Changing Concepts and Improved Methods for Evaluating the Importance of PCBs (Polychlorinated Biphenyls) as Dredged Sediment Contaminants

摘要

Polychlorinated biphenyls (PCBs) are highly persistent and widespread contaminants frequently encountered by Corps of Engineers personnel involved with dredged material disposal activities. Interpretation of the potential ecological effects of disposing PCB-contaminated sediments in open water or using other methods is a persistent difficulty in the preparation of environmental impact statements and other documentation necessary for informed decisionmaking. However, the understanding of the nature and behavior of PCBs as environmental contaminants has progressed rapidly within the scientific community with the advances in analytical technology of the past few years. This paper summarizes the current understanding of the chemical nature of PCBs, the factors determining their persistence and potential to bioaccumulate, and the characteristics of individual PCB congeners that determine their widely differing potencies and modes of toxic effect.