Elemental composition of sputum, immune status, and features of pharyngeal microbiota in workers of the anode department of a copper smelter

The development of bronchial and pulmonary pathology depends on characteristics of the aerosols and individual resistance of the body, largely determined by the immune system, to their exposure. Mucous membranes of a healthy person are colonized by saprophytic bacteria or normal microbiota. Yet, changes in the composition and properties of the microbial landscape induced by adverse environmental factors increase the risk of inflammation and contribute to changes in the reactivity of the immune system.

The study aims to establish the immune status, microbiota of the pharyngeal mucosa, and the elemental composition of sputum, given its cellular composition, in workers of the anode department of a copper smelter.

We tested sputum culture and elemental composition, established clinical and immunological status, and analyzed pharyngeal microbiota in 28 workers of the anode department of a copper smelter. Based on the results of testing, the subjects were divided into two groups with (1) and without (2) leukocytosis (>10 cells in the field of view) detected in sputum.

We found no acute or chronic diseases of the bronchi and lungs in the examined workers. In group 1, we observed shifts in the immune response manifested by a decrease in the number of immunocompetent cells, activation of neutrophil phagocytosis, formation of reactive oxygen species in neutrophils, and displacement of normal microbiota of the oropharyngeal mucosa by opportunistic microorganisms (in 100% versus 35%, p<0.05). The elemental composition of sputum was noted for a higher frequency of iron and lead detection and increased concentrations of barium, lead, iron, arsenic, molybdenum, antimony, vanadium, and cadmium. We established a significant effect of metals contained in sputum on cellular, humoral, and local immunity.

The inflammatory bronchopulmonary response to toxic aerosol exposure is accompanied by changes in the cellular and phagocytic links of immunity, as well as in the microbial landscape on the mucous membrane of the upper respiratory tract characterized by displacement of normal biota by opportunistic microorganisms.

Limitations. This study has certain limitations associated with the small sample size and the lack of opportunity to compare metal concentrations found in sputum with reference levels.

Ethics. The study was approved by the Local Ethics Committee of the Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers (extract from the minutes of the meeting No. 8 dated 12/26/2016).

Contributions:
Karpova E.P. — study conception and design, draft manuscript preparation;
Bushueva T.V. — study conception and design, draft manuscript preparation;
Roslaya N.A. — study conception and design, draft manuscript preparation;
Shtin T.N. — physicochemical analysis of sputum;
Fedoruk A.A. — description of working conditions of the subjects;
Gurvich V.B. — study conception;
Labzova A.K. — clinical tests;
Gribova Yu.V. — clinical tests;
Gazimova V.G. — sample enumeration;
Khlystov I.A. — data analysis.

Funding. This research received no external funding.

Conflict of interest. The authors have no conflicts of interest to declare.

Received: 08.11.2024 / Accepted: 02.12.2024 / Published: 10.12.2024

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