沈阳张士灌区六种蔬菜的镉污染

Cd pollution of six vegetable species in wastewater irrigation area of Zhangshi, Shenyang

在张士Cd污灌区蔬菜种植地采集了6种季节性蔬菜(莴笋、辣椒、茄子、花椰菜、西红柿和大葱)及土壤样品,进行了Cd含量分析,采用超标倍数法评价了蔬菜可食部Cd的吸收积累,采用富集系数和转移系数法评价了Cd从土壤至蔬菜的吸收转运能力。结果表明:在6种蔬菜中,莴笋、辣椒和茄子的可食部Cd较高,分别为4.01、1.78和1.24mg·kg-1DW;其可食部Cd分别超标1.92、2.28和2.01倍(叶菜类标准0.20mg·kg-1FW,茄果类标准0.05mg·kg-1FW);西红柿、花椰菜和大葱可食部Cd未超标,分别为1.02、1.20和0.83mg·kg-1DW;花椰菜、大葱和西红柿的富集系数分别为0.28、0.36和0.52,符合低积累蔬菜标准,莴笋的富集系数1.26,在张士及类似污染水平土壤中种植将产生较大生态风险。

Six seasonal vegetable species （lettuce,pepper,eggplant,cauliflower,tomato and welsh onion） and soil samples were collected from the vegetable growing farmland of Zhangshi wastewater irrigation area for Cd analysis.The uptake and accumulation ability of Cd in the edible part of the vegetable was evaluated using overproof multiple method,and the enrichment coefficient （EE） and translocation coefficient （TC） was employed to assess the efficiency of Cd uptake and transportation from soil to vegetables.Results indicated that Cd concentrations in the edible parts of lettuce,pepper and eggplant were higher among the six vegetables investigated,being 4.01,1.78 and 1.24 mg·kg-1 DW,respectively.The overproof amount of Cd in the edible part of these vegetables corresponded to 1.92,2.28 and 2.01 times of that of the national food limited standards （0.20 mg·kg-1 FW for leaf vegetables,and 0.05 mg·kg-1 FW for solanaceous vegetables）.Cd concentrations in the edible part of the rest vegetables were within the national food limited standards.The Cd concentration was 1.02,1.20 and 0.83 mg·kg-1 DW for tomato,cauliflower and welsh onion,respectively,with EE of 0.28,0.36 and 0.52,respectively,which matched to the standard for low accumulated vegetables.EE was higher for lettuce with a value of 1.26,which indicated a comparatively large eco-risk if lettuce is to plant in Zhangshi soil or soil with similar Cd concentration level.