Prevalence of Respiratory Symptoms, Lung Function Abnormalities and Cardiac Conditions in Jeepney Drivers Exposed to Different Levels of Black Carbon

Abstract

Background & Aim:  The jeepney, a traditional mode of transportation in the Philippines since the end of World War II, has been shown by a recent study to be a major source of black carbon (BC) in the air of Metro-Manila. Chronic exposure to black carbon may constitute a significant health hazard for jeepney drivers.  This study assessed the adverse effects of BC exposure to on the prevalence of symptoms, electrocardiogram (ECG) and lung function abnormalities in jeepney drivers in selected areas in Metro-Manila. Methods:  Between December 2019 and March 2020, jeepney drivers plying two routes with different levels of measured BC were assessed on their current health status using a modified version of the BOLD questionnaire, ECG and spirometry.  The effect of BC severity and other respiratory risk factors such as smoking, environmental and other occupational exposures were also determined. Results:   One hundred three (103) jeepney drivers with a mean driving experience of 21.4 ± 11.3 years participated in the study, grouped according to severity of BC levels in the route.  Jeepney drivers on the route with higher BC severity reported five times more symptoms (p=0.005) and showed 3 times more ECG abnormalities (p=0.014) between the two BC groups using univariate analysis There was no substantial difference in lung function parameters were seen in the comparative BC groups. Logistic regression analysis showed that high BC levels accounted significantly for increased prevalence of symptoms (OR=5.84 [95% CI: 1.60, 21.39], p<0.01) and ECG abnormalities (OR=3.2 [95% CI: 1.22, 8.37], p=0.018) in the high BC group. No significant effect of other respiratory risk factors was found. Conclusion:  The study provides evidence of the effect of BC levels on the prevalence of symptoms and ECG abnormalities in a vulnerable and highly exposed population such as jeepney drivers. Further studies are required to determine the effect of BC exposure on lung function in this population.