华南花岗岩风化土壤中铊的生态风险和健康风险研究  

Ecological and Health Risks of Thallium in Weathered Granite Soils of Southern China

作　　者：何颖 孟凡德 肖新 张振国 肖唐付 HE Ying;MENG Fande;XIAO Xin;ZHANG Zhenguo;XIAO Tangfu(College of Resource and Environment,Anhui Science and Technology University,Chuzhou Anhui 233100,China;Key Laboratory for Water Quality and Conservation of the Pearl River Delta,Ministry of Education/School of Environmental Science and Engineering,Guangzhou University,Guangzhou 510006,China;School of Resources and Environment,Anqing Normal University,Anqing Anhui 246011,China)

机构地区：[1]安徽科技学院资源与环境学院,安徽滁州233100 [2]广州大学环境科学与工程学院,广州510006 [3]安庆师范大学资源与环境学院,安徽安庆246011

出　　处：《地球与环境》2024年第6期723-732,共10页Earth and Environment

基　　金：国家自然科学基金重点项目(41830753);环境地球化学国家重点实验室开放课题(SKLEG2023205)。

摘　　要：铊(Tl)作为一种非必需的重金属元素,对动植物及人体均表现出显著的毒害特性。在自然环境中,Tl主要赋存于低温热液硫化物及含钾硅酸盐矿物之中。特别是花岗岩,作为含钾硅酸盐矿物的重要载体,在自然风化成土的过程中会促使这些矿物的溶解,从而将Tl释放至地表环境,形成地质高背景。值得深入研究的是,不同地质时期的花岗岩中,含钾硅酸盐矿物及硫化物的含量存在显著的差异。然而,目前对于这种差异是否直接关联到土壤中Tl等重金属元素的生态风险,以及由此可能引发的潜在健康风险仍缺乏全面认识。本研究以华南地区三叠纪和侏罗纪花岗岩风化土壤为研究对象,深入探讨了重金属Tl的生态风险和潜在健康风险及其关键控制因素。研究结果显示,三叠纪和侏罗纪花岗岩风化土壤中,Tl含量及其生态风险指数存在明显差异性。此外,不同成岩期花岗岩风化土壤中种植的农作物对Tl的吸收累积能力也存在显著差异,进而导致Tl的健康风险指数差异。通过随机森林分析得知,花岗岩风化土壤中Tl的生态风险和健康风险主要受土壤中Tl、钾(K)和磷(P)分布的影响,而土壤中Tl、K和P含量分布差异受到两个不同时期花岗岩风化土壤化学组成的制约。研究结果为理解高地质背景地区重金属的生物地球化学行为提供了新认识,有助于科学评估土壤Tl的环境健康风险并为制定相应的环境管理措施提供依据。Thallium(Tl),as a non-essential heavy metal element,exhibits toxic effects to animals,plants,and humans.In nature,Tl primarily occurs in low-temperature hydrothermal sulfides and potassium-containing silicate minerals.The weathering of granite,as a particularly important carrier of potassium silicate minerals,may promote the dissolution of these minerals,thereby releasing Tl into the surface environment and leading to its high background level.Noticeably,granites from different geological periods contain varying amounts of potassium silicate minerals and sulfides.However,a comprehensive understanding of whether these differences are directly related to the ecological risks of Tl and other heavy metals in soils,and the potential health risks that may arise,is still lacking.This study focused on the weathered soils of Triassic and Jurassic granites in South China,exploring the ecological risks and potential health risks of Tl and its key controlling factors.The results show significant differences in Tl content and ecological risk indices between the weathered soils of Triassic and Jurassic granites.Additionally,the absorption and accumulation capabilities of crops planted in weathered soils from different granite periods vary significantly,leading to differences in Tl health risk indices.Random forest analysis indicates that the ecological and health risks of Tl in weathered granite soils are primarily influenced by the distribution of Tl,potassium(K),and phosphorus(P)in the soil.These distribution differences are constrained by the chemical composition of the weathered soils from the two different granite periods.These findings provide novel insights into the geochemical behavior of heavy metals in high geological background areas,contributing to a more comprehensive assessment of environmental and health risks and facilitating the implementation of appropriate management measures.

关 键 词：花岗岩 地质高背景土壤 铊 生态风险 健康风险 

分 类 号：X142[环境科学与工程—环境科学] X131