EVIDENCE FOR SHORT-RANGE TRANSPORT OF POLYCHLORINATED-BIPHENYLS IN THE CANADIAN ARCTIC USING CONGENER SIGNATURES OF PCBS IN SOILS

The Distant Early Warning (DEW) Line, a series of radar stations spann ing the Canadian Arctic, is closing. In order to determine the environ mental status of these installations, the Canadian Department of Natio nal Defence has sponsored an assessment of soil contamination, the par tial results of which are presented here. A comparison of PCB concentr ations in background samples taken from pristine areas near the radar sites and samples taken in remote locations (> 20 km distant) provides evidence for short-range redistribution of PCBs. Principal component analysis, which was used to highlight differences in congener composit ion, provided confirmation of this observation. The PCB congener signa tures for background samples taken at the radar sites correlated well with PCB signatures from contaminated locations at the radar sites. In contrast, the congener signature attributable to atmospheric, or long -range transport, contained a relatively higher proportion of more vol atile congeners, which can be attributed to the increased atmospheric residence time.