WP1 Wastewater Treatment Effluents: Endocrine Disrupters and Pharmaceuticals
Wednesday, 16 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall
(RIO-1117-840187) Rainbow trout as an indicator species of endocrine disruption in California surface waters.
Riordan, D.1, Biales, A.2, de Vlaming, V.1, Markiewicz, D.1, Holmes, R.3, Otis, P.4, 1 University of California, Davis, Aquatic Toxicology Laboratory, Davis, CA2 US EPA, National Exposure Research Laboratory, Molecular Indicator Research Branch, Cincinnati, OH3 Regional Water Quality Control Board, Region 5, Sacramento, CA4 Regional Water Quality Control Board, Region 1, Santa Rosa, CA
ABSTRACT- There is substantial evidence documenting the existence of endocrine disrupting chemicals (EDCs) in surface waters. Our goal is to develop and apply a short-exposure and economical method capable of detecting low concentrations of estrogenic EDCs in these waters. Our procedure involves exposing larval rainbow trout (Oncorhynchus mykiss) to water samples and analyzing their livers for vitellogenin mRNA (Vg) using SYBR Green or TaqMan® RT-qPCR (reverse-transcription quantitative polymerase chain reaction). Procedure development experiments with the synthetic estrogen 17
-ethinyl estradiol (EE2) indicated that concentrations as low as 10 ng/L of EE2 would up-regulate the Vg gene. Within treatment variability, however, was high. In an effort to reduce this variability, a series of experiments conducted in which test temperature, test chamber size, number of replicates per treatment and number of fish per replicate were altered. The most significant effect arose from increasing the number of fish per replicate. Liver samples from each of the three fish in a test chamber were pooled and analyzed by PCR as one sample. The result was the acquisition of data that were more normally distributed, and in some cases, allowed for parametric, rather than non-parametric statistical analyses. Currently, we are conducting a series of experiments with ambient surface water samples from various regions of California. Early findings indicate the presence of estrogenic EDCs. Follow-up studies with ambient samples, in conjunction with additional procedure development, are scheduled for summer, 2005.
Key words: endocrine disruption, vitellogenin, rainbow trout, rt-qpcr