[Hygienic and toxicological safety assessment of nano- and micro-dispersed manganese oxide (III, IV)].

The findings of the experimental study performed within the preliminary hygienic and toxicological assessment of nanodispersed manganese oxide (III, IV), which was endogastrics administered to white nonlinear mice once, showed that, under acute oral exposure to manganese oxide, nanodispersed particles were 2,6-fold more toxic and cumulative (class 3, according to the oral LD50 values) than dispersed solution with micro-sized particles (0.4-592 microm, class 4). Endogactric exposure to nanodispersed solution of manganese oxide (III, IV) in organisme produced such negative health effects as vasodilation and plethora, pathological inclusions and increased cell aggregation, which increased and became more prevalent with higher doses. The prediction of chronic toxicity parameters demonstrated that threshold and NOAEL doses for nanodispersed solution were 1.6 and 0.26 mg/kg, respectively, which are 2.3 times lower than for finely divided solution of manganese oxide (III, IV).