Risk assessment drinking water

O Flaherty EJ. 1987. Modeling An introduction. In Pharmacokinetics in risk assessment Drinking water and health, vol 8. National Academy of Sciences, Washington, D.C. National Academy Press, 27-3. 

Andersen, M.E. 1987. Tissue dosimetry in risk assessment, or what s the problem here anyway Pp. 8-23 in Pharmacokinetics in Risk Assessment. Drinking Water and Health, Vol. 8. Washington, DC National Academy Press. 

Anonymous. 1989. Pharmacokinetics in risk assessment Drinking water and health. Volume 8. NTIS/PB89-203319. 

Bischoff, K. B. (1987). Physiologically based pharmacokinetic modeling. In Pharmacokinetics in Risk Assessment—Drinking Water and Health, Vol. 8, pp. 36-61. National Academy Press, Washington DC... 

Chen CW, Blancato JN. 1987. Role of pharmacokinetic modeling in risk assessment Perchloroelhylene as an example. In Pharmacokinetics in risk assessment, drinking water and health. Vol. 8. Washington, DC National Academy of Sciences, National Research Council, 369-390. 

This chapter was prepared for the International Agency for Research on Cancer Symposium on Evaluation of Human Health Risks from Drinking Water (December 14, 1984). The opinions expressed in this chapter are those of the author. They do not necessarily reflect the position of the USEPA. The authors perspectives are derived from the assessment activities and interactions with many members of the Criteria and Standards Division and others in the USEPA Office of Drinking Water. These include Larry Anderson, Ambika Bathija, Paul Berger, Richard Cothem, William Coniglio, Penelope Fenner-Crisp,... 

In a catchment area, industries, particularly those involved in extraction, manufacturing and processing, may be important in the assessment of chemical risks of drinking-water because they can be the source of significant contamination. 

The last step in risk assessment consists in expressing the risk in terms of allowable exposure to a contaminated source. Risk is expressed in terms of the concentration of the substance in the environment where human contact occurs. For example, the unit risk in air is risk per mg/m3 whereas the unit risk in drinking water is risk per mg/L. 

P. A. Fenner-Crisp, "Risk Assessment Methods for Pesticides in Food and Drinking Water," Office of Pesticide Programs, U.S. Environmental Protection Agency, presented at the Florida Pesticide Review Council Meeting, July 7, 1989. 

Much of the attention focused on e.xposure assessment has come recently. This is because many of the risk assessments done in tlie past used too many conseix ative assumptions, wliich caused an ovcrcstimation of the actual exposure. Without exposures there are no risks. To experience adverse effects, one must first come into contact with the toxic agent(s). Exposures to chemicals can be via inlialation of air (brcatliing), ingestion of water and food (eating and drinking), or absorption Uu ough the skin. These arc all pathways to the human body. 

Monte Carlo simulation, an iterative technique which derives a range of risk estimates, was incorporated into a trichloroethylene risk assessment using the PBPK model developed by Fisher and Allen (1993). The results of this study (Cronin et al. 1995), which used the kinetics of TCA production and trichloroethylene elimination as the dose metrics relevant to carcinogenic risk, indicated that concentrations of 0.09-1.0 pg/L (men) and 0.29-5.3 pg/L (women) in drinking water correspond to a cancer risk in humans of 1 in 1 million. For inhalation exposure, a similar risk was obtained from intermittent exposure to 0.07-13.3 ppb (men) and 0.16-6.3 ppb (women), or continuous exposure to 0.01-2.6 ppb (men) and 0.03-6.3 ppb (women) (Cronin et al. 1995). 

Bogen KT, Hall LC, Perry L, et al. 1988. Health risk assessment of trichloroethylene (TCE) in California drinking water. Livermore, CA University of California, Lawrence Livermore National Laboratory, Environmental Sciences Division. NTIS No. DE88-005364. 

Cotruvo JA. 1988. Drinking water standards and risk assessment. Regul Toxicol Pharmacol 8 288-299. 

Cyanide contamination creates special public information problems, e.g. it is difficult to explain why cyanide is not included in the current drinking water standards but that aquatic organisms are affected at relatively low cyanide concentration. There is confusion on whether fresh water standards are based on free or complexed cyanides. Fortunately, the provision of a permanent drinking water supply to each affected household removed risk assessment as a major issue. 

The method must be capable of determining all components (a.i. and relevant/major metabolites) that are included in the residue definitions used in the assessment of risk to nontarget organisms. For ground (drinking) water and air, the risk to con-sumers/operators or bystanders must also be considered. 

In the USA, the passage of the Food Quality Protection Act (FQPA) of 1996 has had a significant impact on the determination of residues in drinking water. FQPA requires that all sources of a pesticide be included in its risk assessment, so the potential exposure from drinking water containing a particular pesticide could be a significant... 

Histological changes in the spleen related to diisopropyl methylphosphonate intake were not observed in male or female rats exposed to 1 mg/kg/day of diisopropyl methylphosphonate in their drinking water for 26 weeks (Army 1978). As discussed in Section 2.2.2.1, there is some confusion concerning the concentration units and purity of the diisopropyl methylphosphonate used in the Army (1978) study (EPA 1989), and therefore results from the Army (1978) study are considered inappropriate for human health risk assessment. No changes in spleen weight were noted in male or female mink exposed to... 

The MCL for TCE (5 pg/L) has been determined to be a relevant and appropriate remediation level for the contaminated groundwater at this site because the groundwater is used as a source for drinking water. Based on the site-specific risk assessment, the MCL has been determined to be sufficiently protective as the aquifer remediation goal. 

Schoof, R.A., L.J. Yost, E. Crecelius, K. Irgolic, W. Goessler, H.R. Guo, and H. Greene. 1998. Dietary arsenic intake in Taiwanese districts with elevated arsenic in drinking water. Human Ecol. Risk Assess. 4 117-135. 

---