Transfer of chlorinated biphenyls to Antarctica

PREVIOUS determinations of synthetic organic compounds in antarctic snow1 and in tissues of species inhabiting the antarctic marine environment2–5 have shown the presence of DDT compounds in almost all samples examined, but the apparent absence of polychlorinated biphenyls (PCB). PCB, however, are ubiquitous marine pollutants north of the Antarctic Convergence2,5–8 and were detected in all eggs and tissues of seabirds examined from the subantarctic Auckland Islands, centred at 166°05′E, 50°40′S. These data have been used to support the hypothesis that the atmosphere is not the primary medium of transport of this class of pollutants to remote environments such as Antarctica1. In the present paper we report the detection of PCB in the eggs of resident penguin species, by removal of unknown compounds previously interfering in the analysis, and in antarctic snow, by application of in situ extraction in the field of large volumes of melted snow. Equivalent levels and ratios of these pollutants in species resident north and south of the Convergence indicate atmospheric, rather than oceanic, transport to Antarctica.