广西某污染区金属元素在土壤-植物系统中的迁移规律

Transfer patterns of metal elements in soil-plant system in a contaminated area in Guangxi,China

重金属镉(Cd)是一种毒性极强并广泛存在于环境中的有害元素。土壤中的Cd极易被植物吸收并通过食物链对普通人群的健康造成危害。由于Cd在土壤-植物系统的迁移及对人类健康的影响与某些金属元素之间存在着相互作用,研究这些元素对Cd在食物链中迁移及在人体内富集的影响机制成为Cd研究的热点。本研究对广西某污染区的菜田进行了调查,结果表明:污染区蔬菜的Cd、Ca、Cu、Fe、Pb、Zn的浓度明显高于非污染区;不同的蔬菜品种对重金属元素Cd、Cu、Pb、Zn的迁移和积累能力存在着较大差异,不同金属元素的迁移能力依次为Cd>Zn>Cu>Pb;Cd在土壤-植物中的迁移受共存元素的影响。

Heavy metal cadmium （Cd） is a very toxic element ubiquitous in the environment. The Cd in soil is easily absorbed by plants, and consequently, produces adverse effects on human health through food chain. Owing to the fact that the Cd transfer in soil-plant system and the adverse effects of Cd on human health are influenced by the interactions between Cd and some other metal elements, e.g. , Ca, Cu, Fe, and Zn, the study on the mechanisms of the influences of these elements on Cd transfer through food chain and the accumulation of Cd in human body becomes a hotspot. In this study, a survey was performed on the vegetable field in a Cd-contaminated area in Guangxi. The results showed that in contaminated area, the concentrations of Cd, Ca, Cu, Fe, Pb, and Zn in vegetables were obviously higher than those in uncontaminated area, and different vegetable varieties had greater differences in the absorption and accumulation of Cd, Cu, Pb, and Zn. The transferring ability of these four metal elements in soil-plant system was Cd 〉 Zn 〉 Cu 〉 Pb, and the transfer of Cd was affected by the elements in coexistence.