The Mineral Content of Bituminous Coal Miners' Lungs

Lung samples from 30 bituminous coal miners have been analyzed for coal and noncoal dust. The latter has also been analyzed for quartz, other crystalline substances, and metallic constituents. Initially, the sample is freeze-dried, and ground in a mullite ball mill, and suitable aliquots are then digested by the King and Gilchrist procedure. Following the destruction of the lung matrix, the total dust is determined gravimetrically. The loss obtained on igniting the total mineral residue at 380°C represents the weight of the coal fraction. The resulting noncoal residue is then aliquoted for the determination of quartz and for the identification of other crystalline substances by x-ray diffraction. The analysis for the metallic constituents is accomplished by emission spectrography. Particle size analysis of the noncoal fraction is conducted by an electron microscopic procedure.