Currently, estrogenic hormones are listed by the EPA as CCL 3 and do not have a safe drinking water level regulation set forth by The Safe Drinking Water Act (SDWA). In general, water/sewage treatment plants remove almost all the synthetic estrogen associated with oral contraceptives & hormone replacement, 17α-ethinylestradiol (EE2), whereas naturally occurring estrogens, such as 17β-estradiol (E2), may persist. Exposure to estrogenic compounds has a detrimental effect on ecological health including hermaphroditism, feminization, and death of aquatic organisms. Public awareness of estrogenic compounds in drinking water has bolstered misconceptions of oral contraceptive disposal as the culprits of imperiled ecosystems rather than natural estrogenic hormones and endocrine disrupting chemicals (EDCs), which are the suggested water contaminants of concern.
Maryland’s drinking water supply is primarily sourced from surface water that feeds into the Liberty, Loch Raven and Prettyboy reservoirs. Within each of the three watersheds, four representative test were identified and sampled seasonally (autumn, winter, spring & summer). Of those four, two test represented urban and agricultural areas, and the other two represented downstream of rural areas. Ecologiena’s Estrogen (E1/E2/E3) ELISA kit and Multiskan GO microplate reader were used to detect three naturally occurring estrogenic compounds: estrone (E1), 17β-estradiol (E2), and estriol (E3). Kit quantitative analyses ranged from a minimum of 0.05µg/L to a maximum of 3µg/L (ppb) for the estrogen (ES) compounds. Since E1 & E3 are present in reduced amounts, the final quantitative analysis represents 17β-estradiol, the most biologically active estrogen of the three compounds.
Results/Conclusions
Data analyses revealed no significant difference in the estrogen levels between the different test sites nor seasonally. Based on the measured optical density, we determined that there are traces of estrogen detected in Baltimore watersheds during the autumn season. The averages estrogen levels in The Loch Raven sub-sheds were 68 x 10^-6 ppm for LRW1, 79 x 10^-6 ppm for LRW2, 76 x 10^-6 ppm for LRW 3, and 78 x 10^-6 ppm for LRW4. In Liberty sub- sheds it was 49 x 10^-6 ppm LW 1, 43 x 10^-6 ppm in LW2, and 46 x 10^-6 ppm in LW3.In Prettyboy the averages of the sub-sheds were 69 x10^-6 ppm for PB1, 73 x10^-6 ppm for PB3, and 58 x10^-6 ppm for PB4.Of all the sites Loch Raven had higher levels of estrogen. Future work will determine if estrogenic compounds bioaccumulate in aquatic organisms gathered from the three aforementioned watersheds.