PCB in the air during landfilling of a contaminated lake sediment

We studied PCB concentration in the air during the build-up of a landfill of PCB-contaminated sediment. A small lake was remediated and the sediment (150 000 m3 containing about 400 kg PCB) deposited in a nearby landfill. PCB concentration in the air was elevated during landfilling and the extent was determined by the amount of sediment handled and the temperature. The air was enriched in more volatile PCB congeners compared to the deposited sediment, suggesting volatilization as the major transport process in addition to particle transport. The PCB concentration in air showed an exponential decline with distance from the centre of the landfill, with a one order of magnitude decrease 350 m from the centre. At a distance of 850 m from the centre about 5% of the elevated PCB level remained, which was significantly higher when compared to the reference concentration (15 km from the landfill). The PCB congener pattern changed gradually from the landfill centre to the reference. After the landfill was closed and the contaminated, dewatered sediment covered by uncontaminated soil, PCB levels and pattern were similar to that of the reference.