Developmental and Reproductive Abnormalities Associated with Endocrine Disruptors in Wildlife

Abstract

Since the middle part of this century, humans have become increasingly aware of their impact on the environment. Some examples of human impact on the environment include the developmental deformities and population declines of several species of birds around the Great Lakes, acid rain-associated loss of fish in northeast USA lakes, and human reproductive health problems attributed to industrial dumping at Love Canal, New York, USA. These and other examples have changed the way humans view their impact on the environment. Concern over the health and welfare of humans, as well as other organisms, has driven mankind to try to understand and manage this impact. One of the areas that scientists are focusing on is the alteration of normal endocrine system function by chemicals in the environment. In this chapter we present a brief review of the developmental and reproductive abnormalities associated with exposure to endocrine disrupting chemicals (EDCs). Although this chapter focuses on data from wildlife research, where necessary, we also provide examples from research conducted on domesticated animals from aquaculture, agriculture, and laboratory studies. We begin with a definition and a historical perspective of the field of toxicology. Following a definition of the endocrine disruption hypothesis, we present a synthesis of some of the data. This presentation is organized around four hierarchical levels of endocrine system function that include the control, production, availability, and action of hormones. Next, we discuss areas of cutting edge research, suggest areas for future study, and underscore the need to explore possible population-level effects of exposure to EDCs.