Sheng Weikang, Hou Qingye, Yang Zhongfang, Yu Tao, Zhan Long, Zhang Ming, Zhou Mo, Chen Guoguang, Tang Zhimin, Wang Ying
School of Earth Science and Resources, China University of Geosciences, Beijing, 100083, China.
School of Earth Science and Resources, China University of Geosciences, Beijing, 100083, China.
Environ Res. 2025 Jul 1;285(Pt 1):122251. doi: 10.1016/j.envres.2025.122251.
Soil is a vital and fragile natural resource in the Earth's surface system, with the accumulation of potentially toxic elements (PTEs), such as Cd and Pb, drawing global environmental concern. Soil convergent evolution may lead to the homogenization of major elemental compositions; however, the main mechanisms controlling the distributions of PTEs in soils remain insufficient. Furthermore, the combined effects of pedogenesis and anthropogenic activities on the geochemical behaviors of PTEs are still poorly understood. The results exhibited a high degree of development of the studied soils, with the median Cd and Pb concentration were 0.143 and 47.40 mg/kg in topsoil, respectively. The exceedance rates of Pb in topsoil is 18.22 % indicating that Pb posed broader pollution risks than Cd. The soil Cd concentration exhibited a gradual accumulation at lower slope positions, whereas Pb reached its highest concentration in mid-upper slope areas. Results from Positive Matrix Factorization (PMF) analysis revealed that rock weathering is the primary sources of Cd and Pb, contributing approximately 69.6 % and 70.3 %, respectively. Terrain played a key role in influencing soil physicochemical properties, consequently leading to Cd and Pb spatial heterogeneity. Moreover, mountain barriers facilitated Cd and Pb accumulation on windward slopes along prevailing wind direction. Mining activities accelerated the release and diffusion of PTEs, with airborne pollutants further dispersing PTEs on a large scale. This study provides critical insights into the mechanisms governing soil PTE s pollution from pedogenesis perspective, offering valuable guidance for long-term soil quality monitoring and management in high-altitude and hilly regions.
土壤是地球表面系统中一种至关重要且脆弱的自然资源，镉（Cd）和铅（Pb）等潜在有毒元素（PTEs）在土壤中的积累引发了全球环境关注。土壤趋同演化可能导致主要元素组成的同质化；然而，控制土壤中PTEs分布的主要机制仍不充分。此外，成土作用和人为活动对PTEs地球化学行为的综合影响仍知之甚少。结果表明，所研究的土壤发育程度较高，表层土壤中Cd和Pb的中位浓度分别为0.143和47.40 mg/kg。表层土壤中Pb的超标率为18.22%，表明Pb比Cd带来更广泛的污染风险。土壤Cd浓度在较低坡度位置呈现逐渐积累的趋势，而Pb在中上坡区域浓度最高。正定矩阵因子分解（PMF）分析结果表明，岩石风化是Cd和Pb的主要来源，分别贡献了约69.6%和70.3%。地形在影响土壤理化性质方面起关键作用，从而导致Cd和Pb的空间异质性。此外，山脉屏障促进了Cd和Pb沿盛行风向在迎风坡的积累。采矿活动加速了PTEs的释放和扩散，空气中的污染物进一步大规模扩散PTEs。本研究从成土作用角度为控制土壤PTEs污染的机制提供了关键见解，为高海拔和丘陵地区的长期土壤质量监测和管理提供了有价值的指导。
