Symptoms and Lung Function Values in Nigerian Men and Women Exposed to Dust Generated from Crushing of Granite Rocks in Calabar, Nigeria

This study was carried out to determine lung function and respiratory and non-respiratory symptoms among men and women exposed to dust emitted from crushing of granite rocks and to compare them with control men and women not exposed to any known air pollutant. The sites were the granite rock crushing industries in old Netim, Akamkpa Local Government Area of Cross River State, Nigeria. Respirable dust level was higher in the dust-emitting sites (1.087±0.243mg/m) than in the control areas (0.099±0.007 mg/m; p <0.001). The mean anthropometric parameters (age, body weight and height) between the two groups were not significantly different. However, all the values of lung function indices except FEV1% were significantly lower in the dust-exposed group than their control group. (p < 0.001 for FEV1, FVC and PEFR) thus, suggesting restrictive lung defect among the exposed workers. Lung function indices correlated negatively with duration of service of the granite industry workers. The incidence of the major respiratory symptoms viz: unproductive cough, chest pain, catarrh and dyspnoea among the test group were higher (p<0.05-0.001) than in control group. Among the presenting non-respiratory symptoms, headache and night sweat were more common in the dust-exposed group than the control subjects (p<0.001). Chronic exposure to dust generated from crushing of granite rocks impairs lung function and causes some respiratory and non-respiratory symptoms in men and women. Length of service was a predisposing risk factor.