The study of endocrine-disrupting compounds: past approaches and new directions

Over the last decade, evidence has mounted demonstrating that human-made compounds released into the environment are disrupting endocrine systems of animals. Research has centered largely on direct steroidogenic or antisteroidogenic effects of these compounds with a recent focus on development of rapid in vitro assays employing estrogen receptors. A literature search and analysis confirms attention placed on estrogen and anti-estrogen-like aspects of endocrine disruption at the receptor level. Non-steroidal components of the hypothalamic-pituitary-end gland axes have received much less attention in the published endocrine disruption literature. Furthermore, aspects of endocrine physiology, such as the ability of animals to cope with stress or communicate chemically, have also received relatively less literature attention when compared to disruption of development and reproduction. As researchers continue to investigate complex mixes of human-synthesized compounds in the environment, it is critical to broaden the spectrum of hormonal disruption investigated beyond estrogenic and androgenic actions and to determine how exposure to mixes affects physiological function beyond reproduction. Last, in the field of endocrine disruption, it also important to begin to use data on individuals for development of hypotheses regarding fitness risks, changes in population dynamics, and the potential for ecosystem level disruption.