College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China.
Department of Environmental Science and Engineering, Sichuan University, Sichuan, 610065, China.
Environ Sci Pollut Res Int. 2023 Jan;30(4):10063-10078. doi: 10.1007/s11356-022-22847-7. Epub 2022 Sep 6.
Sewage irrigation has solved the shortage of agricultural water and increased the content of heavy metal(loid)s (HMs) in soil-crop systems, which harms human health via the food chain. In this study, 43 pairs of soil and corn samples (leaf, stem1, stem2, stem3, root, husk, grain, and corncob) were collected in the Dongdagou (DDG) and Xidagou (XDG) streams of Baiyin City. Fraction and transfer of As and Hg were investigated, and toxicological effects and contamination were assessed in soil-corn systems. The results showed that the mean values of As and Hg in soil were 33.79 mg/kg and 0.96 mg/kg, respectively, which exceeded the soil background values in Gansu Province. As and Hg are mainly dominated by the residual fraction. Total and bioavailability contributed significantly to As and Hg accumulation in corn, with root, stem3, and leaf accumulating more strongly. The results based on the bioavailability concentration soil-corn transfer factor indicated that As and Hg tended to accumulate more in the root, stem3, and leaf and less in grain, and further assessment of the human health effects of consuming contaminated cron is needed. Scanning electron microscope (SEM) and Fourier transform infrared (FTIR) results showed that As and Hg were not significantly toxic to corn parts, indicating morphology. As and Hg were bound to hydroxyl groups in the outer epidermal cell wall of the roots, thereby reducing upward translocation. The trinity assessment (TA) model results indicated that the most severe contamination was found in root and stem1. The TA provides a practical tool for soil-cron systems and helps develop management strategies to prevent ecological hazards.
污水灌溉解决了农业用水短缺问题，并增加了土壤-作物系统中重金属（类金属）（HMs）的含量，这些重金属通过食物链危害人类健康。本研究在甘肃省白银市东大沟（DDG）和西大沟（XDG）采集了 43 对土壤和玉米样品（叶、茎 1、茎 2、茎 3、根、壳、籽粒和玉米芯）。研究了砷和汞的形态和迁移，评估了土壤-玉米系统中的毒理学效应和污染。结果表明，土壤中砷和汞的平均值分别为 33.79mg/kg 和 0.96mg/kg，超过了甘肃省土壤背景值。砷和汞主要以残渣态为主。总态和生物可利用态对玉米中砷和汞的积累有显著贡献，根、茎 3 和叶积累的量更多。基于生物可利用态浓度-土壤-玉米转移系数的结果表明，砷和汞更倾向于在根、茎 3 和叶中积累，而在籽粒中积累较少，需要进一步评估食用受污染玉米对人体健康的影响。扫描电子显微镜（SEM）和傅里叶变换红外光谱（FTIR）结果表明，砷和汞对玉米各部分没有明显的毒性，表明形态。砷和汞与根外皮层细胞壁上的羟基结合，从而减少了向上的迁移。三位一体评估（TA）模型的结果表明，根和茎 1 的污染最严重。TA 为土壤-玉米系统提供了一种实用的工具，并有助于制定管理策略以防止生态危害。
