Jemec A, Djinović P, Osojnik Črnivec IG, Pintar A
[ pdf ] [ site ] Science of The Total Environment, 2015

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/m², exposure dose 9.0 J/cm²) 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–ZrO₂were 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 100 mg/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 10 mg/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.