Endocrine modulators: Risk characterization and assessment

Over the last several years, information has been accumulating that suggest s that adverse effects are being induced in certain wildlife species. and p erhaps also in humans, as a consequence of exposure to man-made chemicals t hat have been released into the environment. Many of these effects have bee n attributed to interactions with various hormone systems in endocrine tiss ues. Most often the effects observed have been effects on reproduction and development, although there an also (often conflicting) data regarding an a ssociation between exposure and certain kinds of cancer, particularly cance rs of reproductive tissues such as breast and testis: effects on the immune system have also been noted. The substances To which these attributes have been ascribed have come to be known as "endocrine modulators" or "endocrin e disrupters." The full nature and scope of the "prohlem" of endocrine modu lators/disruptors is currently a matter of great debate, both within and ou tside of the scientific community. Regulatory authorities around the world are being asked what their position is on this issue and what, if any, regu latory strategies they are developing to address the: problem. In many case s, because of the nature of the legislation under which governments manage chemicals, regulatory decisions must be informed by risk assessment. This p resentation will describe the general approach to the risk assessment of en docrine modulators/disruptors as practiced by the US government, with parti cular focus on the current practices/policies of the US Environmental Prote ction Agency.