Chloroform in drinking water

Jorgenson TA, Meierhenry EF, Rushbrook CJ, et al. 1985. Carcinogenicity of chloroform in drinking water to male Osbome-Mendel rats and female B6C3Fj mice. Fundam Appl Toxicol 5 760-769. 

The EPA sets rules for the amount of chloroform allowed in water. The EPA limit for total trihalomethanes, a class of chemicals that includes chloroform, in drinking water is 100 micrograms per liter (pg/L, 1 pg/L = 1 ppb in water). Furthermore, EPA requires that spills of 10 pounds or more of chloroform into the environment be reported to the National Response Center. 

Pereira (1994) provided further evidence of the effect of dosing method (gavage versus drinking water) and vehicle (com oil versus water) on hepatic cell proliferation in female B6C3Fi mice. Animals received either 263 mg/kg/day chloroform by gavage in com oil or 1,800 ppm chloroform in drinking water,... 

This study was designed to identify a relationship between the magnitude and duration of chloroform-induced histopathologic and proliferative responses for female mice dosed with chloroform in the drinking water vs those dosed in com oil via gavage. Authors placed 0, 60,200,400,900, or 1,800 ppm of chloroform in drinking water however, due to decreased water intake, the authors calculation of consumed chloroform was 0,16,26,... 

Jorgenson, T. A. Meierhenry, E. F. Rushbrook, C. A. Bull, R. J. Robinson, M. Whitmice, C. E. Carcinogenicity of Chloroform in Drinking Water to Male Osborne-Mendel Rats and Female B6C3F1 Mice Draft report, SRI International Menlo Park, CA, 1984. 

Hammerstrand, K. Chloroform in Drinking Water, Varian Instrument Application, 10, 22 (1976). 

Many chemical risks such as those of chloroform in drinking water, are calculated, not measured - that is, they are based not only on scientific data, but also on various sets of assumptions and extrapolation models that, while scientifically plausible (they fall within the bounds of acceptable biological theory), have not been subjected to empirical study and verification. Indeed, the results of most risk assessments - whether expressed as an estimate of extra cancer risk or an ADI - are scientific hypotheses that are not generally testable with any practicable epidemiological method. There is, for example, no practical means to test whether chloroform residues in chlorinated drinking water increase lifetime cancer risk in humans by 8 in 1000000, as hypothesized above. The tools of epidemiology are enormously strained, indeed, when called upon to detect the relatively low risks associated with most environmental chemicals. Without such a test, these risks remain unverified. 

HC (2004a). Chloroform in drinking water. H. C. Federal-Provincial-Territorial Committee on Drinking Water, Ottawa, Ontario. 

Chloroform in drinking water may be aerobically biodegraded to carbon dioxide (Speitel et al. 1989). Bacterial cultures from contaminated sites produced efficient degradation of chlorinated hydrocarbons in laboratory-scale continuous-flow reactors (Kaestner 1989). Woods and coworkers... 

ABSTRACT In the definition of safety states of water supply system the quality of drinking water plays an important role. Especially, trihalomethanes as disinfection by-products have to be taken into consideration, because they are dangerous for consumer s health and their concentration usually increase in water distribution subsystem. In this paper the method of determining the thresholds for water quality states (included in the comprehensive method of safety analysis) is presented. The states are based on chloroform because its share in total trihalomethanes is about 80%. Using the tools of mathematical statistics the relationships between chloroform and other quality and operational parameters of drinking water were analyzed and applied to an estimation of quality states. Additionally, the estimation of quality states was based on chloroform in drinking water flowing out from water treatment plant to water pipe network. The study was based on data obtained from the real water supply system. 

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