Comparative estimation of ecotoxicity of nano- and microparticles of CuO, ZnO, NiO, Co₃O₄ by the integral biological indicator of soil state

Since the beginning of the twenty first century, nanoparticles have been widely used in medicine, industry, and other scientific studies. Significant use of nanoparticles in everyday life and industry leads to their inevitable release into the environment. In this regard, nanoparticles have been qualified as one of the new types of pollutants. The aim of this study is to evaluate the effect of micro- and nanoparticles of CuO, ZnO, NiO, and Co₃O₄ on the biological properties of ordinary Chernozem. The studied substances were applied to the soil in 3, 10, and 30 background concentrations. The total number of bacteria, the Azotobacter sp. abundance, activity of catalase and dehydrogenases, radish length and germination rate were chosen as the studied biological indicators. The present study investigated the most dangerous nanoparticles to the soil were ZnO and Co₃O₄, and the least toxic—NiO, CuO. Nanoparticles of the studied oxides are more ecotoxic than their microparticles, which indicates a greater danger of getting the studied oxides in the nanoform into the soil.