Measurements of polycyclic aromatic hydrocarbons in an urban atmosphere of Agra, India

sixteen polycyclic aromatic hydrocarbons (pah) were measured in total suspended particulate matter (tspm) samples collected at an urban and industrial cum residential site in agra (india) from december 2005 to december 2006. the average total pah concentration was found to be 115 ± 17 ng m-3. the measured concentrations were found to be lower than those reported from other cities in india like chennai, delhi, kanpur, mumbai and kolkata. the mass distribution in air was dominated by high molecular weight compounds. pah concentration showed a significant seasonal cycle during the year with greater concentration during the cold months due to changes in emission sources and meteorological factors. the presence of specific tracers and calculation of characteristic molecular diagnostic ratios revealed vehicular exhausts and emissions from coal and biofuel combustion as the major sources of these compounds.