Suchergebnisse

Female white rats were exposed during up to 6 months 5 times a week, 4 hr per day in a "nose only" inhalation device to an aerosol containing predominantly submicron (nanoscale included) particles of amorphous silica in the concentration 2.6±0.6 or 10.6±2.1 mg/m3. In an auxiliary experiment with a single-shot intratracheal instillation of these particles, it was shown that they induced a pulmonary cell response comparable with that to highly cytotoxic and fibrogenic standard quartz powder DQ12. However, in the long-term inhalation test, the studied aerosol proved to be of very low systemic toxicity and fibrogenicity. This paradox may be explained by low SiO2 retention in lungs and other organs due to a relatively high in vivo solubility of these nanoparticles. Nevertheless, their genotoxic action and transnasal penetration into the brain should make one give a cautious overall assessment of this aerosol as an occupational or environmental hazard. © Published under licence by IOP Publishing Ltd. ; Government Council on Grants, Russian Federation ; Ministry of Science and Higher Education of the Russian Federation: 3.9534.2017/8.9 ; The research was partially supported by the Ministry of Science and Higher Education of the Russian Federation (project 3.9534.2017/8.9) and by Government of the Russian Federation (Act 211, Agreement 02.A03.21.0006). The equipment of the Ural Centre for Shared Use "Modern Nanotechnology" UrFU was used.

Nanoparticles of metals and their oxides (Me-NPs) are of special interest in the light of health risks assessment and management, because, along with engineered Me-NPs, there exists usually a substantial fraction of nanoscale ("ultrafine") particles of the same substances within the particle size distribution of condensation aerosols generated by arc-welding, metallurgical, and some chemical technologies. The nonspecific responses of the organism to the impact of Me-NP included: changes in the cytological and some biochemical characteristics of the bronchoalveolar lavage fluid caused by the deposition of particles in the lower airways, various manifestations of systemic toxicity including significant damage to the liver and kidneys, moderate neurological disturbances associated with possible penetration of Me-NP into the brain from the blood as well as from the nasal mucous membrane along the olfactory pathway, a paradoxically low manifestation of pulmonary pathology due to low chronic retention of nanoparticles in the lungs, and a genotoxic effect on the organism level. The toxicity and even genotoxicity of Me-NPs can be significantly attenuated by adequately composed combinations of some bioactive agents in innocuous doses. © Published under licence by IOP Publishing Ltd. ; Government Council on Grants, Russian Federation ; Ministry of Science and Higher Education of the Russian Federation: 3.9534.2017/8.9 ; The research was partially supported by the Ministry of Science and Higher Education of the Russian Federation (project 3.9534.2017/8.9) and by Government of the Russian Federation (Act 211, Agreement 02.A03.21.0006). The equipment of the Ural Centre for Shared Use "Modern Nanotechnology" UrFU was used.