Occurrence and Effects of Endocrine Disrupting Chemicals in the Environment

This review focuses on environmental chemicals that mimic the activity of the endogenous estrogen, 17b-estradiol ~E2!, and their effects on wildlife, because it is the most studied area of endocrine disruption. The potential human health impact of endocrine disruptors is beyond the scope of this paper and readers should refer to other publications as reported by Crisp et al. in 1998 and Safe in 1995. The concentrations of endocrine disrupting chemicals in effluents from sewage treatment plants ~STPs! are summarized and compared. By utilizing in vitro and in vivo assays, environmental estrogens from STPs and other point source pollutants have been shown to induce reproductive abnormalities in fish and wildlife. Though treatment systems of sewage facilities can reduce the amounts of endocrine disrupting chemicals, the removal efficiency can still be improved to further reduce estrogenic effects upon aquatic organisms. Up to date, a lack of comprehensive research impedes the ability to correlate estrogenic chemicals to community- and ecosystem-level effects. Thus, total ecosystem evaluations such as species diversity and impact on keystone species and understudied nonpoint source pollution should be two primary focuses of future research.