DDT is a useful model compound for studying the circulation of a toxic pollutant in the global environment1,2. An understanding of this process could in future be related to potentially more hazardous materials. Present models of the dynamics of DDT circulation can account for only a small fraction of the amounts of DDT and DDE which are known to have been released into the environment. Major unknowns include the extent to which the atmosphere and oceans act as reservoirs and the transfer rate of these residues from the atmosphere to the oceans where, according to present ideas, they may be removed from circulation by transfer to the abyss3. Such atmospheric and oceanic transport mechanisms may carry pollutants into the ecologically protected area of Antarctica and it is necessary to assess the extent to which this is occurring and the relative importance of alternative input routes. The atmosphere has been assumed to play the major role in the transport cycle but there is a lack of supporting data. We report here levels of DDT and metabolites in Antarctic snow which suggest that the role of the atmosphere in the transport of DDT may have been overemphasised.
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