PREDICTING HUMAN HEALTH AND ECOLOGICAL RISKS FROM PCB-CONTAMINATED SEDIMENTS: LESSONS LEARNED

摘要

This paper will present an overview of important issues to consider when predicting human health and ecological risks from exposure to PCBs in sediments. We will discuss each aspect of the risk assessment process, including hazard identification and problem formulation, exposure assessment, effects assessment, and risk characterization. We will emphasize the following issues in our discussion: (1) the use of Aroclor versus congener data, including the advantages and limitations of each type of data; (2) the use of different bioaccumulation models to estimate exposure and the data requirements of these models; (3) an evaluation of uncertainty and variability in a typical sediment-based food web; and (4) tiered approaches to assessing risks that allow risk managers to refine risk estimates depending on data availability. The issues will be considered within the context of a case study involving a decision to place dredged sediments containing PCBs at an offshore, open water disposal site.