洪湖市某地区农水产品重金属含量特征及其安全性分析

Characteristics of the concentrations of heavy metals of agricultural and aquatic products in a certain area of Honghu City and its security analysis

基于洪湖市某地区水土地质环境特点和农产品特色进行农作物和水产品样品的布置和采集。根据样品的汞、镉、铅、砷、铬等元素含量测试结果,分析研究区农水产品中主要重金属元素含量分布特征,利用富集系数探讨根系土和底积物重金属含量异常的生态效应,参照相应食品重金属安全指标限值评价农水产品的安全性。结果表明:该区重金属生态危害较大,具有一定程度的污染;不同种类的农水产品内重金属含量顺序不同,说明不同农水产品对重金属的累计存在差异,稻谷和螃蟹的重金属含量一般高于鱼、藕带、莲子;生物对Cr和Pb的富集能力高于对As、Cd和Hg的富集能力,这与生物体对重金属元素的主动吸收和代谢有关。

On the basis of hydrogeologic characteristics of soil and water environment and variety of agricultural and aquatic products in Honghu City, this study conducted comprehensive analysis on distribution and characteristics of agricultural and aquatic products. The contents of heavy metals such as Hg, Cd, Pb, As and Cr were used to analyze the distribution features of these elements in agricultural and aquatic products. Meanwhile, the ecological effect of the abnormal heavy-metal concentrations in the root soil and sediments at bottom was discussed using enrichment coefficients and the security of agricultural and aquat- ic products in this area has also been evaluated by reference to the allowable maximum values of heavy metals in corresponding foods. The results show that concentrations of heavy metals have imposed ecological influence on this area to some extent. The sequences of the concentrations of heavy metal elements vary with types of agricultural and aquatic products, indicating that different agricultural and aquatic products differ in the accumulation of heavy metal elements. The concentrations of heavy metal elements in rice and crab are generally higher than that in fish, lotus root and lotus seed. Enrichment capability of creatures for chromium and lead is higher than that for arsenic, cadmium and mercury, which might be related to the creatures＇ active absorption for heavy metal elements and metabolic factors.