Association between duration of coal dust exposure and respiratory impairment in coal miners of West Bengal, India.

Purpose. The prevalence and severity of respiratory disorders are very high among coal miners as continuous exposure of workers in such an environment leads to accumulation of dust in the lungs. This study was designed to assess the prevalence of lung function impairment and to determine whether there is any correlation between dust exposure duration and lung function indices. Materials. Two hundred and thirty underground coal dust-exposed workers and 130 age-matched non-exposed workers were recruited from an underground mine in West Bengal, India. A spirometry test was performed for lung function and also basic information on personnel's dust exposure, smoking and respiratory morbidity was collected. Student's t test, Pearson's correlation coefficient (r), uncorrected Pearson's χ2 test and Fischer's exact test were performed for statistical analysis. Results. Lung function indices were significantly (p < 0.050) impaired between the exposed (43.91%) and non-exposed (23.85%) groups. In addition, highly significant decrements in the pulmonary volumes of exposed subjects were also noted. Furthermore, a high negative correlation was observed between spirometric results and exposure time in the exposed group compared with the non-exposed group. Conclusion. This study suggested a positive relationship between exposure time and lung function deterioration.

Combined effect of coal dust exposure and smoking on the prevalence of respiratory impairment among coal miners of West Bengal, India.

Accelerating prevalence of coal workers pneumoconiosis is considered as a serious occupational health problem. This cross-sectional study was designed to determine the prevalence of lung function impairment of underground coal miners in West Bengal, India. A total of 230 underground coal dust-exposed subjects and 130 nonexposed subjects were examined for lung function test and also information on sociodemographic characteristics, addiction, respiratory morbidity, personnel protective equipment and dust exposure were collected. Lung function impairment was significantly higher in exposed group than nonexposed group and personnel dust exposure level were exceeded above the NIOSH recommended level. In addition, respiratory ailments were found to be higher in exposed group than the nonexposed group. So, this study has established the need for an advanced understanding of the quantifiable and measurable remedies for protection of lung disorder of coal mine workers.