Impacts of coal mining on heavy metal concentration and microbial community composition in surrounding soils

Coal mining activities have been demonstrated to result in substantial environmental contamination, posing severe risks to surrounding soil ecosystems. However, the interaction between microbial community structure and environmental factors in coal mining areas remains poorly understood. In this study, we evaluated the health status of soils and the effects of heavy metals on microbial community structure in coal mining areas through comprehensive soil health assessments and sequencing. Our findings revealed that soils impacted by mining activities exhibited low soil health index values, with health grades ranging from moderate to poor. Active biomarkers including Gemmatimonadota (phylum), Patescibacteria (phylum), and Saccharimonadia were highly enriched in mine soils, with some developing metal tolerance. Additionally, potential pathogenic bacteria, including MND1, Bacillus, and Pannonibacter, and potential pathogenic fungi including Fusarium and Alternaria, showed significantly higher abundance in these soils. Heavy metal concentrations, particularly Cu and As, were strongly correlated with the distribution of certain bacterial genera, alongside variations in soil physicochemical properties, including C/N ratios and organic matter content. These findings demonstrate complex relationships among heavy metal pollution, soil properties, and microbial communities, underlining the potential risks posed by mining activities to soil health and agricultural productivity in affected regions.