title: The uptake of ZnO and CuO nanoparticles in the water-flea Daphnia magna under acute exposure scenarios.
abstract: In this study the uptake of ZnO and CuO nanoparticles by Daphnia magna was tested. Daphnids were exposed during 48 h to acute concentrations of the nanoparticles and corresponding metal salts. The Daphnia zinc and copper concentration was measured and the nanoparticles were localized using electron microscopy. The aggregation and dissolution in the medium was characterized. A fast dissolution of ZnO in the medium was observed, while most CuO formed large aggregates and only a small fraction dissolved. The Daphnia zinc concentration was comparable for the nanoparticles and salts. Contrarily, a much higher Daphnia copper concentration was observed in the CuO exposure, compared to the copper salt. CuO nanoparticles adsorbed onto the carapace and occurred in the gut but did not internalize in the tissues. The combined dissolution and uptake results indicate that the toxicity of both nanoparticle types was caused by metal ions dissolved from the particles in the medium.
authors.affiliation: Systemic Physiological and Ecotoxicological Research, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium. Electronic address: nathalieadam12@gmail.com.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Adam
authors.affiliation: Electron Microscopy for Materials Science (EMAT), Department of Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Leroux
authors.affiliation: Physiology and Biochemistry of Domestic Animals, Department of Veterinary Sciences, University of Antwerp, Universiteitslaan 1, 2610 Wilrijk, Belgium.
authors.forename: Dries
authors.initials: D
authors.lastname: Knapen
authors.affiliation: Electron Microscopy for Materials Science (EMAT), Department of Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium.
authors.forename: Sara
authors.initials: S
authors.lastname: Bals
authors.affiliation: Systemic Physiological and Ecotoxicological Research, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium.
authors.forename: Ronny
authors.initials: R
authors.lastname: Blust
mesh_terms: D000818:Animals; D003300:Copper / Q000378:metabolism* / Q000633:toxicity; D003621:Daphnia / Q000378:metabolism*; D053768:Metal Nanoparticles / Q000032:analysis* / Q000633:toxicity; D023382:Toxicity Tests, Acute; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*; D015034:Zinc Oxide / Q000378:metabolism* / Q000633:toxicity
chemical_list: D014874:Water Pollutants, Chemical; D003300:Copper; D015034:Zinc Oxide; C030973:cupric oxide
keywords: Aggregation; Copper; Dissolution; Electron microscopy; Zinc