Coal workers' pneumoconiosis, its causes and cure, is the subject of intensive studies by different laboratories throughout the world. This form of pneumoconiosis is believed to be caused by the inhalation and retention of respirable coal mine dust. Whether specific chemical compounds or synergistic effects of several compounds exacerbate the effects of the disease is not presently known. It is clear that before these questions may be answered a complete chemical analysis of coal dust must be made. This may then be compared with chemical analysis of coal dust found in the lungs of deceased coal workers. Discrepancies between these results may then indicate suspect chemical compounds. As part of an investigation to fully analyze respirable coal dust, trace elemental analysis by a novel wet-digestion procedure was developed.