Assessment of Ecotoxicity of Copper, Nickel, and Zinc Nanoparticles on the Basis of Biological Indicators of Chernozems
Ecotoxicity of nanoparticles (50–100 nm) of Cu, Ni, and Zn was assessed from changes in the biological indicators of an ordinary chernozem (Haplic Chernozem (Loamic)) in Rostov-on-Don in the laboratory model experiment with incubation of the soil samples with nanopowders of these elements added to the soils in concentrations of 100, 1000, and 10 000 mg/kg. The biological indicators were determined in 10, 30, and 90 days after the soil contamination. The addition of Cu, Ni, and Zn nanoparticles led to a decrease in the total number of bacteria, abundance of Azotobacter bacteria, catalase and dehydrogenase activities, and germination and length of the roots of radish seeds. Reliable cases of hormesis were not detected. Nanoparticles of Cu and Zn showed a higher toxicity than Ni nanoparticles, which is inconsistent with the hypothesis, according to which the toxicity of nanoparticles depends only on their size and does not depend on the chemical nature of an element. According to the integral indicator of the biological state of the soil, the greatest toxicity of Cu, Ni, and Zn nanoparticles was observed on the 30th day after the pollution.