PCB Fingerprinting - A Useful Tool in Sediment Characterization and Source Localization

PCB is of environmental concern in Norway. Investigations and monitoring results have shown that more than 200 aquatic areas and land sites are PCB contaminated. From this results consumption bans has been given in 24 marine locations. PCB has never been industrial produced in Norway, but was imported from manufacturing countries since mid 1950. PCB was nationally banned in 1980. The source evaluations have been difficult due to diverse and diffuse input to the environment. Use of raw materials or PCB containing products has resulted in extensive accumulation in soils, sediments and biota. Risk-based approaches introduced in remediation during the 1990 initiated the apparent need for a working tool in PCB sources localization. Chemical concentration levels had so far been the tools for characterization and decision-making. Based on this a chemical fingerprint method was developed to distinguish different types of PCBs present, PCB manufactures and potential PCB containing products that had been used. The development was additionally triggered by the transition from total PCB quantification to congener specific analysis. Through an extensive literature study of internationally published analytical work of commercial PCB mixtures and product it was possible to define more than 20 standard PCB profiles. The standard profiles from different manufactures provide distinct fingerprint signals that can be recognized in soil and sediment samples. Unfortunate the method is so far not valid for higher tropic biotic levels, due to selective intake and accumulation. This paper explains the different steps in development of the standard PCB profiles and presents some guidance for the practical use in environmental studies. Selected case studies from the authors PCB database consisting more than 3000 data sets will be given.