Investigation of polycyclic aromatic hydrocarbons and organochlorine pesticides in dry deposition and fractional rain samples

In this study, the amounts of polycyclicaromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) were determined in fractionally collected rain samples. Fractional wet deposition samples were collected in Abant Izzet Baysal University Campus which is a semi-urban area in Bolu, between April 2010 and January 2011. Samples were collected fractionally during a rain event and extracted with solid phase extraction method. HPLC-DAD and GC-ECD were used for the determination of PAHs and OCPs, respectively. The most abundant PAHs were 2-4 ringed ones. Naphthalene had the highest average deposition flux (2998 ng m-2) and the highest volume weighted mean concentration (2.35 ng mL-1) while chrysene had the highest arithmetic mean concentration (5.07 ng mL-1). The lowest average flux (10.7 ng m-2) and the lowest average concentration (0.009 ng mL-1) belonged to benzo[a]pyrene while benzo[k]fluoranthene had the lowest volume weighted mean concentration (0.006 ng mL-1). Although the applications of DDT have been prohibited, degradation products of it were observed in many samples. Moreover, the fluxes of some prohibited organochlorine compounds are found to be very high during agricultural application months. In dry deposition, it is found that the half of PAHs, except acenaphthylene, fluorine, phenanthrene and chrysene, showed normal distribution and those probably came from long distance to sampling area. In this study, Diagnostic Ratio and Back Trajectory analysis were used to determine pollution sources, and it is seen that vehicle emissions coming from TEM and D-100 highways and city atmosphere contributed to pollution sources.