Studies on commuters' exposure to BTEX in passenger cars in Kolkata, India.

Commuters' exposure to volatile organic compounds (VOCs) especially BTEX travelling in passenger cars in Kolkata, India were quantified in Phase I (2001-2002) and Phase II (2003-2004). Monitoring was made inside and in the immediate outside of passenger cars fitted with and without catalytic converters using different types of fuels, along two congested urban routes. During Phase I of the study, the benzene content in gasoline was 5% and the mean concentration of in-vehicle benzene in cars without catalytic converter was found to be as high as 721.2 microg/m3. In Phase II when the benzene content was reduced to <3% and with modified engine type, the mean in-vehicle benzene concentration was reduced to 112.4 microg/m3. The in-vehicle concentration varied with engine type and age of the vehicle. Roadside ambient mean concentration of benzene was 214.8 microg/m3 and 30.8 microg/m3 in Phase I and Phase II respectively.