Toxicological Implications of PCBs, PCDDs, and PCDFs in Mammals

Abstract

This chapter provides a review of literature pertaining to the exposure of mammalian wildlife species to polychlorinated biphenyls (PCB), Polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) and aims to interpret those data in terms of potential for adverse effects as they relate to tissue concentrations. An overview of the chemistry, uses, and sources of PCBs/PCDDs/PCDFs is followed by a description of the spatial and temporal trends of these chemicals in mammalian wildlife species. Because the majority of toxic effects associated with exposure to PCBs/PCDDs/PCDFs are presumed to result from interaction with the aryl hydrocarbon receptor, an overview of the mechanism of action of chemicals is provided. Field studies usually involve the assessment of tissue concentrations of PCBs, PCDDs, and PCDFs, or in some cases, toxic equivalents with subsequent comparison of concentrations to tissue concentrations associated with deleterious effects as determined in laboratory feeding studies.