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U.S. Department of Energy
Office of Scientific and Technical Information

Computer assisted, risk-based screening of a mixture of drinking water chemicals

Conference · · Trace Subst. Environ. Health; (United States)
OSTI ID:5881719

During 1987, EPA Region III sampled raw and treated drinking water at ten locations in Virginia and Pennsylvania to estimate risks to human health associated with water use. Composite samples were taken from water supply intakes in the Roanoke River basin and the lower Susquehanna River in early spring, late spring, and mid-summer, periods in which temperature, flow, and pesticide inputs varied widely. Samples were analyzed for 187 contaminants, including metals, volatile organic compounds, pesticides, and polynuclear aromatic compounds. One hundred three substances were detected in at least one water sample. Upper bound lifetime carcinogenic risks and systemic hazard indexes were calculated by computer for each chemical in each sample, assuming ingestion of 2 1 d/sup /minus/1/, 70-kg body weight, and 70-yr lifetime. These carcinogenic risks and hazard indexes were summed to estimate total risk and hazard index for each sample. Sample sums were averaged for each location. Mean upper bound lifetime cancer risk ranged from 8 x 10/sup /minus/5/ to 2 x 10/sup /minus/4/; total systemic hazard index ranged from 0.1 to 0.5. These risk estimates were subject to the following uncertainties: (1) those associated with EPA's use of the linearized multistage low dose extrapolation model for cancer, (2) adjustments for species differences, (3) possible unknown interactions among chemicals, (4) sampling error, and (5) undetected chemicals which may have been present.

Research Organization:
Environmental Protection Agency, Philadelphia, PA (USA)
OSTI ID:
5881719
Report Number(s):
CONF-8805159-
Journal Information:
Trace Subst. Environ. Health; (United States), Journal Name: Trace Subst. Environ. Health; (United States) Vol. 12; ISSN PUMTA
Country of Publication:
United States
Language:
English