【摘要】 【目的】以城市化发展影响下广州城区零散菜地土壤为研究对象,研究重金属的污染特征及其生态风险。【方法】采集广州市7个中心城区35个土壤样品,分析As、Cd、Cr、Cu、Hg、Ni、Pb、Zn 8种重金属的浓度,采用Pearson相关系数、主成分分析法、潜在生态危害指数法分析了土壤中重金属的来源、含量和生态风险。【结果】研究区菜地土壤As、Cd、Cr、Cu、Hg、Ni、Pb、Zn的含量均值分别为15.93、0.11、66.37、46.84、0.62、35.19、110.09、154.95 mg/kg,均高于背景值。与《土壤环境质量标准》比较,除Cr外,其余金属均出现不同程度的超标,并以Hg的超标率最高(37.1%)。菜地土壤重金属污染源为复合型人为污染源。部分菜地土壤处于较高的生态危害水平,Hg是主要的风险元素。【结论】广州城区部分零散菜地土壤不再适宜种植蔬菜。更多还原

【Abstract】 [Objective]This paper was to study the pollution characteristics and ecological risk of heavy metals in vegetable soils of Guangzhou urban districts, which have been impacted by the development of urbanization. [Method]35 soil samples were collected from 7 central districts in Guangzhou to analyze the concentrations of As, Cd, Cr, Cu, Hg, Ni, Pb and Zn. Pearson correlation coefficient, principal component analysis and potential ecological risk index were used to study the sources, contents, and ecological risk of heavy metals in soil.[Result]The average contents of As, Cd, Cr, Cu, Hg,Ni, Pb and Zn in vegetable soils were 15.93, 0.11, 66.37, 46.84, 0.62, 35.19, 110.09 and 154.95 mg/kg, respectively, all of which were higher than the background values. Comparing with Environmental Quality Standard for Soils, the contents of all metals(except Cr) exceeded the standard values to different extent, with the exceeding rate of Hg being the highest(37.1%).The pollution sources of heavy metals in vegetable soil were compound artificial pollution sources. Some vegetable soils in Guangzhou urban districts were at a high level of ecological hazard and Hg was the main risk element.[Conclusion]Some vegetable soils in Guangzhou urban districts were no longer suitable for vegetable cultivation.更多还原