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2L - Immunotoxicity - genotoxicity - ED (WEP/116) The Recombinant Yeast Assay as a tool for the screening of estrogenic and androgenic activities in waste and surface water samples. Waldmann, Petra 1, Equit, Heike 1, Jumperts, Sophie1, Handel, Annette1, 1 AMMUG, University, Mainz, RLP, Germany ABSTRACT- Two strains of yeast transformed with plasmids encoding the human estrogen (androgen) receptor and an estrogen (androgen) responsive promotor linked to a reporter gene were evaluated for screening of receptor mediated estrogenic (androgenic) activities in waste and surface water samples. Therefore the method had to be adapted to the usage of native water samples. Water samples of the river Rhine spiked with estradiol, octylphenol or testosterone showed clear concentration response curves. The detection limit for estradiol was found in a picomolar range and for octylphenol and testosterone in a nanomolar range. In coded samples spiked with ethinylestradiol and dehydrotestosterone a recovery of 65 and 70 % was obtained. Samples of several industrial discharges displayed significant estrogenic activities, which decreased diluting the samples. 13 of 16 tested waste waters showed an estrogenic effect. Compared to the estrogenic potentials measured in river water, in some cases also tested in front and behind the discharge, sewage water activities were increased up to factor 6. Even in the water of the river Rhine enhanced estrogenic potentials (factor 1.5 to 2.5) were detected measuring almost continuously for 6 month. Androgenic activities were not found in river water, but only a few samples had been tested. The recombinant yeast assay represents a test system with an exquisite sensitivity and ease of use. Estrogenic, antiestrogenic, androgenic and probably antiandrogenic effects can be detected in one experiment. These attributes argue for the suitability of the recombinant yeast assay for the screening of native water and other environmental samples. However, the test system is limited to the detection of receptor mediated estrogenic (androgenic) activities and lacks biotransformation. The latter criteria are acceptable for screening, but risk assessment requires additional test systems. Key words: estrogen, endocrine disruptors, androgen, recombinant yeast system |
