SEASONAL VARIATION OF VOLATILE POLY AROMATIC HYDROCARBONS FROM DIFFERENT SOURCES

Abstract

Understanding the seasonal variations of polycyclic aromatic hydrocarbons (PAHs) concentrations in ambient air in urban/rural or industrial regions is important to the effective control of air pollution in these regions. Based on an approximately a year round dataset, an intensive sampling program was conducted in this study, where a series of air samples was collected during this period at the four different function sites in South Al-Tabbin city. A total of 48 atmospheric samples were collected by high volume active air sampler. The gaseous and particulate phases of PAHs were extracted and analyzed using GC/MS together. The total air concentrations of 16 USEPA PAHs in the study area ranged from 76.48 ± 19.44 µg/m3 to 26995.86 ± 2835.91 µg/m3, with an average concentration of 7085.08 ± 773.98 µg/m3. Seasonal trends of PAH concentrations were observed with high concentration in winter and low in summer where the average concentration of PAHs in winter were ~1.6 times higher than that in summer. The diagnostic ratio analysis was employed to determine the primary PAH sources at different function sites. The analysis indicated that different sources influence the concentration of PAHs in the function sites where coal, oil combustions, vehicle emission, and industrial processes are the main sources. Particularly, the traffic vehicle exhaust was the largest contributor for RA. Meanwhile, PAHs were predominantly from coal and oil combustions for the industrial areas (CK, TIMS and AAS). According to BaP equivalent concentration, the potential health risks of PAHs at the two industrial sites are ~ 7.6 and ~ 4.3 times, respectively, those for residential area.