College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China.
China National Environmental Monitoring Centre, Beijing 100012, China.
Int J Environ Res Public Health. 2022 Aug 31;19(17):10843. doi: 10.3390/ijerph191710843.
The spatial distributions of Cr, Ni, Cu, Zn, As, Cd and Pb (potentially toxic elements, PTEs) in sediments and intrinsic influence factors from the Wuliangsuhai wetland of the Hetao Irrigation District, China were studied in this work. The results showed that excluding Zn, the total contents of other PTEs were higher than the background values, of which As (39.26 mg·kg) and Cd (0.44 mg·kg) were six-fold and seven-fold higher, respectively. Especially, the high levels of Cd (70.17%), Pb (66.53%), and Zn (57.20%) in the non-residual fraction showed high bioavailability and mobility. It indicated that PTEs can enter the food chain more easily and produce much toxicity. Based on , ICF, and MRI, the contamination of As was the most serious in the middle areas (MDP) of the wetland, and its risk was up to moderately strong. Cd and Pb posed moderate and considerate risk, respectively. Furthermore, 29.50% and 55.54% risk contribution ratio of As and Cd, respectively, showed that they were the dominant contaminants. In addition, the positive correlation between sand, OM, and total contents and chemical fractions of PTEs by using PCM, RDA, and DHCA indicated that physicochemical properties could significantly influence the spatial distributions of PTEs. The work was useful for assessing the level of pollution in the study area and acquiring information for future and possible monitoring and remediation activities.
本研究对中国河套灌区乌梁素海湿地沉积物中铬（Cr）、镍（Ni）、铜（Cu）、锌（Zn）、砷（As）、镉（Cd）和铅（Pb）（潜在有毒元素，PTEs）的空间分布及其内在影响因素进行了研究。结果表明，除 Zn 外，其他 PTE 总量均高于背景值，其中 As（39.26mg·kg）和 Cd（0.44mg·kg）分别高出 6 倍和 7 倍。特别是非残渣态中 Cd（70.17%）、Pb（66.53%）和 Zn（57.20%）含量较高，具有较高的生物可利用性和迁移性。这表明 PTEs 更容易进入食物链并产生更大的毒性。基于 ICF、MRI 和潜在生态风险指数（RI），湿地中部（MDP）As 的污染最严重，风险达到中度偏强。Cd 和 Pb 分别构成中度和可考虑风险。此外，As 和 Cd 的风险贡献率分别为 29.50%和 55.54%，表明它们是主要污染物。此外，PCM、RDA 和 DHCA 分析表明，PTEs 总量和化学形态与砂、OM 之间存在显著正相关，说明理化性质可显著影响 PTEs 的空间分布。该研究对评估研究区的污染水平以及为未来可能的监测和修复活动提供信息具有重要意义。
