Chemicals in environment

Martin, D. Search for toxic chemicals in environment gets a slow start, is proving difficult and expensive. 

Published by the Department of Health, U.K. Covers chemicals in environment, pesticides, industrial chemicals, air and water pollution. Citations taken from journals, conference proceedings, government documents, grey literature etc. received by the Department of Health Library, London. Covers publications 1984 to date. 

Ana.lytica.1 Methods. Since 1984, dramatic technical advances have been made in the analysis of trace organic chemicals in the environment. Indeed, these advances have been largely responsible for the increased pubUc and governmental awareness of the wide distribution of herbicides in the environment. The abiUty to detect herbicides at ppb and ppt levels has resulted in the discovery of trace herbicide residues in many unexpected and unwanted areas. The realization that herbicides are being transported throughout the environment, albeit at extremely low levels, has caused much pubUc and governmental concern. However, the pubUc health implications remain unclear. 

M. Vandedaan and co-workers. Immunoassaysfor Trace Chemical Analysis Monitoring Toxic Chemicals in Humans, Food and the Environment, ACS Symposium Series 451, American Chemical Society, Washington, D.C., 1991. 

Corrosion by Various Chemicals and Environments. In general, the rate of corrosion of magnesium ia aqueous solutions is strongly iafluenced by the hydrogen ion [12408-02-5] concentration or pH. In this respect, magnesium is considered to be opposite ia character to aluminum. Aluminum is resistant to weak acids but attacked by strong alkaUes, while magnesium is resistant to alkaUes but is attacked by acids that do not promote the formation of iasoluble films. 

J. C. BuzzeU, Jr. and co-workers. Behavior of Organic Chemicals in the Mquatic Environment, Part III—Behavior in Merobic Treatment Systems (Activated Sludge), Association of Manufacturing Chemists, Washington, D.C., 1969, pp. 26—31. 

In the chemical industry, titanium is used in heat-exchanger tubing for salt production, in the production of ethylene glycol, ethylene oxide, propylene oxide, and terephthaHc acid, and in industrial wastewater treatment. Titanium is used in environments of aqueous chloride salts, eg, ZnCl2, NH4CI, CaCl2, and MgCl2 chlorine gas chlorinated hydrocarbons and nitric acid. 

The second approach, changing the environment, is a widely used, practical method of preventing corrosion. In aqueous systems, there are three ways to effect a change in environment to inhibit corrosion (/) form a protective film of calcium carbonate on the metal surface using the natural calcium and alkalinity in the water, (2) remove the corrosive oxygen from the water, either by mechanical or chemical deaeration, and (3) add corrosion inhibitors. 

Laws and regulations on the use of chemicals in aquaculture vary by country and serve to ensure safe and effective use and protection of humans and the environment. Regulations and therapeutants or other chemicals that are approved or allowed for use in the United States, Canada, Europe, and Japan are presented below. 

Fuels, Lubricants, and Transmission Fluids. Polyol esters of neopentanoic acid have been used as high vacuum pumping hquids that are stable in chemically aggressive environments (70). Esters such as 6- -ani1inophenoxy)hexy1 pivalate are used as antioxidants for synthetic ester lubricants (71). PivaUc anhydride [1538-75-6] has been claimed as an antiknock additive for gasoline (72). 

A number of analytical methods have been developed for the determination of chlorotoluene mixtures by gas chromatography. These are used for determinations in environments such as air near industry (62) and soil (63). Liquid crystal stationary columns are more effective in separating m- and chlorotoluene than conventional columns (64). Prepacked columns are commercially available. ZeoHtes have been examined extensively as a means to separate chlorotoluene mixtures (see Molecularsieves). For example, a Y-type 2eohte containing sodium and copper has been used to separate y -chlorotoluene from its isomers by selective absorption (65). The presence of ben2ylic impurities in chlorotoluenes is determined by standard methods for hydroly2able chlorine. Proton (66) and carbon-13 chemical shifts, characteristic in absorption bands, and principal mass spectral peaks are available along with sources of reference spectra (67). 

The introduction of surfactant products into the environment, after use by consumers or as part of waste disposed during manufacture, is regulated by the Clean Water Act, the Clean Air Act, and the Resource Conservation and Recovery Act. In this respect, surfactants are subject to the same regulations as chemicals in general. There are, however, two areas of specific relevance to surfactants and detergent products, ie, biodegradabiUty and eutrophication. 

The Toxic Substances Control Act (TSCA) was enacted in 1976 to identify and control toxic chemical ha2ards to human health and the environment. One of the main provisions of TSCA was to estabUsh and maintain an inventory of all chemicals in commerce in the United States for the purpose of regulating any of the chemicals that might pose an unreasonable risk to human health or the environment. An initial inventory of chemicals was estabhshed by requiring companies to report to the United States Environmental Protection Agency (USEPA) all substances that were imported, manufactured, processed, distributed, or disposed of in the United States. Over 50,000 chemical substances were reported. PoUowing this initial inventory, introduction of all new chemical substances requires a Premanufacturing Notification (PMN) process. To be included in the PMN are the identity of the new chemical, the estimated first year and maximum production volume, manufacture and process information, a description of proposed use, potential release to the environment, possible human exposure to the new substance, and any health or environmental test data available at the time of submission. In the 10 years that TSCA has been in effect, the USEPA has received over 10,000 PMNs and up to 10% of the submissions each year are for dyes (382)... 

Also, the electronic control-valve device s level of immunity to, and emission of, electromagnetic interference (EMI) can be an issue in the chemical-valve environment. EMI requirements for the control-valve devices are presently mandatory in the European Community but voluntary in the United States, Japan, and the rest of the world. International Electrotechnical Commission (lEC) SOI, Parts I through 4, Electromagnetic Compatibihty for Industrial Process Measurement and Control Equipment, defines tests and requirements for control-device immunity. Immunity and emission standards are addressed in CENELEC (European Committee for Electrotechnical Standardization) EN 50 081-1 1992, EN 50 081-2 1993, EN 50 082-1 1992, and prEN 50 082-2 1994. 

Lead and Alloys Chemical leads of 99.9+ percent purity are used primarily in the chemical industiy in environments that form thin, insoluble, and self-repairable protective films, for example, salts such as sulfates, carbonates, or phosphates. More soluble films such as nitrates, acetates, or chlorides offer little protection. 

J. Oehlmann, U. Sehulte-Oehlmann, E. Stroben, B. Bauer, C. Bettin and P. Fiorni, in Endocrinologically Active Chemicals in the Environment, Umweltbundesamt, Berlin, 1996, pp. 111-118. 

In a 1996 review, the Committee of Toxicity of Chemicals in Food, Consumer Products and the Environment (COT) estimated the intake of isoflavones from soya-milk to be approximately 4 mg/kg/day over the first 4 months of life. This is greater than that associated with hormonal effects in premenopausal women, but the COT nonetheless supported the existing Department of Health s advice that... 

For coating optical devices for use in chemically aggressive environments. 

Chemicals are ubiquitous as air, carbohydrates, enzymes, lipids, minerals, proteins, vitamins, water, and wood. Naturally occurring chemicals are supplemented by man-made substances. There are about 70000 chemicals in use with another 500-1000 added each year. Their properties have been harnessed to enhance the quality of life, e.g. cosmetics, detergents, energy fuels, explosives, fertilizers, foods and drinks, glass, metals, paints, paper, pesticides, pharmaceuticals, plastics, rubber, solvents, textiles thus chemicals are found in virtually all workplaces. Besides the benefits, chemicals also pose dangers to man and the environment. For example ... 

Richardson, M.L. (ed.) (1988) Risk Assessment of Chemicals in the Environment, The Royal Society of Chemistry, London. 

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