Comparison of in Vitro and in Vivo Bioassays for Estrogenicity in Effluent from North American Municipal Wastewater Facilities

Attempts to better understand causal factors affecting estroge-nicity in municipal wastewater have primarily focused on analyt-ical evaluation of specific chemical estrogens and the use of estro-gen receptor (ER) based in vitro assays. To compare analytical, in vitro, and in vivo assays for estrogenicity, wastewater from four New York and one Texas municipal wastewater facilities was evaluated for estrogenic activity using the yeast estrogen screen assay (YES) and an in vivo fish vitellogenin (VTG) assay. Estro-genic activity, as measured by the YES assay, was observed in methanol and/or methylene chloride eluents from C18 extracts in two of the New York treatment facilities and the Texas facility. Estradiol equivalents for the YES assay data ranged from<1 to 15 ng/l. Male Japanese medaka (Oryzias latipes) were then exposed for 7 days to solvent extracts from the New York-Red Hook facility and the Texas facility. Hepatic and plasma vitellogeni