PCBs and chlorinated hydrocarbon pesticides in Antarctic atmosphere and hydrosphere

PCBs and chlorinated hydrocarbon pesticides such as DDTs and HCHs (BHCs) were measured in air, water, ice and snow samples collected around the Japanese research stations in Antarctica and adjacent oceans during December 1980 to March 1982. The atmospheric concentrations of chlorinated hydrocarbons decreased in the transport process from northern lands to Antarctica, but the compositions of PCBs, DDT compounds and HCH isomers were relatively uniform throughout this process. Regional and seasonal variations were found in aerial concentrations of these pollutants at Syowa Station and adjacent seas in Antarctica. Chlorinated hydrocarbons were also detected in snow, ice, lake water and sea water samples, in which rather high concentrations were found in snow and ice samples. This suggests that snow and ice serve as media of supply of these pollutants into Antarctic marine environment. Most interestingly, the concentrations of DDTs and higher chlorinated biphenyls were much lower in sea water under fast ice than in that from outer margin of pack ice. This indicates that the active removal of these pollutants is occurred in the sea under fast ice, and that is strongly associated with high primary productivity. It is, therefore, presumed that the concentrations of PCBs and DDTs in marine organisms living under fast ice in Antarctica could be lower than those in other oceans.