Occurrence and Photochemical Degradation of Estrogenic Steroids in Coastal Seawater

University Of Massachusetts, Dartmouth, North Dartmouth MA

Investigators

Abstract

Estrogenic hormones and related synthetic steroids, such as those used in contraceptive pills and hormone replacement therapy drugs, have been shown to be present in the aquatic environment, mainly as a result of inefficient removal in wastewater-treatment plants (WTPs). The concentrations of the compounds, although very low (sub-ng to a few ng/L), are sufficient to induce estrogenic responses and alter the normal reproduction and development of wildlife organisms. Of estrogenic compounds, synthetic contraceptive steroid, such as 17á-ethinylestradiol (EE2), are found to be the most potent endocrine disruptor. It can cause feminization of male fish even at extremely low concentrations (e.g. 0.1 ng/L). The Buzzards Bay in Massachusetts, like many other coastal environments near densely populated cities, receives stormwater runoff and effluents from wastewater treatment facility (for example, New Bedford and Fairhaven WTPs discharge their effluents directly into Buzzards Bay). This leads to direct input of many different classes of pollutants, including endocrine-disrupting estrogens into Buzzards Bay. In this study, researchers at the University of Massachusetts at Dartmouth will use Buzzards Bay as a representative of coastal environments close to densely populated cities to study the sources, transportation, concentration variation, microbial and photochemical transformation of estrogenic hormones in coastal seawater. The principal investigator?s preliminary study has shown that the concentration of EE2 and other estrogenic steroids were over 5 ng/L in Acushnet river estuary seawater, at which they may significantly affect fish and other wildlife in the Bay. The main objectives of this proposed research are to: (1) examine the sources and seasonal concentration variation of estrogenic hormones: estrone, 17â-estradiol, estriol, EE2 and mestranol in Buzzards Bay seawater; (2) assess the microbial and photochemical degradation rate of estrogenic hormones in Buzzards Bay; (3) determine the influences of natural dissolved organic matter, transition metal Fe, dissolved oxygen and irradiation wavelength on the photochemical degradation; (4) identify the intermediate products of photodegradation of estrogenic steroids and evaluate their estrogenic activity. In terms of broader impacts, this study will raise public awareness of the presence of estrogenic compounds in the nearshore environment and their impact to marine coastal ecosystems. The proposed project will be integrated into a teaching program by bringing the experimental techniques of marine aquatic photochemistry into the classroom. Through demonstrations, laboratory exercises, field studies and independent research projects, students will be able to apply what they have learned in their marine and chemistry courses, in an effort to understand that the well-known laws of physical chemistry not only apply in the laboratory but also regulate the course of reactions taking place in nature. Both graduate, undergraduate and high school students will participate in this research. Efforts will also be made to involve minority students in the proposed research and prepare them for a future career in a science related field. This project will also enhance infrastructure for research and education at the University of Massachusetts, Dartmouth.