CONSERVATIVE VERSUS MEAN RISK ASSESSMENTS - IMPLICATIONS FOR SUPERFUND POLICIES

This paper explores how a shift to more central estimates of risk woul d affect EPA decisions to remediate hazardous waste sites in the Super fund program. Analysis of 141 sites indicates that the EPA's use of co nservative parameter values results in risk estimates that are 27 time s greater than those based on mean values. Over 40% of sites requiring remediation would shift into the discretionary cleanup range if mean parameters were used. Though this paper examines the effect of using m ean parameters for contaminant concentrations, exposure duration, and ingestion rates, additional adjustments for other conservative paramet ers might increase this effect. (C) 1997 Academic Press.