Predicting the uncertainties in risk assessment

Journal Article · Tue Oct 01 04:00:00 EDT 1991 · Environmental Science and Technology; (United States)

DOI:https://doi.org/10.1021/es00022a002· OSTI ID:5238362

McKone, T E; Bogen, K T ^[1]

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1. Lawrence Livermore National Lab., CA (United States)

Reducing uncertainty in assessing the risk of environmental contaminants is important to state and federal regulatory agencies and to nonregulatory agencies that work for environmental health and safety. In practice risk often is characterized as a product of four factors: source term, exposure factors, fraction absorbed, and toxic potency. Actual risk can be more complex. A case study based on the volatile organic chemical tetrachloroethylene (perchloroethylene, PCE) in California water supplies is the basis for this analysis of risk assessment. The analysis is divided into five steps: a consideration of the magnitude and variability of PCE concentrations available in large public water supplies in California, characterization of pathway exposure factors (PEFs) for groundwater exposures and estimation of the uncertainty for each PEF, examination of models that describe uptake and metabolism to estimate the relation between exposure and metabolized dose, consideration of the carcinogenic potency of the metabolized PCE dose, and finally, a combination of the results to estimate the overall magnitude and uncertainty of increased risk to an individual selected at random from the exposed population and an exploration of the important contributions to overall uncertainty. A mathematical model of risk is obtained from this case study. Uncertainties in analysis should be considered carefully by risk managers and strategies adopted to reduce that uncertainty.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5238362
• Journal Information: Environmental Science and Technology; (United States), Journal Name: Environmental Science and Technology; (United States) Vol. 25:10; ISSN ESTHA; ISSN 0013-936X
• Country of Publication: United States
• Language: English

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