activities in the methods and technology of manufacture as applied to assigned commodities and their components, materials and ancillary equipment except projectile metal parts which are the responsibility of Frank ford Arsenal, and specified elements of chemical items which are the re-sponsibility of Edge wood Arsenal. This is to include support of plant/facilities modernization within ARMCOM, abatement of environmental contamination caused by manufacturing processes and exploitation of automation techniques... 

Capodaglio, G., Scarponi, G., P. Cescon. Lead contamination of seawaters with different anthropic influence. Ill International Conference "Environmental Contamination", Venice, Sept. 1988, pp. 505-407. 

The use of aromatic brominated compounds as flame retardants has been a potential source of environmental contamination. Incomplete incineration of these compounds and wastes (plastics, textiles, oils etc...) containing brominated flame retardants caused formation of brominated/chlorinated dibenzodioxines (PBDDs/ PCDDs) and dibenzofurans (PCDFs/PBDFs) (refs. 1 - 4). 

Zuccato E, Castiglioni S, Bagnati R, Chiabrando C, Grassi P, Fanelli R (2008) Illicit drugs, a novel group of environmental contaminants. Water Res 42(4-5) 961-968... 

Noda T, Nakamura T, Shimizu M, Yamano T, Merita S (1992b) Critical gestational day of teratogenesis by di-normal-butyltin diacetate in rats. Bulletin of Environmental Contamination and Toxicology. 49(5) 715-722. 

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