title: Elevated concentrations of ethinylestradiol, 17beta-estradiol, and medroxyprogesterone have little effect on reproduction and survival of Ceriodaphnia dubia.
abstract: Wastewater effluent contains synthetic and natural hormones, often in complex mixtures, that may be associated with reproductive abnormalities in fish and other aquatic biota. We exposed the sentinel invertebrate Ceriodaphnia dubia to the natural estrogen 17beta-estradiol (E(2)), a synthetic estrogen, ethinylestradiol (EE(2)), and a synthetic progestin, medroxyprogesterone in a 7-day test. These compounds had no significant effect on reproduction or survival even at 10(6) times the concentrations at which reproductive effects have been documented in several fish species. C. dubia is routinely used for screening the toxicity of wastewater effluent. However, in the standard chronic 7-day exposure the endpoints of survival and reproduction were insensitive to several synthetic and natural vertebrate hormones. The C. dubia 7-day chronic toxicity test is probably not a useful monitoring tool for vertebrate hormones and their pharmaceutical analogs unless other sensitive endpoints such as maturation rates, molt frequency, and offspring sex ratios are incorporated in a practical manner.
authors.affiliation: Department of Physiology, Dartmouth College, Hinman Box 7700, Hanover, NH 03755, USA. James.A.Jukosky@dartmouth.edu
authors.forename: James A
authors.initials: JA
authors.lastname: Jukosky
authors.forename: Mary C
authors.initials: MC
authors.lastname: Watzin
authors.forename: James C
authors.initials: JC
authors.lastname: Leiter
mesh_terms: D000818:Animals; D033361:Cladocera / Q000187:drug effects* / Q000502:physiology; D004958:Estradiol / Q000633:toxicity*; D004997:Ethinyl Estradiol / Q000633:toxicity*; D008525:Medroxyprogesterone / Q000633:toxicity*; D012098:Reproduction / Q000187:drug effects; D036401:Toxicity Tests, Chronic / Q000379:methods; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D004997:Ethinyl Estradiol; D004958:Estradiol; D008525:Medroxyprogesterone