title: 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.
authors.affiliation: Swiss Federal Institute for Environmental Science and Technology, Uberlandstrasse 133, Postfach 611, CH-8600 Dübendorf, Switzerland. etienne.vermeirssen@eawag.ch
authors.forename: Etiënne L M
authors.initials: EL
authors.lastname: Vermeirssen
authors.forename: Richard
authors.initials: R
authors.lastname: Burki
authors.forename: Caroline
authors.initials: C
authors.lastname: Joris
authors.forename: Armin
authors.initials: A
authors.lastname: Peter
authors.forename: Helmut
authors.initials: H
authors.lastname: Segner
authors.forename: Marc J F
authors.initials: MJ
authors.lastname: Suter
authors.forename: Patricia
authors.initials: P
authors.lastname: Burkhardt-Holm
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D004784:Environmental Monitoring / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay; D004958:Estradiol / Q000032:analysis / Q000737:chemistry; D004967:Estrogens / Q000032:analysis*; D005656:Fungal Proteins / Q000737:chemistry; D008297:Male; D048789:Phytoestrogens / Q000032:analysis*; D045483:Rivers; D012621:Seasons; D013557:Switzerland; D014337:Trout; D014819:Vitellogenins / Q000097:blood* / Q000737:chemistry; D014867:Water / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*; D015003:Yeasts / Q000378:metabolism
chemical_list: D004967:Estrogens; D005656:Fungal Proteins; D048789:Phytoestrogens; D014819:Vitellogenins; D014874:Water Pollutants, Chemical; D014867:Water; D004958:Estradiol