[Comparative study on the retention effect of the inhaled mineral and coal dusts in rat lung]

The pulmonary retention and physico-chemical characteristics of the dust are very important factors in the occurrence of pneumoconiosis. This paper reports a comparative study on the retention characteristics between the inhaled mineral dust and coal dust in rat lung. The dust quantities in the lungs and the mediastinal lymphatic nodes were determined by the formic acid digestion method. The results showed that the pulmonary retention quantities of the coal dust in rats were higher than those of the mineral dust on the third day but lower on the 90th day after exposure for two weeks. The results suggest that the mineral dust can deposit in the lung longer than the coal dust, and the lymphatic system is important for the pulmonary elimination of the dust.