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17alpha-ethinylestradiol (EE2), the active compound of the contraceptive pill, is a recalcitrant estrogen, which is encountered at ng/l levels in wastewater treatment plant (WWTP) effluents and rivers and can cause feminization of aquatic organisms. The aim of this study was to isolate micro-organisms that could remove such low EE2 concentrations. In this study, six bacterial strains were isolated from compost that co-metabolize EE2 when metabolizing estrone (E1), 17beta-estradiol (E2) and estriol (E3). The strains belong to the alpha, beta and gamma-Proteobacteria. All six strains metabolize E2 over E1, at microg/l to ng/l concentrations. In 4 days, initial concentrations of 0.5 microg E2/l and 0.6 microg EE2/l were degraded to 1.8 +/- 0.4 ng E2/l and 85 +/- 16 ng EE2/l, respectively. No other metabolites besides E1, E2, E3 or EE2 were detected, suggesting that total degradation and cleavage of the aromatic ring occurred. This is the first study describing that bacteria able to metabolize E2, can subsequently co-metabolize EE2 at low microg/l levels.

Knowledge of the presence of micropollutants such as pharmaceuticals, in coastal areas, is very limited; therefore, the main objective of this study was to optimize and validate a new analytical method for the quantitative analysis of 13 multiclass pharmaceuticals in seawater. Target compounds included antibiotics, non-steroidal anti-inflammatory drugs, beta-blockers, lipid regulators and one psychiatric drug. A combination of solid-phase extraction and liquid chromatography coupled with multiple mass spectrometry enabled their detection at the low nanogram per litre level. The limits of quantification varied between 1 and 50 ng L(-1), for most components the linearities were more than 0.99 and the recoveries obtained in seawater (95-108%) were satisfactory. This method was applied to seawater and estuarine water samples collected in the Belgian coastal zone, to assess the prevalence of common pharmaceuticals in this marine environment. Seven pharmaceuticals, including compounds of which the presence in marine environments had not been reported earlier, were detected, with salicylic acid and carbamazepine being the most abundant, in concentrations up to 855 ng L(-1).