广州市蔬菜重金属污染现状及对人体健康风险分析

Health Risk of Heavy Metals to The General Public in Guangzhou, China via Consumption of Vegetables

通过测定3个不同采样时期广州市主要蔬菜市场的12种蔬菜共36个样品,分析其中的Pb、Cd、Cr、Ni、Cu、Zn重金属含量水平,对经蔬菜途径摄入的重金属暴露接触人体的健康风险进行了评估。结果显示,Pb、Cr、Cd为广州市蔬菜的主要污染元素,其超标率分别达到22.2%、38.9%和13.9%。根茎类蔬菜的污染程度大于叶菜类和瓜果类。利用单因子污染指数法进行了评价,发现广州市蔬菜的污染比例在50%以上,其中28.9%为轻度污染。广州市居民经食用蔬菜日均Pb、Zn、Cd、Cu、Cr、Ni摄入量(Daily intake,DI)均未超过FAO/WHO人均日摄入可允许限量标准(Provisional tolerable daily intake,PTDI)。THQ(Target hazard quotients)靶标危害系数结果表明几种重金属的THQ值均小于1,其中Pb的THQ为0.447,说明经蔬菜途径摄入重金属对广州市居民健康风险很低,但是与其他几种元素相比,Pb在一定程度上具有潜在风险。

36 vegetable samples including 12 most popular vegetable types were taken in three different seasons from the Jiangnan Vegetable Wholesale Market-the biggest vegetable consumption market in Guangzhou City, and analyzed for heavy metal contents of Pb, Cd, Cr, Ni, Cu, and Zn. Results showed that Pb,Cr,Cd were the major heavy metal contaminants of vegetables in Guangzhou, with 22.2%, 38.9% and 13.9% of tested samples above the Safety Requirements for Non-environmental Pollution Vegetable respectively, while rhizome vegetables exhibited higher degree of contamination than leaf vegetables and melons. Single-factor contaminant index was utilized for assessment. It was found that over 50% vegetables in Guangzhou were contaminated, of which 28.9% were classified as slightly contaminated. The Health risks associated with these heavy metals were assessed based on the target hazard quotients （THQs）, which can be derived from concentrations of heavy metals in vegetables consumed in the inhabitants. The THQs of heavy metals of vegetables in Guangzhou was below 1, which indicated that the health risk via vegetable consumption in Guangzhou was relative low. While compared to other heavy metals, more attention should be pay to Pb, the metal with the highest THQ of 0.447.