ABSTRACT
This chapter summarizes knowledge on tissue residues and ecotoxicological effects typically observed in aquatic organisms exposed to dioxins, polychlorinated biphenyls (PCBs), and Polybrominated diphenyl ethers (PBDEs). It also summarizes the physical and chemical properties of compounds that are important to understanding environmental fate, bioaccumulation, distribution in the environment, and the significance of tissue residues in aquatic organisms. The chapter discusses what is understood about the environmental fate of these compounds, with an emphasis on factors that influence exposure and toxicity. It includes an overview of toxic equivalency factors (TEFs) assigned to different dioxins and certain dioxin-like PCBs used to evaluate the significance of environmental exposures, and a discussion of recent TEF schemes proposed to aid PBDE risk assessment. Although scientific interest regarding the ecological effects of dioxins, PCBs, and PBDEs stems from our knowledge of human health, much work remains regarding assessing risks to aquatic organisms.
