[Pathological survey of lung cancer induced by tin mine dust in Yunnan]

Pathological changes of lung cancer in miners of Yunnan Tin Mine were studied, and additionally, mineral dust in the miners' lung were also investigated by using scanning electronic microscope, energy disperse X-ray spectrometer and electronic probe. The results showed: 1. mineral dust caused active hyperplasia, atypical hyperplasia, metaplasia and atypical metaplasia of the epithelial of alveoli and bronchi, which was able to induce cancer. 2. Pneumoconiosis-like changes in the miner's lung are correlated with the high incidence of lung cancer. 3. Correlated also with copper, lead, zinc and iron may be the high incidence of lung cancer. 4. Transition form from hyperplasia and atypical hyperplasia of alveolar epithelia to malignancy was observed. It suggests that lung squamous cell carcinoma probably originates from the alveolar epithelia of the lung.