Contaminants in drinking water

Maximum Contaminant Level Goal (MCLG) - The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety and are non-enforceable public health goals. 

Treatment Technique - A required process intended to reduce the level of a contaminant in drinking water. 

Disinfectants Disinfection Byproducts MCLG (mg/L) MCL or TT (mg/L) Potential Health Effects from Ingestion of Water Sources of Contaminant in Drinking Water... 

Human health based guidance levels (HBGLS)for ingestion of contaminents in drinking water Oral HBGL 42 ug/L Arizona Department of Health Services 1999... 

The SDWA was enacted in 1974, with amendments promulgated in 1986 and 1996. The SDWA expanded the role of the federal government to establish national standards for the levels of contaminants in drinking water, creating state programs to... 

An analysis of potential human exposure to contaminants in drinking water and foods was conducted in Ontario, Canada, in 1980. Mirex was detected only in edible fish taken from Toronto Harbor on Lake Ontario. The average mirex concentrations were 0.001 mg/kg (ppm) wet weight for white sucker, 0.01 mg/kg wet weight for rainbow trout, and 0.033 mg/kg wet weight for northern pike. Estimated human exposure levels, based on an average fish consumption of 0.53 kg/year for each fish species, were 0.0005 for white sucker, 0.0005 for rainbow trout, and 0.017 mg/year for northern pike, respectively (Davies 1990). 

Hunsinger RB. 1987. Organic contaminants in drinking water what where when and how. In Huck PM, Toft P, eds. Treatment of Drinking Water For Organic Contaminants, Second National Conference, Edmonton, Alberta, April 7-8, 1986, 29-44. 

The Safe Drinking Water Act (SDWA), enacted in 1974 to assure high-quality water supplies through public water system. The act is truly the first federal intervention to set the limits of contaminants in drinking water. The 1986 amendments came two years after passage of the Hazardous and Solid Waste Amendments (HSWA) or the RCRA amendments of 1984. As a result, certain statutory provisions were added to these 1986 amendments to reflect the changes made in the underground injection control (UIC) systems. 

Accuracy in the laboratory is obviously an important issue. If the analysis results reported by a laboratory are not accurate, everything a company or government agency strives for, the entire TQM system, may be in jeopardy. If the customer discovers the error, especially through painful means, the trust the public has placed in the entire enterprise is lost. For example, if a baby dies due to nitrate contamination in drinking water that a city s health department had determined to be safe, that department, indeed the entire city government, is liable. In this "worst-case scenario," some employees would likely lose their jobs and perhaps even be brought to justice in a court of law. 

This kind of measurement is sometimes called a mass-mass percent solution because one mass is divided by another. Very dilute concentrations (as in the concentration of a contaminant in drinking water) are sometimes expressed as a special mass percent called parts per million (ppm) or parts per billion (ppb). In these metrics, the mass of the solute is divided by the total mass of the solution, and the resulting fraction is multiplied by 10 (ppm) or by 10 (ppb). 

Vang, O., Wallin, H., Doehmer, J. Autrup, H. (1993) Cytochrome P450-mediated metabolism of tumour promoters modifies the inhibition of intercellular cormnunication a modified assay for tumour promotion. Carcinogenesis, 14, 2365-2371 Verschueren, K. (1996) Handbook of Environmental Data on Organic Chemicals, 3rd Ed., New York, Van Nostrand Reinhold, pp. 866-873 Vitali, M., Leoni, V, Chiavarini, S. Cremisini, C. (1993) Determination of 2-ethyl-l-hexanol as contaminant in drinking water. J. Assoc, off anal. Chem. int., 76, 1133-1137... 

Use of Large-Volume Resin Cartridges for the Determination of Organic Contaminants in Drinking Water Derived from the Great Lakes... 

Fluorescein (703) (Acid Yellow 73 C.I. 45350) is possibly the best known xanthene dye. The sodium salt is soluble in water to which it imparts an intense yellow-green fluorescence, detectable even at a dilution of 0.02 p.p.m. under UV irradiation. This property leads to the use of fluorescein as a location marker for aircraft lost at sea, as a tracer for the detection of a source of contamination in drinking water, and in a number of related situations. The use of fluorescein to detect abrasions of the cornea is also based on its fluorescence. 

International network organized by the IDRC (International Development Research Centre), in collaboration with the National Water Research Institute and the Saint-Lawrence Centre of Environment Canada, to undertake bioanalytical intercalibration exercises with participating laboratories from eight different countries (Argentina, Canada, Chile, Colombia, Costa Rica, India, Mexico and Ukraine). The battery of simple, affordable and robust tests was initially selected to detect the toxic potential of chemical contaminants in drinking water and freshwater sources. Volume 2(7). 

Pharmacologically based pharmacokinetic (PBPK) models have also been incorporated into the assessment of responses to mixtures of some substances where interactions may occur. This was suggested for application in assessing human health risks of contaminants in drinking water (Krishnan et al. 1997) on the basis that most interactions between organic substances occur as a result of induction or inhibition of metabolism. This has been applied in predicting the maximal likely interaction in mixtures of chlorinated and nonchlorinated hydrocarbons (Haddad et al. 2000) and aromatic petroleum hydrocarbons (Haddad et al. 1999). Metabolic and other data are required for PBPK models, and, as these may only be available for a few organisms in the environment, they are not yet widely used for extrapolation. 

AZ Dept Health Services. 1999. Health based guidance levels for the ingestion of contaminants in drinking water. Arizona Department of Health Services, Office of Environmental Health. http //www.hs.state.az.us/. 

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