摘要
对栖霞市苹果产地土壤重金属Cd、Hg、As、Pb、Cr、Cu、Zn和Ni的含量进行了调查分析,并采用单项质量指数与综合质量指数相结合的方法对环境质量状况进行了评价。结果表明,栖霞市苹果产地土壤中各重金属的平均含量均低于"食用农产品产地环境质量评价标准"(HJ332—2006)规定的限值,土壤环境质量定为1级,属于清洁水平,适宜发展无公害苹果。但部分监测点的土壤样品重金属含量超标,除As和Pb以外,其他元素均出现了超标情况,超标率介于3.23%～9.68%之间。与山东省棕壤自然背景值相比,土壤中Hg、Cu、Cd、Zn、Ni和As等6种元素均出现了累积现象。除As与Ni外,其他元素之间多呈显著或极显著正相关关系。结合主成分分析的结果,推测As和Ni的含量主要受成土母质的影响,而其他6种元素受人类活动影响比较大。栖霞市苹果产地土壤存在可能引起复合污染的风险,建议进一步加强对肥料和农药使用的管理和限制,最大程度地降低环境风险。
Contents of heavy metals Cd, Hg, As, Pb, Cr, Cu, Zn and Ni in soils （0-20 cm）of apple farmland in Qixia city were investigated. The environmental quality was evaluated by methods of single quality index and comprehensive quality index. Results showed that the average contents of heavy metals in soils were all under the threshold prescribed by ＂Farmland environmental quality evaluation standards for edible agricultural products＂（HJ332--2006）. The heavy metal contents varied greatly among different sites. The coefficient of variation （C.V.） of Cd was the highest, being 90.41%. While the C.V.of As was the lowest, being 10.86%. The single quality indices of the eight elements were all lower than 0.7, among which Ni had the highest value 0.68, followed by Cu, Hg, Zn, Cd, Cr, Pb and As. In combination with the comprehensive quality index of the eight elements（0.56 ）, the environmental quality of soils in apple farmland of Qixia was classified as the first class belonging to clean level and fit for the plantation of non-environmental pollution apple. However, contents of heavy metals, except As and Pb, in some of the soil samples went beyond the standards, and the percent was between 3.23% and 9.68%. Compared with the background values of brown soils of Shandong Province, average contents of the six elements, Hg, Cu, Cd, Zn, Ni and As, were higher than the standards and showed accumulation in the soil. Contents of Cd, Hg, As, Cu, Zn or Ni in more than 70% of soil samples were higher than the background values. Most of the heavy metals were significantly positively correlated in contents, except As and Ni. And the cmTelations between Pb and Cd, Cd and Zn, Zn and Cu, Zn and Cr, Cu and Cr were the strongest（P〈0.001 ）. Results of main component analysis of the single quality indices of the eight elements showed that the first and second components could explain 82.51% of the total variance and their eigenvalues were all larger than 1. As and Ni belonged to the second components, and the other six elements belonged to the first components. It was suggested that As and Ni were mainly affected by soil parent material, while the others were mainly affected by human activities. The risk of multiplex pollution might exist in soils of Qixia. To reduce environmental risk effectively, the management of fertilizer and pesticide use were proposed to be strengthened.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2008年第6期2274-2278,共5页
Journal of Agro-Environment Science
基金
山东省农业科学院博士基金项目(2006YBS015)
山东农科院高技术自主创新基金项目(2007ycx023-01)
关键词
重金属
土壤
环境质量
评价
heavy metal
soil
environmental quality
evaluation
