PCBs and PBDEs in environmental samples from King George Island and Ardley Island, Antarctica

Abstract

The levels and distribution of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were investigated in various environmental matrices including soil, sediment, lichen (Usnea aurantiaco-atra) and moss (Sanionia uncinata) from Fildes Peninsula at King George Island and Ardley Island, west Antarctica. In general, PCBs and PBDEs were detected at very low levels in the samples collected during December 2009 to February 2010. The mean concentrations of total PCBs were 410 pg g⁻¹ dry weight (dw) (range 60.1–1436 pg g⁻¹ dw) in soil and sediment, 544 pg g⁻¹ dw (404–745 pg g⁻¹ dw) in lichen and 670 pg g⁻¹ dw (406–952 pg g⁻¹ dw) in moss. The lower chlorinated CBs dominated in all the samples except for the dropping-amended soils from Ardley Island, where hexachlorinated congeners were more abundant. Notably, CB-11 was detected at significant levels, accounting for about 20% of total PCBs in most samples, this higher ratio compared to that in the technical mixture might suggest unidentified sources. Average levels of PBDEs were 24.0 pg g⁻¹ dw (2.76–51.4 pg g⁻¹ dw) in soil and sediment, 14.2 pg g⁻¹ dw (7.51–22.3 pg g⁻¹ dw) in lichen and 15.8 pg g⁻¹ dw (6.54–36.7 pg g⁻¹ dw) in moss. BDE-47 dominated the detected congeners, whereas BDE-99 and 71 were more abundant in the dropping-amended soils from Ardley Island. These results indicated that long-range atmospheric transport could be the main pathway of POPs to King George Island although anthropogenic influence (e.g., from research station, tourism and biotic activities) could also influence the spatial distribution of POPs.