Regional-temporal Trends and Risk Assessment of Polychlorinated Biphenyls (PCBs) in Olive Lands in Bursa, Turkey

In this study, it was aimed to determine the spatial and temporal variations of polychlorinated biphenyl (PCB) levels in olive lands (0-5 cm) and to identify dominant PCB homologous groups and cancer risk values. In this context, surface soil samples were taken from seven olive lands in Bursa-Turkey for 9 months. Sampling points were categorized as rural, semi-rural, residential, and industrial areas. Regional-temporal trends of 43 PCB compounds were reported. The total average ( n-ary sumation (43)) PCB concentrations ranged between 8.3 +/- 3.31 ng/g DM and 15.4 +/- 3.3 ng/g DM. The lowest n-ary sumation (43) PCB concentration was measured at the rural area (Mudanya Yorukali-MY) and the highest value was measured at Orhangazi Asilzade (OA), which is an industrial area. The dominant homologous group in all seasons was found to be 5-CBs (31%) followed by 4-CBs (16%) and 6-CBs (15%). Cancer risks were calculated and risk trend was determined as ingestion > dermal > inhalation. The values ranged between 5.26 x 10(-6) and 1.28x10(-5), 2.62 x 10(-5) and 1.08x10(-5), 1.68 x 10(-1) and 6.9 x 10(-12) for dermal, ingestion and inhalation, respectively. Also, the correlation between the levels of certain soil characteristics (dry matter, pH, and temperature) was also investigated. Statistical results showed that for PCB#89/101, PCB#135/144, PCB#126, PCB#156/171/202, PCB#172 PCB#170/190 it was determined that there was a significant relationship.