Assessing the Bioactivity of Estrogens, Including Halogenated Derivatives, in Chlorinated Sewage Effluents and Coastal Seawater

This project seeks to measure halogenated estrogens in the waters of Massachusetts Bay, thus enabling a realistic assessment of the risk posed by these compounds to fisheries and coastal ecosystem health. Currently these steroidal hormones are making their way into both fresh and ocean waters, where they cause anomalies such as the feminization of fish, which has been seen in response to exposures to sewage effluent. Results will provide the first integrated assessment of the bioactivity of halogenated derivatives relative to other estrogen forms and provide new data to the Massachusetts Water Resources Authority relevant to their on-going efforts to protect the health of the Massachusetts Bay ecosystem.

Objectives:
(1) To determine the freely dissolved concentrations of parent and halogenated estrogens within procedures used to measure their estrogenicity, since we hypothesize that these tests include many phases (e.g., plasticware; organismal lipids) that take up estrogens from solution and lower their chemical activity.
(2) To determine the estrogenicity of halogenated estrogen derivatives using a combination of in vitro, cellular, and in vivo assays in which we simultaneously measure freely dissolved concentrations in the system.
(3) To quantify the contribution of halogenated derivatives to the total estrogenicity of MWRA sewage effluent and seawater samples from stations near the sewage discharge in Massachusetts Bay.

Methodology: We will use non-depletive solid phase microextraction (nd-SPME) with subsequent HPLC-MS/MS or 3H-scintillation counting analyses to assess the truly dissolved concentrations of estrogens and halogenated derivatives under conditions used to quantify their estrogenicities during in vivo and in vitro bioassays using killifish and zebrafish systems. By evaluating these data as a function of those compounds' properties (pKa and Kow), we will establish dose correction factors needed to evaluate the estrogenicity of halogenated estrogens and demonstrate any need for improved approaches (e.g., substitute glass for plastic vessels). With new estrogenicity data for halogenated estrogens, we will compare measures of total estrogenicity found in samples of MWRA sewage effluents and Massachusetts Bay seawater near the sewage outfall.

Rationale: These results should lead to improved monitoring procedures aimed at assessing effluent estrogenicities and their chemical cause(s). Moreover, we will provide the first integrated assessment of the bioactivity of halogenated derivatives relative to other estrogen forms. Finally, we will provide new data to the MWRA relevant to their on-going efforts to protect the health of the Massachusetts Bay ecosystem. Successful completion will also inform national and international efforts to characterize diverse chemicals for their possible roles as endocrine disruptors.