Impact of acute and subchronic inhalation exposure to PbO nanoparticles on mice

Abstract

Lead nanoparticles (NPs) are released into air from metal processing, road transport or combustion processes. Inhalation exposure is therefore very likely to occur. However, even though the effects of bulk lead are well known, there is limited knowledge regarding impact of Pb NPs inhalation. This study focused on acute and subchronic exposures to lead oxide nanoparticles (PbO NPs). Mice were exposed to PbO NPs in whole body inhalation chambers for 4-72 h in acute experiment (4.05 × 10 PbO NPs/cm), and for 1-11 weeks in subchronic experiment (3.83 × 10 particles/cm in lower and 1.93 × 10 particles/cm in higher exposure group). Presence of NPs was confirmed in all studied organs, including brain, which is very important considering lead neurotoxicity. Lead concentration gradually increased in all tissues depending on the exposure concentration and duration. The most burdened organs were lung and kidney, however liver and brain also showed significant increase of lead concentration during exposure. Histological analysis documented numerous morphological alterations and tissue damage, mainly in lung, but also in liver. Mild pathological changes were observed also in kidney and brain. Levels of glutathione (reduced and oxidized) were modulated mainly in lung in both, acute and subchronic exposures. Increase of lipid peroxidation was observed in kidney after acute exposure. This study characterized impacts of short to longer-term inhalation exposure, proved transport of PbO NPs to secondary organs, documented time and concentration dependent gradual increase of Pb concentration and histopathological damage in tissues.

Macrophage-Mediated Tissue Response Evoked By Subchronic Inhalation of Lead Oxide Nanoparticles Is Associated With The Alteration of Phospholipases C And Cholesterol Transporters

“…The concentration of Pb in the lung as the primary target organ was practically identical to the kidney. We have seen such similar accumulation of Pb in the lung and kidney also in our previous study at the end of 11 weeks of inhalation a higher concentration of PbO NPs [43]. In current study, the Pb concentration in the liver and also the spleen was about 3.5-fold lower compared to the lung and kidney.…”

“…When nanoparticles are not phagocytosed, they are deposited into the lung cells. Following inhalation of PbO nanoparticles, we observed the largest amount of nanoparticles in type I pneumocytes, which is consonant with our previous ndings on PbO NPs [43].…”

“…In current study, the Pb concentration in the liver and also the spleen was about 3.5-fold lower compared to the lung and kidney. In our previous study [43], where only liver and not spleen was analyzed, such drop was about 4-fold.…”

Toxicity of metallic nanoparticles in the central nervous system

“…Translocation from the lungs to the secondary organs, such as the brain, was also reported for lead oxide NP (PbO NPs) after acute or subchronic PbO NPs inhalation by female mice. Inhaled PbO NPs caused mild pathological alterations in the hippocampus area [105].…”

Minimal Risk Level Derivation for Cadmium: Acute and Intermediate Duration Exposures

“…As in metal fume fever, initial symptoms of cadmium fume overexposure were usually mild pulmonary edema that rapidly progressed to severe edema and pneumonitis [9,10]. Similarly, studies have reported that acute exposure to cadmium can cause lung damage in animals [11][12][13][14][15].…”