Characterization of the estrogenicity of Swiss midland rivers using a recombinant yeast bioassay and plasma vitellogenin concentrations in feral male brown trout

Abstract

In our study, we aim to characterize the estrogenicity of 18 independent rivers that receive effluent from sewage treatment works. During the winter and summer of 2003, we collected multiple water samples and measured environmental estrogens with an in vitro yeast-based reporter gene assay; estrogenicity was expressed as ng 17beta-estradiol equivalents (EEQ) per L of water. Estradiol equivalents values in winter ranged from 0.3 to 2.0 ng/L and, in summer, from 0.4 to 7.0 ng/L. Winter and summer EEQ values were not correlated with each other or with the dilution factor of the effluent in the river. Variation in EEQ values was large and correlated from winter to summer. Part of this variation in estrogenicity is explained by water flow rates; variation is larger at reduced flow rates. We measured plasma vitellogenin concentrations in immature male brown trout. At five sites, vitellogenin concentrations exceeded 1 microg/ml; however, at the majority of the sites, plasma vitellogenin concentrations were below 0.5 microg/ml. Our data indicate that the exposure of brown trout to environmental estrogens in Swiss midland rivers is low. However, some sites show reoccurring higher EEQ values and, at some sites, plasma vitellogenin concentrations in male fish clearly are elevated.

Determination of Estrogen Activity in River Waters and Wastewater in Luxembourg by Chemical Analysis and the Yeast Estrogen Screen Assay

“…Both sampling points 6 and 4 do receive the effluent of the WWTP of Reckange (point 1), which could explain the slightly higher values measured for sampling points 4 and 6, compared to the other surface water samples at point 5, a distinct location in another catchment. These levels of estrogenic activity in surface waters in Luxembourg are somewhat higher than those obtained by Vethaak et al (2005) in the Netherlands (LOD -0.61 pmol EEQ l -1 ) or Vermeirssen et al (2005) in Swiss midland rivers (0.3-7 ng l -1 E2 equiv.). Studies in Belgium (Witters et al, 2001; and in UK (Jobling et al, 2009) indicate estrogenic activity in surface waters, which is of similar magnitude as presented in this study.…”

“…Studies in Belgium (Witters et al, 2001; and in UK (Jobling et al, 2009) indicate estrogenic activity in surface waters, which is of similar magnitude as presented in this study. The measured estrogenic activity could contribute to reproductive disturbances of natural populations of fish as suggested by Vermeirssen et al (2005) who demonstrated increased vitellogenin levels in feral male brown trout. Jobling et al (2005) pointed to medium to high risk for occurrence of intersex in wild roach when estrogenic activity was 1-10 or > 10 ng l -1 E2 equivalents, respectively.…”

Estrogens in Swiss Rivers and Effluents – Sampling Matters

“…Rivers [17] Multiple independent yet similar locations were repeatedly sampled up and downstream from effluent discharges (Fig. 1).…”

“…It was concluded that possibly environmental conditions, but also method issues, contributed to the variability; particularly as the evaluation of the YES is not straightforward. [17,19] With the aim to produce a more robust data set, a second sampling campaign was conducted and 17 locations were sampled again in summer. This time, the three samples were collected with an exact two-week interval (± 3 h).…”

Retinoid X receptor activities of source waters in China and their removal efficiencies during drinking water treatment processes

“…The development of rapid response methods using simple equipment has also become an attractive alternative to conventional chemical analytical techniques [16]. Among bioassays that have been considered, the yeast assay was successfully applied to determine activities in chemical and/or environmental samples [17]. Although many EDCs can survive drinking water treatment, little is known about the fate of RXR activity in drinking water [18].…”