基于体外模拟法评价蔬菜中Cd的健康风险与污染土壤修复效果

Human health risk assessment of Cd in vegetables and the remediation effect of Cd-polluted soil evaluated using an in-vitro simulation test

为探明北方地区常见蔬菜中Cd的健康风险,以北京地区Cd污染的大棚菜地土壤为对象,利用盆栽实验测定了韭菜和小油菜对Cd的吸收、转运特征及2种修复剂(沸石+蚯蚓粪,凹凸棒+蚯蚓粪)对Cd污染土壤的修复效果,基于体外模拟法和人体健康风险评价方法对污染土壤修复前、后的2种蔬菜中Cd的有效性及人体健康风险进行评价。结果表明,污染土壤上的2种蔬菜中Cd含量均超过《食品安全国家标准食品中污染物限量》,但2种蔬菜对Cd的吸收具有显著差异,小油菜中Cd的含量为韭菜的2.04倍;体外模拟法测定结果表明,韭菜和小油菜中Cd在模拟人体胃液中的有效浓度分别为0.027、0.039 mg·kg-1,韭菜中的Cd对人体具有更高的生物有效性;基于人体健康风险评价方法对2种蔬菜中Cd进行健康风险评价,结果表明,污染土壤上种植的2种蔬菜中Cd对人体具有较高的致癌风险,其中,对0~6岁儿童的致癌风险大于成人(>18岁)的风险;添加修复剂可使韭菜和小油菜中Cd含量最大分别降低65.2%和72.3%;2种修复剂处理的韭菜与小油菜中Cd的生物有效性和致癌风险值显著下降,其中凹凸棒+蚯蚓粪处理土壤的2种蔬菜中Cd的致癌风险值接近安全水平。

Cd-polluted field soil was collected from a greenhouse in Beijing and a pot experiment was conducted to investigate the uptake and accumulation of Cd by leek and rape.The bioavailability of Cd in human gastric juice and human health risk of Cd in vegetables grown on Cd-polluted soil and soil remediated with amendments(zeolite+earthworm manure,attapulgite+earthworm manure)were determined using an in-vitro simulation test and by health risk assessment,respectively.The results indicated that the Cd content in the both vegetables exceeded the National Food Safety Standard and that there was a significant difference in the uptake content of Cd between the vegetables.The Cd content in rape was 1.04 times higher than that in leek.According to the in-vitro simulation test,the bioavailable Cd content in leek and rape reached 0.027,0.039 mg·kg-1 fresh weight,indicating that Cd in leek is more available for human than that in rape.The carcinogenic risk of Cd to human body was observed for the both vegetables based on the health risk assessment.Moreover,the carcinogenic risk to children aged 0~6 years was higher than that to adults aged>18 years.The maximum decrease in the Cd content in leek and rape grown on soil treated with amendments was 65.2%and 72.3%,respectively,compared with that in the corresponding controls.Further,the bioavailability and carcinogenic risk of Cd in leek and rape decreased significantly with different soil amendment treatments,and the carcinogenic risk value of Cd approached the safety level in the both vegetables grown on soil treated with a mixture of attapulgite and earthworm manure.