Association between occupational risk factors and lung function among small-scale gold miners in Mongolia: a cross-sectional study.

OBJECTIVES: This study aimed to assess the association between occupational risk factors and lung function among gold miners in a northern Mongolian province. METHODS: A cross-sectional study was conducted among 143 gold miners in July 2024. Data were collected through structured interviews, physical examinations, chest X-rays, and spirometry. Occupational exposures included workplace type (administrative, factory, or underground), dust exposure level (low, moderate, high, based on work duration and underground working hours), and N95 mask use. Lung function outcomes were assessed using forced expiratory volume in 1 second (FEV1), evaluated both both as an absolute value (liters) and as impaired lung function, defined by FEV1 <80% of predicted. Multivariable logistic regression was used to examine associations with impaired lung function, and linear regression was applied to assess determinants of absolute FEV1, adjusting for age, sex, and smoking status. RESULTS: Among 143 workers, mean FEV1 was 3.39 L; and 23.8% had FEV1 <80% of predicted. No occupational exposure was significantly associated with impaired lung function (FEV1 <80%). However, underground work was significantly associated with reduced absolute FEV1 (β = -0.22 L; p=0.026). N95 mask use was not significantly associated with impaired lung function after adjustment. CONCLUSIONS: Early lung function decline was not captured by the standard threshold. Therefore, monitoring absolute FEV1 may offer a more sensitive measure of early pulmonary changes among miners. Regular health monitoring and enhanced protective measures are urgently needed to prevent occupational lung diseases in resource-limited mining settings, including Mongolia and other developing countries.