蔬菜中重金属含量及其评价

选取南昌市蔬菜批发市场中有代表性的3大类24品种243个蔬菜样本为监测对象,分析其中重金属Cu、Zn、Pb、Cd含量。结果表明,南昌市售蔬菜中均含有4种重金属,Cu、Zn含量较低,远低于食品卫生标准,部分样品存在Pb、Cd超标现象。在评价蔬菜中重金属含量对人体健康的影响时,不仅要正确评价重金属超标样品发生的可能性,还要评价多种重金属对蔬菜品质的安全程度。采用内梅罗指数对同一蔬菜品种中重金属含量进行表征,突出了最大超标样品的危害,能在一定程度上反映出重金属超标样品发生的可能性,较采用算术平均值表征其中重金属含量更为合理。同时,重金属污染土壤的评价方法(综合污染指数法)也能有效地反映蔬菜中多种重金属对其食用安全性的影响。评价结果说明,从食用蔬菜的安全角度考虑,多吃瓜果类蔬菜比吃叶菜和根茎类蔬菜更加安全。

The Heavy Metal Content in Vegetables and its Evaluation

The content of heavy metal,namely Cu,Zn,Pb and Cd in 3 kinds,24 species of vegetables including 243 samples,from Nanchang primary products markets was determined and analyzed.The results indicated that all of these vegetables had the four heavy metals and the contents of Cu and Zn were below the limit value of the food standard,while the contents of Pb and Cd in some samples exceeded the standard.In order to evaluate the effect of heavy metal content in vegetables on human health,we should consider not only the possibility of exceed samples but also the food safety of heavy metal to vegetables.The data process method of heavy metal in same sample by Nemero Index was much better than by arithmetic average value.It was mainly because the effect of the max heavy metal contents in the sample was emphasized by Nemero Index,and it accorded with the harm probability of heavy metal to vegetable quality.At the same time,the compound pollution index method used to evaluating contaminated soils was also suited to vegetables,because it can evaluate the whole effect of the four elements at the same time.According to the food security standard,people should eat more melon and fruit vegetables,and less foliage and rhizome vegetables.