Wild organisms are exposed to a variety of chemical and nonchemical stressors, complicating the identification of a definitive cause. In many cases, the chemicals associated with effects already have been identified as problem substances due to their toxicity and persistence and therefore are heavily regulated or banned from commercial use in the United States. Examples include DDT, PCBs, and certain heavy metals. It is difficult to discern whether endocrine effects on individuals of a particular species have impacted populations of that organism or the community of which it is a part. The most credible examples illustrating significant population declines as a result of exposure to endocrine-disrupting chemicals have been reported for alligators in central Florida and some local populations of marine invertebrate species.
Further research is needed to better understand population-level effects.
Implications of the Report for EPA Based on the report, EPA is concerned about the possibility of impacts to human health and the environment due to exposure to endocrine disruptors. Given the current state of the science, the Agency does not consider endocrine disruption to be an adverse endpoint per se, but as a step that could lead to toxic outcomes, such as cancer or adverse reproductive effects. This perspective could change as additional data become available. EPA can use evidence of endocrine disruption in setting priorities for further testing to see if other effects are likely and if regulatory actions are necessary. EPA will continue current efforts to reduce risks from environmental chemicals and to investigate their potential to cause endocrine disruption in cooperation with other federal agencies and organizations, both domestic and international.