Populations of amphibians are in decline in certain locations around the world, and the possible contribution of environmental contaminants, including estrogenic compounds, to these declines is of potential concern. In the current study, responses of the wood frog (Lithobates sylvaticus) to exposure to 17α-ethynylestradiol (EE2), the synthetic estrogen used in oral contraceptives, during the la...

The mechanism, isotherms and kinetics of removal of two endocrine disrupting chemicals, 17β-estradiol (E2) and 17αethinyloestradiol (EE2) by activated carbon adsorption were investigated in an agitated non-flow batch adsorption studies. Mathematical models were used to describe the adsorption phenomenon with the kinetic and thermodynamic parameters evaluated using the adsorption equilibrium dat...

Several environmental xenobiotics have been found to affect the metamorphosis of amphibians. In this study we exposed tadpoles of the Common frog Rana temporaria from hatching to metamorphosis to two known endocrine disruptors, the estrogenic pharmaceutical 17 -ethinylestradiol and the antiandrogenic/antiestrogenic fungicide prochloraz to determine their effect on 1) days to metamorphosis and s...

Estrogens are important environmental contaminants that disrupt endocrine systems and feminize male fish. We investigated the potential for anaerobic biodegradation of the estrogens 17-alpha-ethynylestradiol (EE2) and 17-beta-estradiol (E2) in order to understand their fate in aquatic and terrestrial environments. Cultures were established using lake water and sediment under methanogenic, sulfa...

The release of human pharmaceuticals in the aquatic environment has become an issue of societal concern. More than 160 Active Pharmaceutical Ingredients (APIs) have been detected in surface waters, although generally at low concentrations (ng-ug/l). Most available ecotoxicological information on these pharmaceuticals originates from acute testing using algae, Daphnia and fish; results from long...

Endocrine-disrupting chemicals (EDCs) in municipal effluents directly affect the sexual development and reproductive success of fishes, but indirect effects on invertebrate prey or fish predators through reduced predation or prey availability, respectively, are unknown. At the Experimental Lakes Area in northwestern Ontario, Canada, a long-term, whole-lake experiment was conducted using a befor...

Studies in mammals have shown that exposure to estrogenic compounds can affect lipid metabolism and plasma concentrations of lipid-soluble vitamins. However, the potential for estrogenic contaminants to induce these effects in fish has not yet been examined. The ability of the estrogen analog ethynylestradiol (EE2) to alter concentrations of the lipid-soluble vitamins A and E in plasma, liver, ...

Sixteen steroids with different endocrine activities were administered to female rats for 6 or 7 days, in a broad range of doses. Liver growth was recorded by measuring weight and DNA contents and monooxygenase activity by assaying the turnover of five different substrates. According to their effects on these parameters steroids were assigned into one of the following three groups: (a) Estrogen...

Newly available prescription data has been used along with census data to develop a localised method for predicting pharmaceutical concentrations in sewage influent and effluent for England, and applied to a case study: the steroid estrogens estrone, 17β-estradiol, and 17α-ethinylestradiol in a selected catchment. The prescription data allows calculation of the mass consumed of synthetic estrog...