Abstract
This investigation was aimed at establishing procedures for obtaining data relative to the physical and chemical characterization of respirable coal mine dust for utilization in epidemiological studies of incidence of coal workers’ pneumoconiosis in different United States mines. In this paper the dust sampling and analytical procedures are briefly described and results are presented for three samples of approximately 4 grams each collected in each of two United States coal mines representing two different coal seams. Analyses were performed to determine the extent of differences ijn dust properties between (1) samples collected in the same mine and (2) samples collected in each of the two mines.