东天山乌鲁木齐河源1号冰川雪冰中痕量元素揭示的大气污染信息

THE SEASONAL VARIATIONS AND SOURCES OF TRACE ELEMENTS IN HEAD WATER GLACIER NO.1 IN rümqi,EAST TIAN-SHAN

为认识东天山乌鲁木齐河源1号冰川地区大气中痕量元素的组成特征和污染信息,利用高分辨电感耦合等离子体质谱仪对2008年10月采自乌鲁木齐河源1号冰川雪坑中24个样品中可溶性痕量元素Al、Ba、Co、Cr、Cu、Li、Ni、Sb、Sr、U、V、Fe、Cd、Zn和Pb的浓度进行了测试和研究.结果表明,痕量元素的浓度最大值和最小值之比在27(Sb)到435(Li)之间,浓度最大值出现在夏季.除岩石和土壤粉尘外,人为污染是1号冰川中痕量元素的另一个重要来源.对于Pb和Cd,人为污染是主要来源.对比可知,乌鲁木齐河源1号冰川雪冰中痕量元素的浓度和沉降通量明显高于中亚其它地区冰川雪冰;更远远高于格陵兰和南极雪冰.研究揭示了该地区大气不仅受到较高粉尘的影响,也受到人为污染的影响.

In order to understand the composition and potential pollution of the trace elements in the atmosphere on eastern Tian-Shan,concentrations of 15 trace elements,e.g.Al,Ba,Co,Cr,Cu,Li,Ni,Sb,Sr,U,V,Fe,Cd,Zn and Pb were determined by high resolution inductively coupled plasma mass spectrometry（HR-ICP-MS）.Samples were from a 2.4 m snow-pit collected on 25 October,2008 from No.1 Glacier of head water in rümqi.Results indicate that there were large changes in the concentrations of these trace elements,from the lowest concentration of U（0.006 ng·g-1） to the highest concentration of Fe（20871 ng·g-1）.There were also large variations of Max/Min value,from 27（Sb） to 435（Li）.The concentrations also had larger annual fluctuation,with higher values in summer.Crustal enrichment factors（EFc） of trace elements indicate that besides rock and soil dusts,anthropogenic pollution is an important source of trace elements in the atmosphere of the studied site,and is the main source for both Pb and Cd.Comparison with other sites in central Asia shows higher concentrations of trace elements in the studied site,and much higher than Greenland and Antarctic.The deposition flux of trace elements are 10 to 70 times higher than eastern Rongbu glacier,about 100 to 1000 times higher than in Greenland,and about 700 to 20000 times higher than in Antarctica.The atmosphere in this area was affected not only by higher loading of dusts but also anthropogenic pollution.