Shared mineral pathology in malignant and non-malignant lung tissues of non-smoking women from Xuan Wei, China

Household coal smoke was evidenced to cause the uniquely high lung cancer mortalities in Xuan Wei, China. Lung cancer screening in local villagers found concurrently high prevalence of interstitial pneumonia. What could be the shared hazard linking those pathologies? Could it be some coal-derived mineral deposit in lungs that causes both fibrotic and malignant changes? A case-control study was conducted by recruiting 50 lung cancer cases and 30 pseudotumor controls among non-smoking women from Xuan Wei, China. The severity of interstitial lung abnormalities (ILAs) was compared between cases and controls by high-resolution computed tomography (HRCT) and histopathological analysis; mineral deposits in lung tissues were examined by light microscopy and electron microscopy techniques. The lung cancer case group and the pseudotumor group share this characteristic of abundant ILAs while the fibrotic changes are more severe in lung cancer than pseudotumor cases. Fibrotic changes are more severe in peribronchial lymph nodes than in lung parenchyma. Mineral deposits embedded in the anthracotic pigments are visible under polarized light microscopy (PLM) due to their birefringence. The morphology of this birefringent mineral resembles that of acicular berthierine-chamosite identified in Late Permian coal from Xuan Wei, China. These preliminary findings underscore the need for further investigation into the mineralogical factors contributing to the high incidence of lung cancer in this region.