CONCENTRATION AND ENVIRONMENTAL SIGNIFICANCE OF LEAD IN SURFACE SNOW OF ANTARCTIC ICE-SHEET .3.

Lead as an ultra-trace heavy metal becomes one of popular topics in gl aciochemistry of the Antarctic ice sheet, because of its wry low conce rtration (pg . g(-1)) and background and its sensitivity to the qualit y of the environment. The lead concentration of surface snow of the An tarctic ice sheet (corresponding to modern precipitation) applying LEA F technique by Chinese scholars has systematically been studied for th e first time in the world. The distribution principle of lead concentr ation of surface snow of the Antarctic ice sheet is ''low in the west and high in the east'' along the route of 1990 International Trans-Ant arctic Expedition (TTAE). The concentration of lead in East Antarctica is 2-3 fold higher than that in Larsen ice shelf and Antarctic Penins ula, which majorly results from the activity of pre-Soviet Antarctic E xpedition. The concentration of lead in Larsen ice shelf and Antarctic Peninsula on be regarded as the background value of modern precipitat ion of the Antarctic ice sheet in the end of 1980s.