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Investigation of PCB pollution: method validation and case studies from Ankara

Akduman, Nazan
Polychlorinated biphenyls (PCBs) are persistent organic pollutants which were not produced in Turkey, however both national and international studies illustrate a measurable amount of PCB pollution in receiving environments, aquatic fauna and people. In this study, various information sources such as the national and international scientific literature, official records and reports are investigated to obtain information regarding PCB pollution in Turkey. Furthermore, various PCB pollution analysis techniques for soil/sediment samples are investigated and the selected methods are established in the laboratories of METU. Satisfactory recoveries are obtained for methods for the extraction of PCBs, clean-up of extract and gas chromatographic (GC/ECD) analysis of the sample. Finally, field studies are performed in two locations in Ankara. The first one is a preliminary pollution investigation study around Lake Eymir. Lake Eymir is suspected to be contaminated with PCBs due to a nearby transformer repair facility. The second, more detailed study is performed for a 25 km reach of Ankara Creek, passing through the Industrial Zone, Sincan Dumpsite and Ankara Central Wastewater Treatment Plant. Total- PCB concentrations are in the range of 0.2 and 777 ng/g with the median of 37.1 ng/g. Toxic Equivalent Concentrations (TEQ) are assessed for dioxin-like congeners and Aroclor 1016/1260 basis. A Chemical Mass Balance Model is used to identify and apportion the sources of PCBs for Ankara Creek samples. Typically highly chlorinated Clophen mixtures are identified in sediments as the pollution sources.