三峡库区土壤重金属背景值研究

在大规模、系统采样的基础上，通过不同均值计算方法的比较，提出了三峡库区土壤重金属含量背景值：As为5．835mg·kg^-1，Cd为0．134mg·kg^-1，Cr为78．03mg·kg^-1，Cu为25．00mg·kg^-1，Hg为0．046mg·kg^-1，Ni为29．47mg·kg^-1，Pb为23．88mg·kg^-2，Zn为69．88mg·kg^-1。与全国土壤背景值比较，三峡库区As、Hg背景含量低于全国背景值，Pb、Zn含量略低于全国背景值，Cd、Cr含量高于全国土壤背景值，Cu、Ni含量略高于全国背景值。根据本研究成果进行三峡库区环境质量评价，将能更加真实地反映三峡库区的实际情况，有利于库区土壤环境质量管理。

Background value of soil heavy metal in the Three Gorges Reservoir District

The background values of soil heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) were investigated based on extensive investigation in the Three Gorges Reservoir District (TGRD). After analyzing the samples under strict quality control and assurance procedures, the heavy metal concentrations in the soils were calculated using simple statistical method. The background soil values of the heavy metals in TGRD are 5.835 mg·kg^-1 for As, 0.134 mg·kg^-1 for Cd, 78.03 mg·kg^-1 for Cr, 25.00 mg·kg^-1 for Cu, 0.046 mg·kg^-1 for Hg, 29.47 mg·kg^-1 for Ni, 23.88 mg·kg^-1 for Pb and 69.88 mg·kg^-1 for Zn. Compared with the recommended background value by China National Environmental Monitoring Center (CNEMC) in 1990, As and Hg are low, Pb and Zn slightly lower, while Cd and Cr are high and Cu and Ni slightly higher than CNEMC standards. Based on the research, actual conditions are only realistically reflected by continuous field environmental quality appraisal in TGRD, which favors soil environmental quality management.