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

Abstract

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.

Keywords:

• coal miners
• pulmonary function
• respiratory morbidity
• dust exposure
• work experience

Acknowledgements

The authors would like to thank the management of the colliery for allowing permission to perform the study and also thank the medical and safety officer for giving their valuable time. The employees are thanked for their cooperation throughout the project work. The authors would also like to thank the Department of Physiology, Serampore College for providing the instrument facility.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by PG Grant of Department of Physiology, Serampore College [Grant No. SC/Physiol/PG/2014/007].