Toxicological Significance of Pesticide Residues in Aquatic Animals

This chapter describes the significance of pesticide bioaccumulation; the relationship between body residues and toxicity; biotransformation processes in aquatic animals; the impact of biotransformation on toxicological endpoints; and the environmental and physiological factors that can influence bioaccumulation and toxicity. It focuses on the impacts of insecticide toxicity on aquatic animals, even though the general concepts covered are applicable to all pesticides. Enzymes generally involved in phase I biotransformation of pesticides by aquatic animals are cytochrome P450 monoxygenases, flavin-containing monooxygenases, esterases, and other hydrolases, while glutathione-S-transferase, glucuronosyltransferases, sulfotransferase, and acetyl transferase may involve in phase II reactions. The differential abilities to biotransform pesticides were demonstrated among aquatic animals as well. In summary, aquatic animals are capable of biotransforming pesticides, and typically in the order of fish, arthropods, mussels, and annelids. The chapter summarizes the toxicological significance of pesticide accumulation to aquatic animals.