Road site soil samples were collected during premonsoon and postmonsoon season for two consecutive years of 2010-11 and 2011-12 and PAHs were determined. Various sites were selected for investigation to represent the industrial and high traffic activity areas of greater Guwahati, Assam, India. The road dust samples were collected from 32 sites over greater Guwahati. Eight common environmental PAH [Phenanthrene-(PHE), Benzo(K) Fluoranthene-(BKF), Benz(a) Pyrene-(BAP), Benzo(ghi)Pyrene-(BGHIP), Benzo(a) Anthracene/Chrysene- (BAA/CHR), Fluoranthene-(FLT), Pyrene-(PYR), Anthracene-(ANT)] were found to be distributed and their concentrartion were determined by using HPLC technique. The present data indicates that the total average of PAHs over the investigated sites was ranged from 1.58 ng/g to 13.17 ng/g. On individual scale, the highest concentration were 13.17 ng/g and 9.80 ng/g for BKF and PYR , meanwhile the lowest was BAA/CHR with value 2.29 ng/g in the industrial area. The investigation showed that the carcinogenic content of PAHs ranged from 40.05% to 40.89%. Polycyclic aromatic hydrocarbons (PAHs) are potentially mutagenic and carcinogenic substances occurring at various concentrations in atmosphere, soils, waters and sediments. PAHs, inherited both from natural and anthropogenic processes, are persistent organic pollutants (POP) due to their chemical stability and biodegradation resistance. The increase of road transportation, and of industrial and activities has led to a notable build up of PAH amounts in the environmental media.
