Zdrojový dokument:Scientific papers of the University of Pardubice. Series A, Faculty of Chemical Technology. 24/2018
ISSN:1211-5541
Abstrakt:
Composition of the exposure media always affects the properties of nanomaterials. In
terrestrial ecotoxicology, the complex nature of the soil highly complicates the
prediction of impacts of pollutants upon the environment. In our study, less complex
agar-based exposure medium had been therefore used instead a soil. An acute toxicity
of zinc oxide nanoparticle (ZnO-NPs, mean particle size diameter of 10 nm) powder and
of water-soluble salt of zinc (ZnCl2) to annelid Enchytraeus crypticus were tested, while
agar-based exposure medium was modified with two sources of humic acids (sodium
humate, peat) in order to study the influence of soil component and its form on toxicity
of zinc. In the case of ZnCl2, an addition of humic acid always reduced the toxicity. The
respective values of LC50 were 13.2, 28.8, and 191 mg kg–1 for pure agar, agar with
sodium humate, and agar with peat, respectively. On the contrary, the addition of
sodium humate into an agar increased toxicity of ZnO NPs and the reduction in toxicity
was observed only for the addition of a peat. The corresponding LC50 values then were
43.5 (pure agar), 15.8 (agar with sodium humate), and 304 (agar with peat) mg kg–1.