| Summary: | The presence of PCBs was evaluated in environmental samples collected in Antarctica during the 1990-91 and 1991-92 Italian Expeditions by using an optimized procedure for GC-ECD peak assignment. In particular, marine sediment samples from Terra Nova Bay and Ross Sea, and lake sediment and soil samples from Victoria Land, near to the Italian Base (BTN) (1990-1991 expedition) were collected and analyzed. The relevant PCB concentrations ranged between 30-160, 60-120 and 40-70 pg/g respectively, and were strongly dependent on the particle size distribution of each sample as found in previous expeditions. The depth profiles of PCB content in marine sediment samples collected in a few stations clearly show that PCBs are confined in a surface layer of about 10 cm. A coastal sea water depth profile of PCBs before and after pack ice melting was also obtained by collecting samples in Terra Nova Bay-Gerlache Inlet (1990-91 expedition). The total PCB concentration was about 140 pg/l and was practically constant up to 25 m deep. At 250 m which is near the sea bed, an increase of PCB content up to about 200 pg/l was observed. Finally, PCBs were measured in sea water samples collected in the same area (1991-92 expeditions), showing an increase of about 70% in the surface water layer after pack ice melting.
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