DIFFERENT APPROACHES TO THE EVALUATION OF HUMAN HEALTH IMPACTS OFMERCURY VIA THE FISH INGESTION PATHWAY

摘要

In developing the current guidance for conducting human health risk assessments on combustionemissions in 1998, EPA adopted a conservative approach to the evaluation of mercury impacts via thefish ingestion pathway. Although some of this conservatism was tempered in the 1999 Errata document,many facilities have still had problems passing the risk assessment. Several factors contributing to thisconservatism will be described and alternative approaches proposed. These will include: consideration ofnon-default mercury speciation in stack emissions; the use of alternatives to the default bioaccumulationfactor (BAF) for methylmercury; and consideration of alternative fate and transport models. In addition,modified approaches for evaluating the mercury-fish ingestion pathway, considered by various stateregulatory agencies, will be described and compared to the national guidance.