Respiratory symptoms and lung function impairment in underground gold miners in Ghana

Abstract

Background: This is the first study in Ghana in the Obuasi gold mines where the silica content of the respirable dust is 10%, less than in previously studied gold mines, with only 23% of the miners
having ever smoked. Objectives: The study was to assess the prevalence of respiratory impairment in the Ghanaian gold miner and to quantify the effects of the respirable dust on pulmonary function
Design: A cross sectional epidemiological study Method: The study was carried out using MRC respiratory symptoms questionnaire, spirometry, and personal respirable dust measurements.
Results: A total of 1236 miners were studied. The mean age was 39.7 ±5.8 (SD) years with a mean of 12.6 ± 6.7 (SD) years underground service and a mean total cumulative exposure to dust of 10.34
±5.61 (SD) mg.m-3.years. The prevalence of chronic bronchitis was 21.2% and not clearly related to cumulative exposure. MRC breathlessness grade≥2 was 31.3%, significantly related to cumulative
respirable dust exposure after adjustment of age and smoking. There was however significant reduction in FEF25-75% with increasing dust exposure and an interaction with ever smoking. There was no correlation between cumulative exposure to respirable dust and FEV1 % predicted in any group, suggesting that exposure to respirable silica
at a mean level of 0.06 mg/m3 had no deleterious effect on FEV1 in a population with little tuberculosis, good housing and a low level of cigarette smoking. Conclusion: The prevalence of chronic bronchitis
in the Ghanaian gold mine is related more to smoking than any occupational factors