Mu Demiao, Zheng Shunan, Lin Dasong, Xu Yingming, Dong Ruyin, Pei Penggang, Sun Yuebing
Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, Ministry of Agriculture and Rural Affairs (MARA), Agro-Environmental Protection Institute, MARA, Tianjin 300191, China; Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Agro-Environmental Protection Institute, MARA, Tianjin 300191, China.
Rural Energy & Environment Agency, MARA, Beijing 100125, China.
Sci Total Environ. 2023 May 15;873:162171. doi: 10.1016/j.scitotenv.2023.162171. Epub 2023 Feb 10.
Excessive dietary intake of cadmium (Cd) poses toxicity risks to human health, and it is therefore essential to establish accurate and regionally appropriate soil Cd thresholds that ensure the safety of agricultural products grown in different areas. This study investigated the differences in the Cd accumulation in 32 vegetable varieties and found that the Cd content ranged from 0.01 to 0.24 mg·kg, and decreased in the order of stem and bulb vegetables > leafy vegetables > solanaceous crops > bean cultivars. A correlation analysis and structural equation model showed that pH, soil organic matter, and the cation exchange capacity had significant effects on Cd accumulation in the vegetables and explained 72.1 % of the variance. In addition, species sensitivity distribution (SSD) curves showed that stem and bulb vegetables were more sensitive to Cd than other types of vegetables. Using the Burr Type III function for curve fitting, we derived Cd thresholds of 6.66, 4.15, and 1.57 mg·kg for vegetable soils. These thresholds will ensure that 20 %, 50 %, and 95 % of these vegetable varieties were risk-free, respectively. The predicted threshold of soil Cd was more than twice that of China's current National Soil Quality Standard (GB 15618-2018) for Cd values. Therefore, soil scenarios and cultivars should be considered comprehensively when determining farmland soil thresholds. The present results provide a new model for setting soil Cd criteria in high geological background areas.
膳食中镉（Cd）摄入量过高会对人体健康构成毒性风险，因此，确定准确且适用于不同地区的土壤镉阈值对于确保不同地区种植的农产品安全至关重要。本研究调查了32个蔬菜品种镉积累的差异，发现镉含量范围为0.01至0.24mg·kg，且按茎类和鳞茎类蔬菜＞叶菜类蔬菜＞茄科作物＞豆类品种的顺序递减。相关分析和结构方程模型表明，pH值、土壤有机质和阳离子交换容量对蔬菜中镉的积累有显著影响，解释了72.1%的变异。此外，物种敏感性分布（SSD）曲线表明，茎类和鳞茎类蔬菜对镉的敏感性高于其他类型蔬菜。使用Burr III型函数进行曲线拟合，我们得出蔬菜土壤的镉阈值分别为6.66、4.15和1.57mg·kg。这些阈值将确保分别有20%、50%和95%的蔬菜品种无风险。预测的土壤镉阈值超过了中国现行镉值的国家土壤质量标准（GB 15618-2018）的两倍多。因此，在确定农田土壤阈值时应综合考虑土壤情况和品种。目前的结果为高地质背景地区土壤镉标准的设定提供了一个新模型。
