ABSTRACT
This chapter focuses mainly on the cyclodiene group of organochlorine (OC) pesticides, which includes aldrin, dieldrin, and endrin (the “drins”), as well as heptachlor and chlordane. It briefly considers several other OC pesticides such as endosulfan, hexachlorocyclohexane, and methoxychlor, which continue to be widely used, and hexachlorobenzene, mirex, and toxaphene, for which detectable residues continue to be reported regularly in wild birds. The chapter extends the assessments of sublethal effects, particularly for anorexic effects of dieldrin and consequences for breeding birds and migrants. It examines the literature on chronic effects of other OC pesticides in birds, and suggests criteria. The chapter suggests a simple model of “Dieldrin Toxic Equivalents” for assessing lethal concentrations of a mix of cyclodienes and also of Dichlorodiphenyl trichloroethanes in brain of birds. Additionally, J. L. Ludke's findings provide some empirical confirmation that cyclodienes, chlordane and endrin, act in an additive manner.
