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.

Treatment of Micropollutants in Water and Wastewater

“…In the same experimental set up, EE2 appeared to be stable. The findings for the conversion of E2 to E1 were confirmed in experiments with river water samples, in which E2 was converted into E1 and mineralised according to first order kinetics (Jürgens et al, 2002). The findings for the conversion of E2 to E1 were confirmed in experiments with river water samples, in which E2 was converted into E1 and mineralised according to first order kinetics (Jürgens et al, 2002).…”

“…Regarding the fate of steroid hormones in the environment, these compounds are highly hydrophobic, low volatile and present low polarities with octanolwater partition coefficients (K ow ) ranging between 10 3 and 10 5 . Jürgens et al (2002) studied the behaviour of E2 and EE2 in surface waters. investigated the distribution of several estrogens between water column and sediments and they reported that they can be rapidly removed from Servos et al, 2005 4-7 France Cargouet et al, 2004 17b-estradiol (E2) 1-15 Canada Servos et al, 2005 5-9 France Cargouet et al, 2004 17-ethinylestradiol (EE2) 3-5 France Cargouet et al, 2004 water phase to sediments.…”

“…Bed sediment was used to examine anaerobic degradation of E2; which was fairly rapidly converted to E1 at 20 -C, almost completely after an incubation of 2 days (Jürgens et al, 2002). Bed sediment was used to examine anaerobic degradation of E2; which was fairly rapidly converted to E1 at 20 -C, almost completely after an incubation of 2 days (Jürgens et al, 2002).…”

Presence of steroid hormones and antibiotics in surface water of agricultural, suburban and mixed-use areas

“…Fate studies of estrogens in the environment show that some of them can persist for significant time in surface water. Jurgens et al (2002) reported that estradiol and estrone in stream water have half-lives of 0.1 and 11 days, respectively. This indicates that the persistence of these estrogens in surface water is due to ongoing release and not due to cumulative effect over a long term.…”

A national risk assessment for intersex in fish arising from steroid estrogens

“…5) used for each of the selected estrogens are shown in Table 3 (derived from Jurgens et al [15]). The values of k 20 and (Eqn.…”