title: The hazard assessment of nanostructured CeO₂-based mixed oxides on the zebrafish Danio rerio under environmentally relevant UV-A exposure.
abstract: The effect of nanomaterials on biota under realistic environmental conditions is an important question. However, there is still a lack of knowledge on how different illumination conditions alter the toxicity of some photocatalytic nanomaterials. We have investigated how environmentally relevant UV-A exposure (intensity 8.50 ± 0.61 W/m(2), exposure dose 9.0J/cm(2)) affected the toxicity of cerium oxide (CeO2)-based nanostructured materials to the early-life stages of zebrafish Danio rerio. Pure cerium oxide (CeO2), copper-cerium (CuO-CeO2) (with a nominal 10, 15 and 20 mol.% CuO content), cerium-zirconium (CeO2-ZrO2) and nickel and cobalt (Ni-Co) deposited over CeO2-ZrO2 were tested. It was found that under both illumination regimes, none of the tested materials affected the normal development or induced mortality of zebrafish early-life stages up to 100mg/L. Only in the case of CuO-CeO2, the growth of larvae was decreased (96 h LOEC values for CuCe10, CuCe15 and CuCe20 were 50, 50 and 10mg/L, respectively). To conclude, CeO2-based nanostructured materials are not severely toxic to zebrafish and environmentally relevant UV-A exposure does not enhance their toxicity.
authors.affiliation: National Institute of Chemistry, Laboratory for Environmental Sciences and Engineering, Hajdrihova 19, SI-1001 Ljubljana, Slovenia; University of Ljubljana, Biotechnical Faculty, Department of Biology, Večna pot 111, SI-1000 Ljubljana, Slovenia. Electronic address: anita.jemec@bf.uni-lj.si.
authors.forename: Anita
authors.initials: A
authors.lastname: Jemec
authors.affiliation: National Institute of Chemistry, Laboratory for Environmental Sciences and Engineering, Hajdrihova 19, SI-1001 Ljubljana, Slovenia.
authors.forename: Petar
authors.initials: P
authors.lastname: Djinović
authors.affiliation: National Institute of Chemistry, Laboratory for Environmental Sciences and Engineering, Hajdrihova 19, SI-1001 Ljubljana, Slovenia.
authors.forename: Ilja Gasan Osojnik
authors.initials: IG
authors.lastname: Crnivec
authors.affiliation: National Institute of Chemistry, Laboratory for Environmental Sciences and Engineering, Hajdrihova 19, SI-1001 Ljubljana, Slovenia.
authors.forename: Albin
authors.initials: A
authors.lastname: Pintar
mesh_terms: D000818:Animals; D002563:Cerium / Q000633:toxicity*; D007814:Larva; D049329:Nanostructures / Q000633:toxicity*; D018570:Risk Assessment; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015027:Zebrafish
chemical_list: D014874:Water Pollutants, Chemical; D002563:Cerium; C030583:ceric oxide
keywords: Nickel cobalt nanocrystalline catalysts; UV-A phototoxicity; UV-shielding, zebrafish