[An experimental study of the fibrogenic effect of different metamorphic coal dusts].

An experiment on rats in vivo with bituminous, anthracitic and brown coal dusts from eight coal mines showed that the fibrogenic degree in experimental rats was related to the free silica contents of the coal dust, which varied from 0.72% to 9.84% in our experiment. Calcium, chromium in coal dust can increase the fibrogenic effect, while aluminum seems to have an antifibrogenic effect. The metamorphic degree of coal has a lesser effect on fibrogenesis than free silica and other mineral elements in coal.