Appropriate Uses of Physiological Techniques for Endocrine Studies

The recent explosion of interest in the potential of chemicals to disrupt endocrine processes at very low exposure levels has led to the increased use of physiological tools in field studies. Physiological studies have not been fully developed for ecotoxicological applications and are underappreciated or poorly utilized. In ecotoxicological studies, physiological tools have historically been focused on direct impacts of specific chemicals, and usually on general indicators of health or exposure. The result has been that most surveillance programs have only used physiological tools for the assessment of exposure. An increasing need to link responses in wild fish with the underlying ecological mechanisms means that physiological studies have to play a key role in the assessment of impact. However, the use of physiological studies in endocrine assessments requires a level of detail not previously warranted in ecotoxicological studies. This overview will discuss the limitations of physiological indicators, as well as critical areas requiring further study and the requirements for the future development of physiological indicators of endocrine disruption.