An Shaoshan
The Research Center of Soil and Water Conservation and Ecological Environment, Chinese Academy of Sciences and Ministry of Education, Yangling, China.
Environ Geochem Health. 2025 Jul 9;47(8):309. doi: 10.1007/s10653-025-02621-7.
The effects of human activities on heavy metal pollution in agricultural soils have been less investigated on the Qinghai-Xizang Plateau. The present study was designed to assess the potential sources and contamination risks of heavy metals (Cr, Cd, Pb, As and Hg) in agricultural soils in three typical agricultural counties in the Huangshui River Basin of the Plateau, a total of 520 samples of agricultural soil were taken from the surface over two years. Heavy metals data were systematically analyzed by GIS mapping, positive matrix factorization (PMF) and risk assessments methods. The results showed that the heavy metal concentrations in the soil of all three counties were below the risk screening value of soil contamination of agricultural land in China. The main source pathways of heavy metals were identified based on the PMF model, with Hg as atmospheric deposition, Cr, Pb, and As as soil parent materials, and Cd as fertilizer application and industrial activities. Cr, Pb, and As exhibited no contamination and posed low ecological risk due to minimal accumulation, while posed a carcinogenic risk through oral intake; some of the sample sites for Cd and Hg had high concentrations and posed some ecological risk, but there was no health risk from any exposure. The integrated assessment of multiple risk assessment methods is more conducive to pollution risk control of heavy metals. Reduction of Cd and Hg should be recognized as an important component of soil pollution management strategies and action plans for cultivated soils.
人类活动对青藏高原农业土壤重金属污染的影响鲜有研究。本研究旨在评估青藏高原湟水河流域三个典型农业县农业土壤中重金属（铬、镉、铅、砷和汞）的潜在来源及污染风险，在两年内共采集了520个表层农业土壤样本。采用地理信息系统制图、正定矩阵因子分解（PMF）和风险评估方法对重金属数据进行系统分析。结果表明，三个县土壤中的重金属浓度均低于中国农用地土壤污染风险筛选值。基于PMF模型确定了重金属的主要来源途径，汞为大气沉降，铬、铅和砷为土壤母质，镉为施肥和工业活动。铬、铅和砷未表现出污染，由于积累量极少，生态风险较低，但经口摄入会带来致癌风险；部分镉和汞采样点浓度较高，存在一定生态风险，但任何暴露途径均无健康风险。多种风险评估方法的综合评估更有利于重金属污染风险管控。应将降低镉和汞含量作为耕地土壤污染治理策略和行动计划的重要组成部分。
