Profile of PAHs in the diesel vehicle exhaust in Delhi.

A preliminary study to determine the profile of PAHs in the exhaust of diesel vehicles plying on Delhi roads was conducted. Two different types of diesel vehicles (buses and trucks) with different age groups were selected for sampling purpose. The concentration of Total PAHs (sigma12 PAHs) was found to be 50.76 +/- 6.62 and 57.72 +/- 4.15 mg/g in the exhaust of buses and trucks, respectively. The levels of PAHs were found to be high in trucks as compared to that of buses. The total PAHs concentration in the present study was found to be higher as compared to other studies. Such a high concentration could be attributed to different parameters like the age of the vehicles, driving conditions, the fuel quality and the emission standards.