青藏铁路沿线土壤重金属的分布规律初探

Heavy metal distribution along the Tibet railroad

通过对青藏铁路沿线已经运营路段和正在修建路段两侧采集的土壤样品进行重金属含量测定分析,研究修建青藏铁路对铁路沿线土壤生态环境的影响。分析的重金属元素包括Hg和Pb。其中Hg采用氢化发生等离子发射光谱法,Pb采用等离子发射光谱法进行测定。测定结果表明,已运营铁路沿线重金属铅和汞具有显著的规律性变化。在铁路一侧,铅和汞含量随距离变化呈现正态分布,其最高峰值出现在距铁路50m左右。而且,铅和汞含量高于土壤背景值以及正在修建铁路两侧的土壤含量。通过对土壤理化性质的分析表明,已运营铁路段土壤的理化性质与铅和汞含量变化没有显著的相关性,因此,可以推断,铁路运输已经造成了铁路两侧土壤一定程度的重金属污染。

It is well known that the ecological environment in the Tibet Plateau is fragile and it can be disturbed readily by human’s activities. In order to study the impact of railroad construction on soil environment in Tibet Plateau, heavy metal content and its distribution along the Tibet railroad was investigated. The metal elements including Hg and Pb were determined by the plasma radiation spectrum. The results showed that there was an obvious normal distribution of Pb and Hg and the maximum appeared in the 50 m beside the railroad. The content of Pb and Hg were higher than that of soil background value. The Pb and Hg distribution along the being constructed railroad reach had not the similar situation. The related analysis suggested that the physical and chemical properties didn’t make a remarkable influence on the Pb and Hg distribution, it is thus concluded that the railroad transportation is likely to cause heavy metal pollution in soil to a certain extent.