Pulmonary injury in laboratory animals induced by Huai-Nan coal mine respirable dust

The BAL technique was used to assess the pulmonary injury of coal dust and rock dust in Huai-Nan coal mine in Anhui Province. Dust suspended in saline and dust-free supernatant were instilled intratracheally to Wistar rats and Syrian hamsters. Saline was used in treating controls. The animals were sacrificed 24 h after treatment, their lungs were lavaged, and pulmonary damage was evaluated by cellular and biochemical assays of lavage fluid. Pulmonary injury was expressed by the cell toxicity index (CTI). CTI is the product of the number of times of meaningful parameters for treated groups compared to controls (LDH, acid phosphatase, and polymorphonuclear neutrophils in this case). The CTI values were found to be 5.19, 2.28, and 5.15 for rock dust, coal dust, and Shanghai suspended particulates, respectively. The toxicity of rock dust is higher than that of coal dust, but is similar to that of Shanghai suspended particulates. The cell toxicity of dust suspension solution is higher than that of dust-free supernatant. CTI can be used as an indicator of the relative toxicity of respirable dusts in in vivo studies.