Features of the development of the mucosal immune system of the upper respiratory tract in ferrous metallurgy workers

Introduction. The exposure to industrial aerosols triggers the response of the adaptive and innate mucosal immunity in the upper airways.

Objective. To analyze the impact of work-related risk factors on the development of local mucosal immunity in workers engaged in extraction of vanadium-bearing iron ore, and cast iron and steel production.

Materials and methods. We examined one thousand five hundred forty seven male workers of two mining and metallurgical industries. The first cohort included 788 vanadium-bearing iron ore miners and the second cohort comprised 719 cast iron and steel production workers, both standardized by age and years of employment. Occupational risk factors identified in both cohorts included the exposure to fibrous aerosols and aliphatic hydrocarbons, and poor microclimate (high or low air temperature) at workplaces. The workers of the second cohort were also exposed to manganese compounds, vanadium (V) oxide, chromium, nickel, and iron compounds. The control group consisted of 40 engineering and technical personnel.

Results. A significant increase in secretory immunoglobulin A (sIgA) was detected in the miners exposed to aliphatic hydrocarbons and low air temperature. In the ferrous metallurgy workers, the exposure to low air temperature, crystalline silicon, and aliphatic hydrocarbons caused a significant decrease in the level of sIgA while the exposure to manganese oxides induced a decrease in the bactericidal function of neutrophils.

Limitations. The main limitations of the research were related to the selected criterion of inclusion in the merged occupational cohorts with account for exposure to adverse microclimate parameters, silicon-containing aerosols, aliphatic hydrocarbons, and manganese compounds. In view of the multiplicity of occupational risk factors in the industry, it is important to conduct additional studies of a larger sample for qualitative and quantitative presentation of convincing evidence of health effects of other factors of the work environment.

Conclusions. We established a multidirectional response of the mucosal immunity to production factors in the examined workers. A combined exposure to chemical and physical occupational factors has a stronger health effect than a single one. Differences in the level of sIgA in workers exposed to different occupational hazards prove the advisability of an in-depth immunological examination combined with an assessment of the functional status as indicators of occupational adaptation.

Compliance with ethical standards. The study approval was provided by the Local Ethics Committee of the Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers (Minutes No. 8 of December 26, 2016). 

Patient consent. Each participant of the study (or his/her legal representative) gave informed voluntary written consent to participate in the study and publish personal medical information in an impersonal form in the journal "Gigiena i Sanitariya (Hygiene and Sanitation, Russian journal)".

Contribution:
Bushueva T.V. — the concept and design of the study, the collection and processing of the material, statistical analysis, writing text;
Roslaya N.A. — the concept and design of the study, writing text;
Varaksin A.N., Shastin A.S., Karpova E.P., Gribova Yu.V., Sakhautdinova R.R., Vedernikova M.S., Labzova A.K. — the collection and processing of the material, statistical analysis;
Gagarina M.S. — editing.
All co-authors — approval of the final version of the article, responsibility for the integrity of all parts of the article.

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

Acknowledgement. The study had no sponsorship. 

Received: October 27, 2022 / Accepted: December 8, 2022 / Published: January 12, 2023