[Study on the pathogenic factors of pneumoconiosis in Beijing coal district].

Ferruginous bodies were first found in the lung tissues of coal miner autopsies in Beijing Coal mining. District irrespective of the presence or not pneumoconiosis, ferruginous bodies were found in the lung tissues as examined with two methods, tissue section and digestion and there was significance difference in their number. Two kinds of ferruginous bodies, one a "coal body", the other an "amphibole body" were distinguished when examined by EDXA. The fibrous particles in the dust extracted from the lung tissue are the physical basis of ferruginous bodies formation. After the lung dust has been subjected to X-ray diffraction analysis, there are also amphibole bodies in the lung tissue. There is no doubt that the presence of asbestos in the coal mine is one of the pathogenic factors of pneumoconiosis.