Experimental assessment of cyto- and pulmonary toxicity of lead oxide nanoparticles after chronic inhalation exposure

Introduction. Respiratory diseases caused by the effects of industrial factors account for a significant proportion of the occupational morbidity among workers in a number of industrial professions. Studying the effects of lead oxide nanoparticles on the respiratory system of rats in a chronic inhalation experiment is an important step in elucidating mechanisms of their cyto- and pulmonary toxicity.

The study aims to evaluate pulmonary and cytotoxic effects of lead oxide nanoparticles following an 8-month chronic inhalation exposure in an in vivo model.

Materials and methods. The authors performed the study on female Wistar rats. The experimental group received PbO nanoparticles (18.2±4.2 nm, 0.215 mg/m³) by inhalation (nose only) for 8 months. The toxicity assessment included respiratory function, cytology and immunology of bronchoalveolar lavage, lung histology, and expression of GSTM1, GSTP1, and SOD2 genes in lung tissue. The researchers conducted statistical data processing using the Student's t-test with the Bonferroni correction and the Mann–Whitney test; the differences were considered significant at p<0.05.

Results. Chronic inhalation exposure to lead oxide nanoparticles caused complex respiratory damage in the animals. We observed cytotoxic effects including pronounced inflammation (neutrophilia, increased N/AM ratio), suppression of phagocytic activity, and downregulation of antioxidant defense genes (GSTM1, GSTP1, SOD2). Histological changes in lung tissue indicate a disruption in the structural organization of the respiratory system.

Limitations. Chronic inhalation exposure of lead oxide nanoparticles was performed using only one concentration of the substance. Another limitation was that the model for the study was rats of the same species and sex. Additional studies are needed to evaluate dose-dependent effects and sexual sensitivity. In addition, the authors assessed the function of external respiration using indirect plethysmography using the integral Penh index, therefore, the data are preliminary and are not definitive evidence of functional disorders.

Conclusion. Chronic inhalation exposure to lead oxide nanoparticles caused multiple adverse changes in the respiratory system of animals at the molecular, cellular, and organ levels.

Ethics. The study was conducted in accordance with the requirements of the European Convention for the Protection of Vertebrate Animals used for Experimental and other Scientific Purposes (ETS No. 123) and Directive 2010/63/EC of the European Parliament and of the Council of September 22, 2010, on the protection of animals used for scientific purposes. Study approval was provided by the Ethics Committee of the Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers (Protocol No. 4 of July 12, 2022).

Contributions:
Sutunkova M.P. — the concept and design of research, writing the text;
Bateneva V.A. — collection and processing of material, statistical data processing, writing text;
Minigalieva I.A. — concept and design of the study, writing the text;
Petrunina E.M. — collection and processing of material;
Kikot A.M. — collection and processing of material;
Bereza I.A. — collection and processing of material;
Shaikhova D.R. — collection and processing of material;
Shtin T.N. — collection and processing of material;
Tazhigulova A.V. — collection and processing of material, statistical data processing, writing text;
Labzova A.K. — collection and processing of material;
Ivashchenko M.A. — collection and processing of material;
Shelomentsev I.G. — collection and processing of the material.

Funding. The study had no funding.

Conflict of interest. The authors declare no conflict of interest.

Received: 08.06.2026 / Accepted: 18.06.2026 / Published: 27.07.2026

1. Shelomentsev I.G., Gomzikova E.A. Prospects of analyzing of nanoparticles in the composition of aerosol by the method of electron microscopy. Gigiena i sanitariya. 2023; 102(3): 259–264. https://doi.org/10.47470/0016-9900-2023-102-3-259-264 (in Russian).

2. Byrne J.D., Baugh J.A. The significance of nanoparticles in particle-induced pulmonary fibrosis. Mcgill J. Med. 2008; 11 (1): 43–50. https://clck.ru/3UJoYW

3. Dumková J., Smutná T., Vrlíková L., Le Coustumer P., Večeřa Z., Dočekal B. et al. Sub-chronic inhalation of lead oxide nanoparticles revealed their broad distribution and tissue-specific subcellular localization in target organs. Part. Fibre Toxicol. 2017; 14(1): 55. https://doi.org/10.1186/s12989-017-0236-y

4. Balali-Mood M., Naseri K., Tahergorabi Z., Khazdair M.R., Sadeghi M. Toxic mechanisms of five heavy metals: Mercury, lead, chromium, cadmium, and arsenic. Front Pharmacol. 2021; 12: 643972. https://doi.org/10.3389/fphar.2021.643972

5. Rocha A., Trujillo K.A. Neurotoxicity of low-level lead exposure: History, mechanisms of action, and behavioral effects in humans and preclinical models. Neurotoxicology. 2019; 73: 58–80. https://doi.org/10.1016/j.neuro.2019.02.021

6. Chen Z., Huo X., Chen G., Luo X., Xu X. Lead (Pb) exposure and heart failure risk. Environ. Sci. Pollut. Res. Int. 2021; 28 (23): 28833–47. https://doi.org/10.1007/s11356-021-13725-9

7. Adamcakova-Dodd A., Stebounova L.V., Kim J.S., Vorrink S.U., Ault A.P., O'Shaughnessy P.T. et al. Toxicity assessment of zinc oxide nanoparticles using sub-acute and sub-chronic murine inhalation models. Part Fibre Toxicol. 2014; 11: 15. https://doi.org/10.1186/1743-8977-11-15

8. Kornberg T.G., Stueckle T.A., Antonini J.A., Rojanasakul Y., Castranova V., Yang Y. et al. Potential toxicity and underlying mechanisms associated with pulmonary exposure to iron oxide nanoparticles: Conflicting literature and unclear risk. Nanomaterials (Basel). 2017; 7(10): 307. https://doi.org/10.3390/nano7100307

9. Abedinloo R., Parvari R., Cheraghi Z., Assari M.J. Evaluating the effectiveness of personal protective equipment against engineered nanomaterials: A systematic review. Toxicol. Ind. Health. 2025; 41(5–6): 327–345. https://doi.org/10.1177/07482337251336897

10. Minigalieva I.A., Bateneva V.A., Shabardina L.V., Sutunkova Ju.M., Nikogosyan K.M., Shelomentsev I.G. Assessment of subacute toxicity of lead oxide nanoparticles during inhalation exposure (experimental study). Toksikologicheskiy vestnik. 2025; 33(3): 149–57. https://doi.org/10.47470/0869-7922-2025-33-3-149-157 (in Russian).

11. Nartsissov R.P. Application of p-nitrotetrazolium violet for quantitative cytochemistry of human lymphocyte dehydrogenases. Arkhiv Anatomii, Gistologii i Embriologii. 1969; 56(5): 85–91. https://elibrary.ru/qjbaad (in Russian).

12. Amromina A.M., Shaikhova D.R., Bereza I.A., Tazhigulova A.V., Minigalieva I.A., Solovyeva S.N. et al. Some neurotoxic effects of lead nanoparticles on NMDA glutamate receptor gene expression and behavioral responses in Wistar rats. Gigiena i sanitariya. 2022; 101(12): 1581–1587. https://doi.org/10.47470/0016-9900-2022-101-12-1581-1587 (in Russian).

13. Arian M., Soleimani M. Practical calculation of mean, pooled variance, variance, and standard deviation, in meta-analysis studies. Nurs. Pract. Today. 2020; 7(1): 5–11. https://doi.org/10.18502/npt.v7i1.2294

14. Privalova L.I., Katsnelson B.A., Osipenko A.B., Yushkov B.N., Babushkina L.G. Response of a phagocyte cell system to products of macrophage breakdown as a probable mechanism of alveolar phagocytosis adaptation to deposition of particles of different cytotoxicity. Environ. Health Perspect. 1980; 35: 205–218. https://doi.org/10.1289/ehp.8035205

15. Katsnelson B.A., Privalova L.I., Kislitsina N.S., Podgaiko G.A. Correlation between cytotoxicity and fibrogenicity of silicosis-inducing dusts. Med. Lav. 1984; 75(6): 450–462. https://elibrary.ru/xmasku

16. Lebedová J., Nováková Z., Večeřa Z., Buchtová M., Dumková J., Dočekal B. et al. Impact of acute and subchronic inhalation exposure to PbO nanoparticles on mice. Nanotoxicology. 2018; 12(4): 290–304. https://doi.org/10.1080/17435390.2018.1438679

17. Bláhová L., Nováková Z., Večeřa Z., Vrlíková L., Dočekal B., Dumková J. et al. The effects of nano-sized PbO on biomarkers of membrane disruption and DNA damage in a sub-chronic inhalation study on mice. Nanotoxicology. 2020; 14(2): 214–231. https://doi.org/10.1080/17435390.2019.1685696

18. Katsnelson, B.A., Privalova L.I., Sutunkova M.P., Minigalieva I.A., Gurvich V.B., Shur V.Y. et al. Experimental research into metallic and metal oxide nanoparticle toxicity in vivo. In: Yan B., Zhou H., Gardea-Torresdey J., eds. Bioactivity of Engineered Nanoparticles. Nanomedicine and Nanotoxicology. Singapore: Springer; 2017. https://doi.org/10.1007/978-981-10-5864-6_11