Abstract
BACKGROUND: Air pollution is a significant contributor to respiratory illness globally, and in India, evidence is scarce on whether smoking exacerbates this problem. OBJECTIVE AND METHODS: We aimed at assessing if being a smoker among public transit drivers increased risk for respiratory illnesses and affected performance of pulmonary function tests in a cross-sectional study in a metropolitan city of Gujarat, western state of India. We conducted a cross-sectional study among public transit drivers (those who were smoking and not smoking). Administration staff who were not smoking were considered as control group. We collected socio-demographic and medical history including occupational history (N = 296). We collected details of respiratory symptoms with standard tools and assessed pulmonary function tests (PFT) using spirometry. Group differences and regression analyses were conducted in R software. RESULTS: We found that respiratory symptoms among public transit drivers who smoked were higher than those who did not smoke and healthy controls. In PFT diagnosis, drivers who smoke displayed two times higher prevalence of obstructive pattern compared to drivers who did not smoke. There was a significant reduction in the larger as well as the smaller airway functions, reflected in reduction of FEV(1)/FVC ratio (p < 0.001) and FEF(25-75%) (p < 0.001), respectively, among drivers who smoked compared to controls. Our results indicate that being a driver with a smoking history leads to a 3.1% greater decrease in the FEV(1)/FVC ratio and about half a litre reduction in FEF(25-75%) compared to the drivers who did not smoke. CONCLUSION: We suggest there is a high need for smoking cessation programmes for public transit drivers as they are at higher risk for respiratory illnesses and reduced pulmonary functions when smoking is added to the existing vehicular exposure.