Effects of advanced treatments of wastewater effluents on estrogenic and reproductive health impacts in fish.

Whether the implementation of additional treatments for the removal of estrogens from wastewater treatment works (WwTWs) effluents will eliminate their feminizing effects in exposed wildlife has yet to be established, and this information is crucial for future decisions on investment into WwTWs. Here, granular activated carbon (GAC), ozone (O3), and chlorine dioxide (ClO2) were investigated for their effectiveness in reducing steroidal estrogen levels in a WwTW effluent and assessments made on the associated estrogenic and reproductive responses in fathead minnows (Pimephales promelas) exposed for 21 days. All treatments reduced the estrogenicity of the standard-treated (STD) effluent, but with different efficacies; ranging between 70−100% for total estrogenicity and 53−100% for individual steroid estrogens. In fish exposed to the GAC- and ClO2- (but not O3-) treated effluents, there was no induction of plasma vitellogenin (VTG) or reduction in the weight of the fatpad, a secondary sex character in males,...