Endocrine-Modulating Substances in the Environment: Estrogenic Effects of Pharmaceutical Products

Abstract

Several classes of anthropogenic substances modulate endocrine pathways. To date, most of the research has focused on chemical classes such as chlorinated hydrocarbon contaminants, pesticides, or degradation products of high-use industrial surfactants. However, little is known about the environmental impact of another important class of chem icals: hormonally active pharmaceutical products. This deficit of information is surprising, given the biological potencies of these widely used substances and their potential to enter the environment through sewage treatment effluents and runoff from agricultural applications. Estrogenic pharmaceutical products are used extensively in human estrogen-replacement therapy and oral contraceptive formulations. Estrogenic substances are also used as growth enhancement products in veterinary medicine. This report describes the potencies, pharm acokinetics, and metabolic pathways of such estrogenic products. The amounts of pharmaceutical-derived estrogens that reach the environment from doses and usage are estimated. Factors that affect environmental concentrations including metabolism and biodegradation are also considered. Finally, we present both chemical and analytical data, as well as bioassay evidence, that suggest that biologically active concentrations of estrogenic compounds are being released into the aquatic environment.