title: Phthalate ester leachates in aquatic mesocosms: implications for ecotoxicity studies of endocrine disrupting compounds.
abstract: Aquatic mesocosm experiments have become common throughout the fields of ecology and ecotoxicology. Mesocosm containers are often composed of plastic materials as these are lighter and cheaper than steel cattle tanks. Plastics may contain phthalate esters which may leach from containers, potentially confounding experiments via toxicity or endocrine disruption. The objective of this experiment was to determine the extent to which plastic containers (="tanks") used for mesocosms leach phthalates, and if there are significant differences between tank types and phthalate profiles. We investigated four tank types: fiberglass, polyethylene, poly-vinyl chloride, and polyethylene tanks containing an established aquatic community. We measured six common phthalate esters in water samples collected from each tank every 2 weeks for 8 weeks. There was a significant effect of tank type, time, and time x type interactions on phthalate ester concentrations. Di-(2-ethylhexyl) phthalate was the predominant congener measured in all samples. Fiberglass tanks had greater concentrations of dimethyl phthalate compared to other tank types (more than 600x larger concentration), but no other differences in phthalate profiles among tank types were evident. In addition, tanks with established communities had much higher concentrations of most phthalates at the 6 and 8 week timepoints. Our study confirms that mesocosm tanks of different materials leach phthalates starting immediately after they are filled and continuing for at least 8 weeks, but do so at different rates. Future ecotoxicity experiments should consider the potentially confounding effects of phthalates that may leach from tanks used in experimental mesocosms.
authors.affiliation: The Institute of Environmental and Human Health, Department of Environmental Toxicology, Box 41163, Texas Tech University, Lubbock, TX 79409, United States. Electronic address: scott.weir@tiehh.ttu.edu.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Weir
authors.affiliation: The Institute of Environmental and Human Health, Department of Environmental Toxicology, Box 41163, Texas Tech University, Lubbock, TX 79409, United States.
authors.forename: Kimberly J
authors.initials: KJ
authors.lastname: Wooten
authors.affiliation: The Institute of Environmental and Human Health, Department of Environmental Toxicology, Box 41163, Texas Tech University, Lubbock, TX 79409, United States.
authors.forename: Philip N
authors.initials: PN
authors.lastname: Smith
authors.affiliation: The Institute of Environmental and Human Health, Department of Environmental Toxicology, Box 41163, Texas Tech University, Lubbock, TX 79409, United States.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Salice
mesh_terms: D000818:Animals; D002417:Cattle; D004051:Diethylhexyl Phthalate / Q000032:analysis / Q000737:chemistry / Q000633:toxicity; D052244:Endocrine Disruptors / Q000032:analysis* / Q000737:chemistry / Q000633:toxicity; D004952:Esters; D005898:Glass / Q000737:chemistry; D010795:Phthalic Acids / Q000032:analysis* / Q000737:chemistry / Q000633:toxicity; D010969:Plastics / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry / Q000633:toxicity
chemical_list: D052244:Endocrine Disruptors; D004952:Esters; D010795:Phthalic Acids; D010969:Plastics; D014874:Water Pollutants, Chemical; C009753:fiberglass; C024629:dimethyl phthalate; D004051:Diethylhexyl Phthalate
keywords: Amphibians; Aquatic communities; Aquatic ecotoxicology; Plasticizers