Geochemical Characteristics and Health Risks of Coal Dust: An Integrated Review from Component-Dependent Toxicity to Emerging Oxidative Toxicity Indicators

Coal mining and consumption, a persistent source of global energy, pose significant occupational health risks. Through a bibliometric analysis of 562 publications (2001–2025), this review delineates the evolution from conventional metrics (mass concentration, free silica content) toward advanced characterization of mineralogical/geochemical heterogeneity and component dependent toxicity mechanisms. Evidence confirms that multiple toxic elements are enriched in the respirable fraction, with bioaccessibility critically governed by particle size, host phase, and chemical speciation. In vitro studies using simulated lungs and gastrointestinal fluids demonstrate that acidic environments significantly accelerate toxic metal dissolution, triggering oxidative stress. While the bioaccessibility of inorganic constituents has been extensively studied, that of complex organic pollutants, particularly polycyclic aromatic hydrocarbons, remains a critical knowledge gap. Oxidative stress is now recognized as a pivotal mechanism linking coal dust exposure to inflammation and genotoxic damage. Emerging abiotic toxicity indicators, such as environmentally persistent free radicals and oxidative potential, offer promising avenues for understanding and risk prediction; however, their analytical methodologies require further standardization and refinement. This review provides a scientific foundation for developing a next-generation risk assessment framework that integrates multi-dimensional coal dust characteristics, bioaccessibility, and oxidative potential, thereby guiding future research to better protect the health of coal miners.