北京市怀柔区土壤重金属的分布特征、来源分析及风险评价
Distribution,Source Identification and Risk Assessment of Heavy Metals in Topsoil of Huairou District in Beijing

摘要： 在北京市怀柔区东南部农业区采集了977个表土样品，对其中Cr、V、Ni、As、Pb、Zn、Hg和Cd 8种重金属元素含量进行测试分析。通过地球化学成图清晰地呈现了这些元素的空间分布特征。利用数据统计分析，阐明了表土中这些重金属元素的含量分布特征，探讨了不同重金属的来源，并评估预测了其生态风险。研究结果表明Cr、V、Ni、As主要来源于成土母质；而Pb、Zn、Hg受交通和大气沉降等人类活动的影响较大；Cd则主要受到周边工厂以及农业施肥的影响。利用Hakanson法预测8种重金属的生态风险，除Cd外其他7种元素潜在生态风险均较低。本研究对怀柔区农业土壤的污染风险评价及土地利用规划具有一定的借鉴作用。
Abstract: At the agricultural area in the southeast of Huairou District in Beijing, 977 topsoil samples were collected, and 8 heavy metals in samples were analyzed, including Cr, V, Ni, As, Pb, Zn, Hg and Cd. The spatial distribution characteristics of these heavy metals were clearly illustrated by geochemical mapping. By applying the methods of multivariate statistics analysis, the concentration distributions of these heavy metals were dedicated, and the sources of them were determined, and risk assessment for them was also performed. The results show that the elements of Cr, V, Ni and As are mainly originated from soils parent materials. On the other hand, the elements of Pb, Zn and Hg are greatly influenced by the human activities, such as traffic and atmospheric deposition. Differently, Cd is mainly affected by inorganic fertilizer. The environmental risk of 8 heavy metals is assessed by Hakanson method, and all above heavy metals except Cd show a relatively low pollution risk. So, our study provides a significant reference for the risk assessment of agricultural soils and the future landusing plan at the area of Huairou District