Introduction. Currently recommended methods of treatment of pneumoconiosis in the Russian Federation are mainly symptomatic. While approaches aimed at eliminating the cause of the disease, such as removing dust particles from the lungs, are practically not used in domestic clinical practice. It is believed that dust particles from the lungs can be removed using bronchoalveolar lavage (BAL), including total. However, despite the widespread use of the latter abroad in the treatment of pneumoconiosis, the effectiveness of removing dust particles from the lungs with its help remains questionable. This is due to the fact that the data available in the literature on the mass of quartz dust extracted from the lungs of patients with silicosis by the BAL method do not take into account its initial content in the respiratory tract. Since it is necessary to standardize lung dusting in workers in order to conduct such an assessment, it is not possible to do this in the framework of clinical trials. In this regard, it seems reasonable to conduct experimental studies to study the effectiveness of BAL as a method of removing aerosol particles of predominantly fibrogenic action from the lungs.

The study aims to quantify the effectiveness of removing aerosol particles of predominantly fibrogenic action from the lungs by bronchoalveolar lavage.

Materials and methods. The authors performed studies on white male Wistar rats weighing 250-300 g. Pneumoconiosis was modeled using intratracheal (i/t) injection of a suspension (fractions 1–5 microns) of quartz dust at a dose of 50 mg in 1 ml of 0.9% NaCl solution. After that, the experts have randomized the animals by body weight into three groups (six individuals each). In Group 1, a single BAL with large (10ml) volumes of lavage solution was performed immediately after the quartz dust administration, after which the animals were euthanized. In Group 2, a single BAL with large volumes of 0.9% NaCl solution was performed on the 28th day after quartz dust instillation, after which the animals were sacrificed. In turn, in Group 3, three BAL with small (3.3 ml) volumes was performed on the 7th, 14th, and 28th days, after which the animals were euthanized. The lavage fluid (LF) isolated from the animal was collected by scientists in a test tube to determine the total amount of quartz dust. Regardless of the BAL method used, the total volume of lavage fluid was fixed at ~10 ml. The scientists determined the amount of quartz dust in the lavage fluid and lungs using the gravimetric method. They analyzed the composition of the lavage fluid using light microscopy.

Results. When studying the quartz dust content, it was found that in Group 1 it was the highest in comparison with other groups, both in the lungs and in the LF. At the same time, the sum of the quartz dust masses in the lungs and LF was equal to the mass of dust initially injected into the animal (50 mg). After the BAL, 84% of quartz dust remained in the lungs.

In turn, Group 2 had lower amounts of quartz dust in the lungs and LF compared to Group 1.

It was also noteworthy that the sum of the masses of quartz dust in the lungs and lavage fluid was significantly (p<0.05) lower than the mass injected intratracheal. After the BAL, 79% of quartz dust remained in the lungs.

In Group 3, the amount of quartz dust in the lungs and lavage fluid was the lowest, as well as the amount of mass, which was significantly (p<0.05) lower than in the other groups. In addition, in this group, the difference in the mass of quartz dust injected intratracheally and the amount of its content in the lungs and LF was the greatest. After the BAL, 75% of quartz dust remained in the lungs. Microscopic examination of LF samples showed that if the BAL was performed immediately after instillation, quartz dust particles were detected exclusively outside the cells, while at a later date they were detected exclusively inside the alveolar macrophages.

Conclusion. BAL is an effective way to remove quartz dust particles from the lungs not only immediately after it enters the respiratory tract, but also later in the development of pneumoconiosis. Moreover, if free quartz dust particles are removed from the LF in the early stages, then at a later date they are exclusively phagocytized by macrophages. BAL can stimulate the process of lung self-purification by moving macrophages into the airway sections lined with ciliated epithelium and stimulating mucociliary transport.

Ethics. The experimental study was conducted in compliance with the necessary regulations (Helsinki Declaration of 2013, GOST 33044-2014 "Principles of good laboratory practice"; Order of the Ministry of Health of the Russian Federation No. 188n dated 04/01/2016 "Rules of good laboratory practice"). The study protocol was approved by the Ethics Committee of the Izmerov Research Institute of Occupational Health (Minutes of meeting No. 1 dated 01/23/2025).

Contributions:Tonshin A.A. — research concept and design, conducting experiments, collecting and processing experimental data, preparing literature data, writing text;Makarov A.F. — conducting experiments, preparing literature data, writing text;Krikunov O.V. — conducting experiments, writing text;Muravskaya M.P. — conducting experiments, writing a text;Tkachuk Yu.V. — conducting experiments;|Nikolaev I.M. — conducting experiments, preparation of literature data;Bonitenko E.Yu. — concept and design of research, editing.

Funding. The study was carried out within the Framework of research and development No. FGFE-2025-0023 state assignment.

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

Received: 05.03.2026 / Accepted: 23.03.2026 / Published: 25.04.2026