The potential for estradiol and ethinylestradiol degradation in english rivers

Abstract

Water samples were collected in spring, summer, and winter from English rivers in urban/industrial (River Aire and River Calder, Yorkshire, UK) and rural environments (River Thames, Oxfordshire, UK) to study the biodegradation potential of the key steroid estrogen 17beta-estradiol (E2) and its synthetic derivate ethinylestradiol (EE2). Microorganisms in the river water samples were capable of transforming E2 to estrone (E1) with half-lives of 0.2 to 9 d when incubated at 20 degrees C. The E1 was then further degraded at similar rates. The most rapid biodegradation rates were associated with the downstream summer samples of the River Aire and River Calder. E2 degradation rates were similar for spiking concentrations throughout the range of 20 ng/L to 500 microg/L. Microbial cleavage of the steroid ring system was demonstrated by release of radiolabeled CO2 from the aromatic ring of E2 (position 4). When E2 was degraded, the loss of estrogenicity, measured by the yeast estrogen screen (YES) assay, closely followed the loss of the parent molecule. Thus, apart from the transient formation of E1, the degradation of E2 does not form other significantly estrogenic intermediates. The E2 could also be degraded when incubated with anaerobic bed sediments. Compared to E2, EE2 was much more resistant to biodegradation, but both E2 and EE2 were susceptible to photodegradation, with half-lives in the order of 10 d under ideal conditions.

The fate and behavior of selected endocrine disrupting chemicals in full scale wastewater and sludge treatment unit processes

“…This apparent anomaly in the increase in E1concentration is explained by the biological conversion of E2 to E1 during the treatment process and in the sludge route. This abnormal behaviour has also been observed in previous studies (Nasu et al, 2001;Jurgens et al, 2002;Hashimoto et al, 2007;Ren et al, 2007). This also explains why E1 persist in both the effluent and sludge from the WWTPs.…”

Harnessing Natural Attenuation of Pharmaceuticals and Hormones in Rivers

“…Williams et al gave biodegradation and sorption as the predominant attenuation mechanisms for estradiol. This conclusion was based on the observation of a shorter half-life for estradiol in the river than what laboratory photolysis studies had suggested (22), paired with the unlikeliness of volatilization. Therefore, the remaining possible mechanisms are sorption and biodegradation.…”

The occurrence, causes, and consequences of estrogens in the aquatic environment

“…It would be difficult to think of a more environmentally relevant parameter than reproduction when attempting 2084 All Supplemental Data may be found in the online version of this article. See Table S1 for the number of citations and rank of all the ''Top 100'' papers, which in this essay are references [3][4][5][6][7][9][10][11][12][13][14][15]19,20].…”

“…There are undoubtedly very many unanswered questions relating to the issue of estrogens in the environment. For example, very little is known about the importance of degradation (by whatever means) in controlling the concentrations of estrogenic chemicals in the aquatic environment [19]; hence, predicting environmental concentrations of the chemicals of concern is still difficult. Similarly, many, and perhaps most, estrogenic chemical have a range of effects on aquatic organisms.…”