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SEASONAL RELEASE OF ESTROGENICALLY ACTIVE WASTEWATER: AN ASSESSMENT UTILIZING IN SITU BIOMARKERS
Citation:
Tilton, F., D. K. Schlenk, AND W H. Benson. SEASONAL RELEASE OF ESTROGENICALLY ACTIVE WASTEWATER: AN ASSESSMENT UTILIZING IN SITU BIOMARKERS. SETAC 20th Annual Meeting, Philadelphia, PA, 14-18 November 1999.
Description:
The estrogenic activity associated with effluent from two activated sludge municipal wastewater treatment plants (WWTP) was assesesed from 1996 through 1998. Fish were maintained at two sites within each WWTP; sites were located at pre-chlorination and the post-chlorination wastewater streams. Mature male channel catfish (n=10; 200 to 400 g) were placed in cages at each experimental and reference (REF) site and exposed in situ for 21 days. Levels of serum vitellogenin (VTG), for Fall 1996 were 1- to 2.5-fold above REF values. For Fall 1997 and Spring 1997, serum VTG levels were 4.8 fold and 3.4- to 3.8-fold greater than REF, respectively. Summer 1998 serum VTG was elevated 1- to 2-fold above REF. Hepatic CYP1A content was significantly increased 1.4-10.1 fold greater than REF during all seasons. Hepatic ethoxyresorufin O-deethylase (EROD) activity was elevated greater than REF, 1.0-4.1-fold at all sites. The seasonal trends in VTG induction were correlated to two common WWTP parameters utilized to monitor metabolic activity of microbial populations responsible for the aerobic degradation of municipal wastewater. Many natural (e.g. estradiol) and synthetic estrogens (ethinyl estradiol) are metabolized by activated sludge and therefore the variation of the metabolic efficacy of microbial populations within the WWTP may explain the seasonal release of the estrogenically active substance(s).