Steroid analysis and xenosteroid potentials in two small streams in southwest Germany

The presence of estrogenic substances in thewater of the small streams Körsch (Kö)and Krähenbach (Kr), Southwest Germany, wasdetermined by chemical and biological analysis.Because a large proportion of the Kö waternear its mouth consists of sewage treatmentplant (STPs) effluents, the impact of STPs onlevels of estrogens in surface water is anenvironmental issue of concern. In July 1996,water samples were taken from Kr and Kö(four sites) and tested in the E-Screen assaywith human MCF-7 breast cancer cells. AllKö samples induced estrogen-dependent cellproliferation resulting in 17-estradiolequivalent concentrations (EEQ) between 3.3 and9.7 ng/L while the Kr water showed no effect.In 1998/99 eight samples from Kö (near itsmouth) and nine samples from Kr were collectedand tested in the E-Screen after solid phaseextraction. Some estrogenicity was detectablein three Kr samples but Kö samples had amedian EEQ of 3.1 ng/L (range: 1.2–42 ng/L).GC/MS analysis revealed differences in thelevels of 17-estradiol and estronebetween the two streams. 17-estradiolwas detectable in five Kö samples only (0.7–1.8 ng/L). Estrone was found in the Köfrom 2.5 to 38 ng/L (median: 7.6 ng/L) and inthe Kr between 0.8 and 22 ng/L (median: 1.7 ng/L). Analysis for nine phenolic xenoestrogensrevealed rather low levels for five compoundswhich occurred more frequently and in higherconcentrations in the Kö. After asemi-field exposure of adult male rainbow troutfor 4 weeks in Kö water, plasmavitellogenin levels were significantly highercompared to those levels detected in the sameanimals before exposure.