Evaluating the health cost of transport pollution

Rapid urban growth and industrialization has degraded urban ecosystem. Out of several urban ecosystem components impact on ambient air quality is more perceptible. Amongst the several sources of urban air pollution the share of vehicular exhaust emission is rising, over time, in many Indian cities; this is due to increasing vehicular population. Carbon monoxide, oxides of nitrogen and particulate matter present in the exhaust of a vehicle cause major health impact on the urban population. High concentration of these pollutants in the ambient environment of the congested road stretches causes pulmonary diseases. To design any policy to mitigate urban transport pollution estimation of health costs is a prerequisite. In developing country like India very little comprehensive research has been conducted to estimate health cost of urban transportation. Literatures on health costs due to emission of pollutants from different modes of vehicles are largely dependent on studies conducted in United States. Absence of epidemiological studies, in India, on urban transport has compelled the researchers to transfer the benefits of such studies to Indian transport sector. Transport economists, in India, have used transfer of benefit method to estimate health cost based on US research studies. In such studies adjustments have been made on certain parameters like demography, income and currency purchase power between the two countries. However, appropriateness of such benefit transfer will remain important because of cultural dependence on methodology adopted on health cost estimate, which cannot be neutralized by such adjustments. In this paper, based on available data from different research publications the health costs arising out of transport pollution are estimated for different traffic flows in Kolkata. Emission rates of various pollutants from different vehicle modes are also collected to derive the aggregate pollution for a particular traffic flow. Survey reports on traffic flow in Kolkata is also used to ascertain the modal splits in a particular traffic flow Finally, the health cost estimated in this paper are used to examine how far shift in passenger's modal choice reduced the aggregate health cost in a congested road stretch. Under this context policy implications designed to shift passengers using personal vehicle to mass transport modes is also discussed.