Xenoestrogen exposure and effects in bluegill from the Reedy River, South Carolina, USA.

Water quality in the Reedy River basin of Greenville, South Carolina, has been impacted by diverse and highly urbanized land uses. It has been demonstrated that urban runoff and point sources, such as effluent from wastewater treatment facilities, introduce organic pollutants and potentially endocrine disrupting compounds (EDCs) into the watershed. The objective of this study was to investigate the potential toxicological effects of EDCs that may be present in the Reedy River watershed using a set of biomarkers measured in indigenous fish to characterize the exposure and biological effects of these contaminants. Bluegill (Lepomis macrochirus) were collected during three different sampling seasons (spring, summer, and fall) from several sites along the length of the Reedy River and from an unimpacted site at Lake Robinson. Fish were analyzed for xenoestrogenic exposure (estrogenic effect of bile extracts) and effects (vitellogenin production in juvenile fish), which were compared to the hepatosomatic index as a general health parameter. Samples downstream of Greenville, especially downstream of the wastewater treatment facilities, were found to have significantly higher levels of estrogenic activity in bile extracts, which correlated well with elevated plasma vitellogenin concentrations relative to the specimens collected in reference sites. The results provide evidence that bluegill in the Reedy River were exposed to elevated concentrations of xenoestrogenic compounds and that these xenoestrogens were bioavailable, resulting in biological effects.