The article presents in an experiment obtained principal results based on repeated low-level inhalation
exposures of laboratory animals (white rats, outbred) to nickel oxide nanoparticles with a diameter of
(23 ± 5) nm, 4 hours a day, 5 times a week for up to 10 months in a «nose only» installation. It was
shown that non-specific body reactions to the action of NiO NPs include: diverse manifestations of systemic
toxicity with a particularly pronounced influence on liver and kidney function, redox balance, damage to
some areas of brain tissue, associated with proven movement of the nanoparticles themselves from the
nasal mucosa along the olfactory tract; some cytological signs of probable development for allergic syndrome;
paradoxically low severity of pulmonary pathology by pneumoconiotic type explained by a small chronic
delay of nanoparticles in the lungs; the genotoxic effect of the organismal level, even at those low levels
of chronic exposure, at which systemic toxicity is rather poorly. Along with that, NiO NPs also induce
phase-stimulation of erythropoiesis, which is relatively specific for the toxic nickel effects.