The particles of pneumoconiosis minerals in dustpolluted air are below 5 microns in size of inorganic particulate matters. The pneumoconiosis mineral particles of about 0.5 micron in size seem to be particularly active in causing pneumoconiosis. The particles below 0.1 micron are too small to be retained in the lungs, and the particles below 5 micron in size can pass from the lungs to blood vessels and thence may reach the lymphatic system. Many important problems on pneumoconiosis are left unsolved yet. The study on the pneumoconiosis-mineralogical composition is therefore of vital importance in attempting to solve those problem. Investigations have been made in this line, and the results are summarized as follows:
1) The composition of pneumoconiosis minerals of below 5 micron is of kaolinite, montmorillonite, Biotite, plagioclase and quartz.
2) The compositition of the specimens below 2 micron is of kaolinite and montmorillonite.
3) The composition of the specimens below 0.5 micron is only of montmorillonite.
