A RISK-BASED SCREENING APPROACH FOR PRIORITIZING CONTAMINANTS AND EXPOSURE PATHWAYS AT SUPERFUND SITES

Contamination at Superfund sites can involve mixtures of chemicals and radionuclides in a variety of environmental media. Determining priori ties for evaluation and remediation of various contaminants is an impo rtant part of the initial phases of any site investigation. An effecti ve screening analysis at the beginning of the project can help by iden tifying both those situations in need of immediate remedial attention and those which require further sampling and evaluation, The screening approach discussed here is made up of two sets of calculations design ed to provide upper- and lower-bound estimates of health risk to indiv iduals likely to receive the highest exposures. This approach allows r apid identification of contaminants which pose a negligible risk and c an be assigned a low priority for remedial attention or which pose a s ubstantial risk and should be given the highest priority for appropria te remediation efforts. Contaminants designated as neither high- nor l ow-priority should be investigated in more detail prior to making deci sions regarding the need for or method of remediation. The utility of this approach has already been demonstrated in the evaluation of conta mination in the Clinch and Tennessee River systems originating from hi storical operations of atomic weapons and energy research facilities n ear Oak Ridge, Tennessee.