基于富集系数对蔬菜地土壤重金属的安全阈值研究

Study on safety threshold of heavy metals in vegetable soils based on bioaccumulation factor

收集了1993年以来我国设施蔬菜重金属污染研究文献中的数据,统计分析了不同环境条件下和不同蔬菜类型对于重金属富集能力的规律,利用富集系数反演符合蔬菜卫生标准的土壤重金属的污染阈值。研究结果表明:尽管土壤环境条件相同,但不同种类蔬菜中重金属的富集能力有明显差异,总体表现为叶菜类富集程度为最高,其次为根菜类,再者为茄果类;而在不同的土壤环境条件下,重金属的富集能力在同类型的蔬菜中也有所不同,其富集能力与土壤pH值的大小成反比。利用食品安全国家标准,反推出不同蔬菜类型相对应的不同环境条件下土壤中的重金属含量的安全阈值,发现我国现行的温室菜地土壤质量标准,较为适用于酸性土壤,而在中性和碱性土壤上表现为比较严格,应进行调整。

The data from the research literature on heavy metal pollution of facility vegetables in China since 1993 were collected,and the law of heavy metal enrichment capacity under different environmental conditions and for different vegetable types was statistically analyzed.The results showed that:under the same environmental conditions,different vegetables have different concentrations of heavy metals.The accumulation of heavy metals in vegetables is generally manifested as leaf vegetables>root vegetables>fruit.Under different environmental conditions,the enrichment capacity of the same type of vegetables for heavy metals is different.The higher the soil pH is,the smaller the enrichment coefficient of heavy metal elements in vegetables is.According to the national food safety standard,the safety threshold of heavy metal content in soil under different environmental conditions corresponding to different vegetable types is derived,and it is found that the current soil quality standard for greenhouse vegetable in China is more suitable for acidic soil,while it is more strict in neutral and alkaline soil,which should be adjusted.