陕西花椒主产区部分土壤中重金属的分布规律研究

在陕西17个花椒林地中采集土壤样,采用电耦合等离子质谱法等方法测定土壤样中重金属元素含量,并进行各元素之间的关联和线相关分析,确定陕西主要花椒栽培地土壤重金属的含量和安全性。结果表明,Pb、Hg、Cr、As、Cu含量均低于国标中的风险筛选值,仅来自凤县石铺村土壤样的Cd含量大于国标中的最大风险管控值,这可能与Cd污染有关;在中、高Pb、Hg、Cr、As及高Cu含量土壤组中,其重金属含量明显高于我国北方土壤的背景值;土壤中Pb-Cd、Pb-Hg、Cr-As、Cr-Cu、As-Cu的含量存在正相关趋势,而Hg-As则有负相关趋势,因而低Pb、低Hg、高Cr及高Cu含量的土壤样所占比例较高。综上表明,土壤中Pb、Cd、Hg、Cr、As、Cu的含量水平存在较弱的关联性,陕西花椒林地土壤中Pb、Hg、Cr、As、Cu含量在国标中的安全范围内,1个土壤样中的Cd含量达风险管控水平。

Distribution of Heavy Metals in the Soils of the Main Prickly Ash Production Area in Shaanxi Province

In order to determine the contents and safety levels of heavy metals in the soils of main prickly ash cultivation areas in Shaanxi Province,soil samples were collected from 17 prickly ash forests in Shaanxi Province.The contents of heavy metals in soil samples were determined by electric-coupled plasma mass spectrometry,the relevance and linear correlation among them were analyzed.The results showed that Pb,Hg,Cr,As,and Cu contents were all lower than the risk screening values in the national standard of China.However,the Cd content in the soil sample from Shipu Village in Fengxian County was higher than the maximum risk control value in the national standard.This may be related to Cd pollution.In the soil groups that had middle or high levels of Pb,Hg,Cr,and As and high level of Cu,the heavy metal contents of the soils were significantly higher than the background value of soil in northern China.Positive correlation trends were found between the following pairs of elements:Pb-Cd,Pb-Hg,Cr-As,Cr-Cu,As-Cu ,while Hg-As had a negative correlation trend.Therefore,the proportion of soil samples with low Pb,low Hg,high Cr and high Cu contents was high.It was concluded that there weak correlations existed among Pb,Cd,Hg,Cr,As,and Cu,and the contents of these elements in the soils of prickly ash were in the safe range of national standard.The content of Cd in one soil sample reached the level of risk control.