title: Laboratory analyses of the potential toxicity of sediment-associated polydimethylsiloxane to benthic macroinvertebrates.
abstract: Polydimethylsiloxane (PDMS) is widely used in a number of industrial processes and consumer products that result in down-the-drain disposal. The log p value for the PDMS used in the present study was 10, and the vapor pressure and water solubility values were below detection limits. These physicochemical characteristics and a measured degradation rate of 3% after six months in moist soils suggest that PDMS may accumulate in aquatic sediments. Sediment toxicity tests with the amphipod Hyalella azteca and with larvae of the midge Chironomus tentans were used to assess the potential for toxicity of PDMS-amended sediments to benthic invertebrates in short-term (10-d) and whole-life-cycle (28 d for H. azteca, 50-65 d for C. tentans) exposures. Endpoints for short-term tests included survival and growth, while life-cycle assays considered survival, growth, reproduction, and, for C. tentans only, emergence. Short-term and life-cycle exposures to concentrations of > or = 1,000 mg PDMS/kg sediment (dry wt) indicated that PDMS will not reduce survival, growth, or reproduction in H. azteca or C. tentans.
authors.affiliation: Department of Zoology, National Food Safety and Toxicology Center, Institute for Environmental Toxicology, Michigan State University, East Lansing 48824, USA. kshenry@dow.com
authors.forename: K S
authors.initials: KS
authors.lastname: Henry
authors.forename: W H
authors.initials: WH
authors.lastname: Wieland
authors.forename: D E
authors.initials: DE
authors.lastname: Powell
authors.forename: J P
authors.initials: JP
authors.lastname: Giesy
mesh_terms: D000818:Animals; D002683:Chironomidae; D020099:Coated Materials, Biocompatible / Q000633:toxicity*; D003445:Crustacea; D004129:Dimethylpolysiloxanes / Q000633:toxicity*; D019015:Geologic Sediments / Q000737:chemistry*; D007814:Larva / Q000254:growth & development; D012098:Reproduction / Q000187:drug effects; D012828:Silicones / Q000633:toxicity*; D012995:Solubility; D016019:Survival Analysis; D014835:Volatilization
chemical_list: D020099:Coated Materials, Biocompatible; D004129:Dimethylpolysiloxanes; D012828:Silicones; C013830:baysilon