Public Health Burden of Transport in Delhi

Abstract

Background Motorised transport contributes to health burden resulting from inactive lifestyles, air pollution (AP), and road traffic injuries (RTI). The burden is the greatest in rapidly motorising, low- and middle-income countries such as India. Cities in India are generally more polluted, travel is conducted through a diverse range of travel modes, and number of motor vehicles is growing rapidly in the absence of sufficient infrastructure for walking and cycling. The magnitude of health burden due to the three risk factors (AP, RTI and physical activity (PA)) and their determinants have not been quantified in India at a city level. Methods We present a case study of Delhi. We estimated travel patterns from household travel survey, developed emission forecast model for transport and modelled fine particulate AP, measured on-road exposure to pollution, and analysed RTI database. We used comparative risk assessment approach to estimate the baseline health burden attributed to the three risk factors. Results Pollution exposure and injury risk during active travel are an order of magnitude higher than in high-income settings. We estimated that 9% of all-cause mortality for population older than 15 years is attributed to transport-related AP or RTI. Up to 13% of baseline death burden has been prevented due to current levels of travel-related PA. In the presence of multitude of pollution sources, the share of passenger travel (motorised two-wheelers, cars, buses and auto rickshaws) to overall pollution remains modest (10%).There are significant sex-specific differences in health burden. These result from lower share of females in overall travel and higher baseline health burden among males. Exposure estimates also indicate significant socio-economic inequalities. Conclusions High levels of air pollution exposure and injury risk during active travel compared to cars need to be reduced to retain the current mode shares. Continuing absence of physical activity from public discourse on transport in India needs to be addressed. AP mitigation policies with a focus only on passenger transport will be insufficient to have any significant impact. Sustained reduction in the current levels of AP can only be achieved through a multi-sector strategy.