title: Changes in estrogen/anti-estrogen activities in ponded secondary effluent.
abstract: Total estrogenic activity, measured using the yeast estrogen screen reporter gene bioassay, decreased from 60 pM (equivalent 17alpha-ethinylestradiol concentration) to an estimated 1.4 pM during a 24-hour period in which secondary effluent was held in a shallow infiltration basin. Over the same period, anti-estrogenic activity, measured as an equivalent concentration of tamoxifen, increased from 35 to 260 nM, suggesting that antagonists produced during secondary effluent storage played a role in the apparent loss of estrogenic activity. Androgenic activity, measured over the same 24-hour period using the yeast androgen screen, was near or below the method detection limit (0.7 pM as testosterone). However, the same pond samples were clearly anti-androgenic. When whole-sample extracts were separated via adsorption and stepwise elution in alcohol/water solutions consisting of 20, 40 and 100% ethanol, the sum of estrogenic activities in derived fractions was always lower than the measured estrogenic activity in the whole-sample extracts. Summed anti-estrogenic activities in the same fractions, however, always exceeded values for corresponding whole-sample extracts. Results reinforce the importance of sample preparation steps (concentration of organics followed by estrogen/anti-estrogen separation) when measuring endocrine-related activities in chemically complex samples such as wastewater effluent. The potential complexity of relationships among estrogens, anti-estrogens and matrix organics suggests that additive models are of questionable validity for estimating whole-sample estrogenic activity from measurements involving sample fractions.
authors.affiliation: Department of Chemical and Environmental Engineering, The University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Otakuye
authors.initials: O
authors.lastname: Conroy
authors.forename: A Eduardo
authors.initials: AE
authors.lastname: Sáez
authors.forename: David
authors.initials: D
authors.lastname: Quanrud
authors.forename: Wendell
authors.initials: W
authors.lastname: Ela
authors.forename: Robert G
authors.initials: RG
authors.lastname: Arnold
mesh_terms: D000728:Androgens / Q000032:analysis / Q000633:toxicity; D001130:Arizona; D001681:Biological Assay; D004305:Dose-Response Relationship, Drug; D004784:Environmental Monitoring / Q000379:methods*; D020847:Estrogen Receptor Modulators / Q000032:analysis* / Q000633:toxicity; D004968:Estrogens, Non-Steroidal / Q000032:analysis* / Q000633:toxicity; D011960:Receptors, Estrogen / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D020845:Selective Estrogen Receptor Modulators / Q000494:pharmacology; D012722:Sewage / Q000032:analysis*; D013629:Tamoxifen / Q000494:pharmacology; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000633:toxicity
chemical_list: D000728:Androgens; D020847:Estrogen Receptor Modulators; D004968:Estrogens, Non-Steroidal; D011960:Receptors, Estrogen; D020845:Selective Estrogen Receptor Modulators; D012722:Sewage; D014874:Water Pollutants, Chemical; D013629:Tamoxifen