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Framework for Application of the Toxicity Equivalence Methodology for Polychlorinated Dioxins, Furans, and Biphenyls in Ecological Risk Assessment (Final)
Citation:
Framework for Application of the Toxicity Equivalence Methodology for Polychlorinated Dioxins, Furans, and Biphenyls in Ecological Risk Assessment (Final).
Impact/Purpose:
This framework helps to clarify this methodology’s strengths, limitations, and role within the broader context of ecological risk assessment.
Description:
Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) are persistent contaminants found widely in the environment. Several of these compounds bioaccumulate in the tissues of fish, birds, and mammals and have been shown to cause mortality and adverse effects on reproduction, development, and the immune system. EPA has developed a framework intended to assist Agency scientists in using a method known as the toxicity equivalence methodology to evaluate the ecological risks of these chemicals. The methodology offers a means to derive a single exposure estimate from multiple chemical concentrations found in environmental mixtures so that risk assessors can consider their cumulative impacts.