title: Phenanthrene Bioavailability and Toxicity to Daphnia magna in the Presence of Carbon Nanotubes with Different Physicochemical Properties.
abstract: Studies investigating the effect of carbon nanotubes (CNTs) on the bioavailability and toxicity of hydrophobic organic compounds in aquatic environments have generated contradictory results, and the influence of different CNT properties remains unknown. Here, the adsorption of the polycyclic aromatic hydrocarbon phenanthrene (70-735 μg/L) to five types of CNTs exhibiting different physical and chemical properties was studied. The CNTs were dispersed in the presence of natural organic matter (nominally 20 mg/L) in order to increase the environmental relevance of the study. Furthermore, the bioavailability and toxicity of phenanthrene to Daphnia magna in the absence and presence of dispersed CNTs was investigated. Both CNT dispersion and adsorption of phenanthrene appeared to be influenced by CNT physical properties (diameter and specific surface area). However, dispersion and phenanthrene adsorption was not influenced by CNT surface chemical properties (surface oxygen content), under the conditions tested. Based on nominal phenanthrene concentrations, a reduction in toxicity to D. magna was observed during coexposure to phenanthrene and two types of CNTs, while for the others, no influence on phenanthrene toxicity was observed. Based on freely dissolved concentrations, however, an increased toxicity was observed in the presence of all CNTs, indicating bioavailability of CNT-adsorbed phenanthrene to D. magna.
authors.affiliation: Department of Biology, Norwegian University of Science and Technology , Trondheim NO-7491, Norway.
authors.forename: Florian
authors.initials: F
authors.lastname: Zindler
authors.affiliation: Department of Biology, Norwegian University of Science and Technology , Trondheim NO-7491, Norway.
authors.forename: Berit
authors.initials: B
authors.lastname: Glomstad
authors.affiliation: BioTrix, Trondheim NO-7022, Norway.
authors.forename: Dag
authors.initials: D
authors.lastname: Altin
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
authors.forename: Jingfu
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Biology, Norwegian University of Science and Technology , Trondheim NO-7491, Norway.
authors.forename: Bjørn M
authors.initials: BM
authors.lastname: Jenssen
authors.affiliation: SINTEF Materials and Chemistry, Trondheim NO-7465, Norway.
authors.forename: Andy M
authors.initials: AM
authors.lastname: Booth
mesh_terms: D000327:Adsorption; D000818:Animals; D001682:Biological Availability; D003621:Daphnia / Q000187:drug effects*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010616:Phenanthrenes / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D037742:Nanotubes, Carbon; D010616:Phenanthrenes; D014874:Water Pollutants, Chemical