title: Sorption of isoflavones to river sediment and model sorbents and outcomes for larval fish exposed to contaminated sediment.
abstract: Isoflavones are compounds whose presence in the aquatic environment is increasingly recognized and may be of concern due to their potential to act as endocrine disruptors. Sorption to particles may be a relevant removal mechanism for isoflavones. This work investigated the influence of pH, ionic strength, and sediment composition on sorption of genistein and daidzein, two key isoflavones, using sorption isotherms and edges. The effect of sorbed isoflavones on the survival, growth, and predator avoidance performance of larval fathead minnows (Pimephales promelas) was assessed. Sorption to goethite and kaolinite was pH-dependent, with a maximum near pH 7 for both compounds. Sorption to montmorillonite was ionic-strength dependent but largely pH-independent. Overall, sorption to sediments is likely to sequester less than 5% of isoflavones in a discharge. No statistically significant effects were observed for larvae exposed to sorbed isoflavones, suggesting that sorption to sediments reduces exposure to isoflavones.
authors.affiliation: Water Resources Science Graduate Program, University of Minnesota, 1985 Buford Ave., Saint Paul, MN 55108, United States.
authors.forename: Megan M
authors.initials: MM
authors.lastname: Kelly
authors.affiliation: Aquatic Toxicology Laboratory, Saint Cloud State University, 720 4th Ave. South, Saint Cloud, MN 56301, United States.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Rearick
authors.affiliation: Faculty of Science and Technology, University of Stavanger, 4036 Stavanger, Norway.
authors.forename: Camilla G
authors.initials: CG
authors.lastname: Overgaard
authors.affiliation: Aquatic Toxicology Laboratory, Saint Cloud State University, 720 4th Ave. South, Saint Cloud, MN 56301, United States.
authors.forename: Heiko L
authors.initials: HL
authors.lastname: Schoenfuss
authors.affiliation: Water Resources Science Graduate Program, University of Minnesota, 1985 Buford Ave., Saint Paul, MN 55108, United States; Department of Civil Engineering, University of Minnesota, 500 Pillsbury Dr. SE, Minneapolis, MN 55455, United States. Electronic address: arnol032@umn.edu.
authors.forename: William A
authors.initials: WA
authors.lastname: Arnold
mesh_terms: D000327:Adsorption; D000818:Animals; D001546:Bentonite / Q000737:chemistry; D003530:Cyprinidae / Q000502:physiology; D004924:Escape Reaction / Q000187:drug effects; D019833:Genistein / Q000737:chemistry* / Q000633:toxicity; D019015:Geologic Sediments / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D058085:Iron Compounds / Q000737:chemistry; D007529:Isoflavones / Q000737:chemistry* / Q000633:toxicity; D007616:Kaolin / Q000737:chemistry; D007814:Larva / Q000187:drug effects / Q000502:physiology; D008903:Minerals / Q000737:chemistry; D009994:Osmolar Concentration; D045483:Rivers; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000633:toxicity
chemical_list: D058085:Iron Compounds; D007529:Isoflavones; D008903:Minerals; D014874:Water Pollutants, Chemical; D001546:Bentonite; C094886:goethite; D007616:Kaolin; C007768:formononetin; C004742:daidzein; D019833:Genistein
keywords: Daidzein; Genistein; Isoflavones; Larval exposure; Phytoestrogens; Sorption