PARTICULATE POLYCYCLIC AROMATIC HYDROCARBONS IN URBAN AIR OF TEHRAN

Polycyclic aromatic hydrocarbons are ubiquitous in the urban atmosphere and one of the mostatmospheric pollutants to be identified as suspected carcinogens .the objective of this study was tocompare particulate pah profiles from several sites across tehran. atmospheric concentrations ofpolycyclic aromatic hydrocarbons in tehran were evaluated to study particulate pah profiles indifferent sites. the particles size distributions were unimodal with a fine mode diameter (pm<0.49 ىm).five sites were selected in residential areas and one site in rural area for representing various situationsand role of motor vehicles in producing polycyclic aromatic hydrocarbons. organics on the filter wereextracted with acetonitrile and a group of 16 polycyclic aromatic hydrocarbons was selected forevaluation. pah identification was done by high performance liquid chromatography. total pahconcentration associated with particles collected on the six-stage cascade impactor stages and after-filterin different sites ranged between 0.132 to 234.3 ng/m3. the mean concentrations of polycyclic aromatichydrocarbons, collected on each stage were: 4.17 ng/m3 for pm10-7.2 ىm, 5.69 ng/m3 for pm7.2 - 3 ىm,11.95 ng/m3 for pm3 - 1.5 ىm, 9.18 ng/m3 for pm1.5-0.95 ىm, 2.82 ng/m3 for pm0.95-0.49 ىm and 47.91 ng/m3for pm < 0.49 ىm respectively.