Pathway-based approaches for assessment of real-time exposure to an estrogenic wastewater treatment plant effluent on fathead minnow reproduction.
Wastewater treatment plant (WWTP) effluents are known contributors of chemical mixtures into the environment. Of particular concern are endocrine-disrupting compounds, such as estrogens, which can affect the hypothalamic-pituitary-gonadal axis function in exposed organisms. The present study examined reproductive effects in fathead minnows exposed for 21 d to a historically estrogenic WWTP effluent. Fathead minnow breeding pairs were held in control water or 1 of 3 effluent concentrations (5%, 20%, and 100%) in a novel onsite, flow-through system providing real-time exposure. The authors examined molecular and biochemical endpoints representing key events along adverse outcome pathways linking estrogen receptor activation and other molecular initiating events to reproductive impairment. In addition, the authors used chemical analysis of the effluent to construct a chemical-gene interaction network to aid in targeted gene expression analyses and identifying potentially impacted biological pathways. Cumulative fecundity was significantly reduced in fish exposed to 100% effluent but increased in those exposed to 20% effluent, the approximate dilution factor in the receiving waters. Plasma vitellogenin concentrations in males increased in a dose-dependent manner with effluent concentration; however, male fertility was not impacted. Although in vitro analyses, analytical chemistry, and biomarker responses confirmed the effluent was estrogenic, estrogen receptor agonists were unlikely the primary driver of impaired reproduction. The results provide insights into the significance of pathway-based effects with regard to predicting adverse reproductive outcomes.
ORISE Research Participation Program, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, US Environmental Protection Agency, Duluth, Minnesota, USA.|Integrated Biosciences Graduate Program, University of Minnesota-Duluth, Duluth, Minnesota, USA.
Jenna E
JE
Cavallin
Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, US Environmental Protection Agency, Duluth, Minnesota, USA.
Kathleen M
KM
Jensen
Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, US Environmental Protection Agency, Duluth, Minnesota, USA.
Michael D
MD
Kahl
Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, US Environmental Protection Agency, Duluth, Minnesota, USA.
Daniel L
DL
Villeneuve
Toxic Substances Hydrology Program, US Geological Survey, Grand Rapids, Minnesota, USA.
Kathy E
KE
Lee
Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, University of Minnesota-Water Resources Center, US Environmental Protection Agency, Duluth, Minnesota, USA.
Anthony L
AL
Schroeder
Western Lake Superior Sanitary District, Duluth, Minnesota, USA.
Joe
J
Mayasich
Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, US Environmental Protection Agency, Duluth, Minnesota, USA.
Evan P
EP
Eid
Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, US Environmental Protection Agency, Duluth, Minnesota, USA.
Krysta R
KR
Nelson
ORISE Research Participation Program, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, US Environmental Protection Agency, Duluth, Minnesota, USA.
Rebecca Y
RY
Milsk
ORISE Research Participation Program, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, US Environmental Protection Agency, Duluth, Minnesota, USA.
Brett R
BR
Blackwell
Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, US Environmental Protection Agency, Duluth, Minnesota, USA.
Jason P
JP
Berninger
Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, US Environmental Protection Agency, Duluth, Minnesota, USA.
Carlie A
CA
LaLone
Badger Technical Services, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, US Environmental Protection Agency, Duluth, Minnesota, USA.
Chad
C
Blanksma
Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, US Environmental Protection Agency, Duluth, Minnesota, USA.
Terri
T
Jicha
Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, US Environmental Protection Agency, Duluth, Minnesota, USA.
Colleen
C
Elonen
Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, US Environmental Protection Agency, Duluth, Minnesota, USA.
Rodney
R
Johnson
Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, US Environmental Protection Agency, Duluth, Minnesota, USA.
Gerald T
GT
Ankley
D000818:Animals; D003530:Cyprinidae; D052244:Endocrine Disruptors / Q000032:analysis / Q000633:toxicity*; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D006066:Gonads / Q000187:drug effects / Q000473:pathology; D008297:Male; D012098:Reproduction / Q000187:drug effects; D013256:Steroids / Q000096:biosynthesis; D014819:Vitellogenins / Q000096:biosynthesis; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*; D060753:Water Quality
D052244:Endocrine Disruptors; D013256:Steroids; D014819:Vitellogenins; D062065:Wastewater; D014874:Water Pollutants, Chemical
Estrogens; Fish; Reproduction; Wastewater treatment plant