Coal Dust-Induced Systematic Hypoxia and Redox Imbalance among Coal Mine Workers

Continuous inhalation of coal dust among coal workers leads to a variety of disorders. The present study aims to evaluate the potential oxidative stress associated with coal dust generated from coal mining activities among exposed workers through the antioxidant enzyme system, including superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH). In this study cohort, intensive coal mine workers were assessed for antioxidant variations. Blood samples were collected from dust-exposed workers (engaged in different activities at coal mines; n = 311) and residents of the same city (nonexposed, control group; n = 50). The workers' exposure to coal dust was categorized based on working area (administrative group, surface workers, underground workers), working hours (up to 8 h and more than 8 h), and time of service. The results showed significantly altered activities of SOD, CAT, and GSH among the whole exposed group and its categories compared to the control group. A significant difference was also observed between high- and low-exposure groups. Statistical analysis revealed a negative correlation between antioxidant activity (catalase and SOD) and coal dust levels. Besides, coal exposure was associated with the time of service, smoking status, and dietary habits. The findings of this study reveal higher oxidative stress among highly exposed coal mine workers (underground workers > surface workers > administrative group > nonexposed group), and longer working hours have more pronounced adverse effects on workers' health.