Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
Xi'an University of Finance and Economics, Xi'an 710100, China.
Sci Total Environ. 2022 Jul 20;831:154863. doi: 10.1016/j.scitotenv.2022.154863. Epub 2022 Mar 26.
Toxic elements (TEs) in soil threaten the eco-environmental system and human health. The identification and prediction of sources and high-risk areas of TEs in soil are fundamental for regional pollution prevention and control. In this study, geostatistical methods and GIS-based approaches were used to quantitatively analyze the spatial distribution, geochemical characteristics, key driving factors, and their interactive effects of TEs in soil from a typical area of the Tethys-Himalaya tectonic domain in Tibet based on an integrated approach combining positive matrix factorization and GeoDetector models. The mean contents of chromium, arsenic (As), cadmium, mercury and lead in the soil exceeded the Tibetan background values, with 66.20% of As being higher than the screening values. The spatial distribution of TEs content in the soil was primarily affected by geogenic source factors (primarily geology types, soil parent materials, soil types, and soil pH), and environmental source factors (primarily precipitation and vegetation types) and anthropogenic source factors (primarily income of residents and land-use types) also had the same contribution approximately. Compared with that for individual driving factors, the interaction between most pairs of driving factors enhanced their explanatory power. The high-risk areas for soil As pollution were primarily distributed in the valley areas of the upper reaches of the Longzi River Basin. Therefore, to guarantee the health of residents and the security and sustainability of agricultural production in the study area, regular monitoring and soil remediation should be used to reduce the migration and transformation of As in the local biogeochemical cycle. This study provides new ideas for the regional prediction of high-risk areas for soil pollution, which has guiding importance and reference value for the control and management of large-scale soil pollution.
土壤中的有毒元素（TEs）威胁着生态环境系统和人类健康。识别和预测土壤中 TEs 的来源和高风险区域是区域污染预防和控制的基础。本研究采用地统计学方法和基于 GIS 的方法，结合正矩阵因子分解和地理探测器模型，对青藏高原特提斯喜马拉雅构造域典型地区土壤中 TEs 的空间分布、地球化学特征、关键驱动因素及其相互作用进行了定量分析。土壤中铬、砷（As）、镉、汞和铅的平均含量超过了西藏背景值，其中 66.20%的 As 高于筛选值。土壤中 TEs 含量的空间分布主要受地球成因源因素（主要是地质类型、土壤母质、土壤类型和土壤 pH 值）的影响，环境源因素（主要是降水和植被类型）和人为源因素（主要是居民收入和土地利用类型）也有相同的贡献。与单一驱动因素相比，大多数对驱动因素之间的相互作用增强了它们的解释能力。土壤 As 污染的高风险区主要分布在隆子河流域上游的河谷地区。因此，为了保障研究区居民的健康以及农业生产的安全和可持续性，应定期进行监测和土壤修复，以减少当地生物地球化学循环中 As 的迁移和转化。本研究为区域土壤污染高风险区预测提供了新思路，对大规模土壤污染的控制和管理具有指导意义和参考价值。
