Occurrence of Glucocorticoids, Mineralocorticoids, and Progestogens in Various Treated Wastewater, Rivers, and Streams.

In the current study a high sensitive analytical method was developed for the determination of 60 steroids including glucocorticoids (GC), mineralocorticoids (MC), and progestogens (PG) in WWTP effluents and surface water using liquid chromatography with tandem mass spectrometry detection (LC-MS/MS). The limits of quantification (LOQ) ranged between 0.02 ng/L (cortisone) to 0.5 ng/L (drospirenone) in surface water and from 0.05 ng/L (betamethasone) to 5 ng/L (chlormadinone) in treated wastewater. After optimization, the developed method was applied to WWTP effluents, rivers, and streams around Germany. Numerous steroids have been detected during the sampling campaign and predominant analytes from all steroid types were determined. Moreover, the occurrence of dienogest, mometasone furoate, flumethasone pivalate, and the metabolites 6ß-hydroxy dienogest, 6ß-hydroxy triamcinolone acetonide, 7α-thiomethyl spironolactone, and 11α-hydroxy canrenone is reported for the first time. In addition, this study revealed the ubiquitous presence of topically applied GC monoesters betamethasone propionate, betamethasone valerate, and 6α-methylprednisolone propionate in WWTP effluents and surface water.

Fate and behavior of progestogens in activated sludge treatment: Kinetics and transformation products.

Previous studies have shown the high ecotoxicological potential of progestogens (PGs) on the reproductive system of aquatic organisms. Yet the ubiquitous presence of several PGs in wastewater treatment plant (WWTP) effluents indicates an incomplete removal during treatment. To investigate the fate and behavior of PGs during biological wastewater treatment, nine commonly used PGs were incubated in aerobic lab-scale degradation experiments with activated sludge taken from a municipal WWTP. The degradation kinetics revealed a fast removal after 48 h for most of the compounds. Cyproterone acetate and dienogest were the most recalcitrant of the analyzed steroids with half-lives of 8.65 h and 4.55 h, respectively. Thus, only moderate removals of these PGs can be predicted in full-scale WWTPs. Moreover, numerous transformation products (TPs) were detected via high-resolution mass spectrometry. Hydrogenation or dehydrogenation of ring A and non-selective hydroxylations of 17α-hydroxyprogesterone derivatives (medroxyprogesterone acetate, chlormadinone acetate, cyproterone acetate) as well as for 19-nortestosterone derivatives (dienogest, norethisterone acetate, etonogestrel) were observed as major transformation reactions. Seven of the identified TPs were confirmed by reference standards. The biodegradation of cyproterone acetate revealed an almost quantitative transformation to 3α­hydroxy cyproterone acetate which is reported to be genotoxic. In a comparative evaluation of the TPs formed and the steroid structure, it was observed that molecular structure played a role in the inhibition of several transformation reactions, explaining the increased recalcitrance of these compounds. In addition, aromatization of the steroid ring A was identified for the 19-nortestosterone derivatives leading to the formation of estrogen-like TPs. For instance, the degradation of norethisterone acetate led to the formation of 17α-ethinylestradiol, a well-known and very potent synthetic estrogen. The evidence of the conversion of progestogenic to estrogenic compounds and the formation of potentially hazardous TPs indicates the need of a more comprehensive environmental risk assessment for synthetic steroids. Two of the newly identified TPs (3α-hydroxy cyproterone acetate and ∆9,11-dehydro-17α-cyanomethyl estradiol) were detected in WWTP effluents for the first time.

Analysis of the aerobic biodegradation of glucocorticoids: Elucidation of the kinetics and transformation reactions.

Glucocorticoids (GCs) are one of the most prescribed pharmaceutical classes worldwide. They have reached the focus as environmental pollutants in the current scientific research, due to their potential risks to aquatic organisms even in the lower ng L-1 range. The objective of this study was to determine the kinetic behavior of selected GCs and to identify their main transformation products (TPs) in lab scaled biodegradation experiments. Therefore, we analyzed the removal of 13 GCs in aerated incubation experiments with activated sludge taken from a German municipal wastewater treatment plant (WWTP) as inoculum. For all steroids, an exponential decrease of the concentrations was observed, which was modelled by pseudo-first order kinetics. Overall, the rate constants kbiol. ranged from 0.07 L gss-1 d-1 (triamcinolone acetonide) to 250 L gss-1 d-1 (prednisolone). These results emphasize the broad variation in the biodegradability and recalcitrance of certain GCs. The selection of the studied GCs enabled a deduction of microbiological stability related to functional groups. Based on the identified TPs, a variety of enzymatically mediated reactions were postulated. Moreover, the identified TPs are characterized by an intact steroid core structure. Thus residual endocrine activity cannot be ruled out. The main observed reactions were regioselective hydrogenation of carbon double-bonds, degradation of the steroid C17 side-chain, ester hydrolysis and oxidative hydroxylation. In total, 41 TPs were tentatively identified and 22 of them were unambiguously confirmed via reference standards. Additionally, 12 TPs were detected in the effluents of municipal WWTPs and, to the best of our knowledge, the occurrence of eight of these TPs has been shown for the first time. These TPs might significantly contribute to the detected residual endocrine activities in the aquatic environments. Therefore, there is a strong need for efficient removal strategies, in particular for persistent steroid hormones with elevated potencies.