Wei Yanyan, Zheng Xiaoman, Shohag Md Jahidul Islam, Gu Minghua
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Cultivation Base of Guangxi Key Laboratory for Agro-Environment and Agro-Products Safety, College of Agriculture, Guangxi University, Nanning 530004, China.
Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou 310058, China.
Int J Environ Res Public Health. 2017 Aug 29;14(9):977. doi: 10.3390/ijerph14090977.
In many countries cadmium (Cd) and arsenic (As) commonly coexist in soils contaminated by mining activities, and can easily enter the human body via consumption of leafy vegetables, like the popularly consumed pakchoi ( L.), causing major health concerns. In the present study, bioaccessibility and human exposure of Cd and As were assessed in twenty genotypes of pakchoi cultured at two different levels of co-contamination to identify low health risk genotypes. The bioaccessibilities of Cd and As represent a fraction of the total metals content could be bioaccessible for human, in the present study, significant differences in pakchoi Cd and As bioaccessibility were observed among all tested genotypes and co-contaminated levels. Cd and As bioaccessibility of pakchoi were in the ranges of 24.0-87.6% and 20.1-82.5%, respectively, for in the high level co-contaminated soils, which was significantly higher than for low level co-contaminated soils with 7.9-71.8% for Cd bioaccessibility and 16.1-59.0% for As bioaccessibility. The values of bioaccessible established daily intakes (BEDI) and the total bioaccessible target hazard quotients (TBTHQ) of Cd and As were also considerably higher in high level co-contaminated soils than in low level co-contaminated soils. Two genotypes (Meiguanqinggengcai and Zhenqing60F1) contained relatively low concentrations and bioaccessible Cd and As and, their BEDI and TBTHQ for Cd and As ranged below the tolerable limits set by the FAO/WHO (BEDI of Cd < 0.83 μg kg bw day, BEDI of As < 3 μg kg bw day) and United States Environmental Protection Agency (TBTHQ for Cd and As < 1), this applied for both levels of co-contaminated soils for adults and children. Consequently, these findings suggest identification of safe genotypes in leafy vegetable with low health risk via genotypic screening and breeding methods could be a useful strategy to ensure the safety of food crops grown in those Cd and As co-contaminated fields due to mining activities.
在许多国家，镉（Cd）和砷（As）在受采矿活动污染的土壤中普遍共存，并可通过食用叶菜类蔬菜，如人们普遍食用的小白菜（Brassica rapa L.），轻易进入人体，引发重大健康问题。在本研究中，对在两种不同共污染水平下培养的20种小白菜基因型中的镉和砷的生物可及性及人体暴露情况进行了评估，以确定低健康风险基因型。镉和砷的生物可及性代表了人体可生物利用的总金属含量的一部分，在本研究中，所有测试基因型和共污染水平之间小白菜镉和砷的生物可及性存在显著差异。在高污染水平土壤中，小白菜镉和砷的生物可及性分别在24.0 - 87.6%和20.1 - 82.5%范围内，显著高于低污染水平土壤，低污染水平土壤中镉的生物可及性为7.9 - 71.8%，砷的生物可及性为16.1 - 59.0%。高污染水平土壤中镉和砷的生物可及性确定的每日摄入量（BEDI）值和总生物可及性目标危害商（TBTHQ）也显著高于低污染水平土壤。两种基因型（梅关青梗菜和真青60F1）的镉和砷含量及生物可及性相对较低，其镉和砷的BEDI和TBTHQ低于粮农组织/世界卫生组织设定的耐受限值（镉的BEDI < 0.83 μg kg bw day，砷的BEDI < 3 μg kg bw day）以及美国环境保护局设定的限值（镉和砷的TBTHQ < 1），这适用于成人和儿童的两种共污染水平土壤。因此，这些研究结果表明，通过基因型筛选和育种方法鉴定低健康风险叶菜类蔬菜中的安全基因型，可能是确保在因采矿活动而镉和砷共污染的田地里种植的粮食作物安全的有用策略。
