Assessment of subacute toxicity of lead oxide nanoparticles during inhalation exposure (experimental study)

Introduction. Nanoparticles of various elements, including lead, are produced during high-temperature technological processes in many mining and processing facilities. Once in the atmosphere, such nanoparticles are usually oxidized to lead oxide nanoparticles. The widespread occurrence of such contamination of work premises and territories adjacent to industrial enterprises, as well as their generally recognized toxicity, determine the importance of experimental study of the toxicity of lead nanoparticles. The aim of the study was to experimentally investigate the toxicity of lead oxide nanoparticles on rats under subacute inhalation exposure conditions. Material and methods. Lead nanoparticles were generated by electric sparking from a pure lead rod. Their flow was mixed with air for oxidation to lead oxide and fed to the “nose only” inhalation exposure chamber. Female rats of the experimental group were exposed to lead nanoxide at a concentration of 0.215 mg/m3 for 4 hours, 5 times a week, for 3 weeks. The second group was a control group and breathed clean unfiltered air. After the experiment was completed, the rats’ body condition parameters were determined: hematological and biochemical parameters of blood and urine, as well as behavioral tests: the elevated plus maze test, open field test, and Barnes maze, and the summation threshold index was estimated. Differences between samples were assessed using the Student’s t-test. The differences were considered significant at p<0.05. Results. Subacute inhalation exposure to lead oxide nanoparticles aerosol led to the development of inflammatory reaction in rats, which manifested itself in the form of leukocytosis. At the same time, no changes in porphyrin metabolism and behavioral reactions were recorded in them. Limitations. The study was limited to investigate the indices of general toxic effects in an experimental study on subacute exposure of female rats to lead oxide nanoparticles using only one dose. Conclusion. Our findings emphasize the necessity of a comprehensive assessment of nanoparticles, especially those of industrial importance.