海洋汞同位素的研究范式及最新进展  

The paradigm and recent progress in studying marine mercury isotopes

作　　者：孙若愚 李程皓 李松旌 王钊[1] 陈筱玮 袁晶晶 刘羿 SUN Ruo-yu;LI Cheng-hao;LI Song-jing;WANG Zhao;CHEN Xiao-wei;YUAN Jing-jing;LIU Yi(Institute of Surface-Earth System Science,School of Earth System Science,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学地球系统科学学院,表层地球系统科学研究院,天津300072

出　　处：《矿物岩石地球化学通报》2024年第4期689-705,I0002,共18页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家重点研发计划项目(2022YFF0800300);国家自然科学基金资助项目(42173011,42373011)。

摘　　要：汞(Hg)是一种具有生物毒性且能够全球传输的重金属元素,在海洋环境中易转化为神经毒素甲基汞并沿食物网进行富集和放大,危害生态系统和人类健康。准确约束海洋汞的来源、迁移与转化是理解海洋汞循环的关键,对更新现有海洋汞循环模型和制定相关环境政策具有重要价值。近十多年发展起来的汞稳定同位素技术为研究环境中的汞循环以及生态环境效应开辟了新视野。汞同位素独特的“三维”分馏模式,特别是非质量分馏(MIF),为研究海洋汞循环带来了科学范式的改变,取得了一系列重要发现。本文从海洋汞的来源以及甲基汞的生成、迁移与转化两大方面的应用系统阐述了近十多年来汞同位素体系在示踪海洋汞循环方面的主要进展,重点剖析了汞同位素在远洋大气汞沉降途径以及甲基汞循环方面的应用等近期研究热点。未来需结合更精细的汞同位素测试手段以及汞同位素分馏控制实验进一步明确海洋汞同位素分馏的主要控制因素,拓展汞同位素的应用空间。Mercury(Hg)is a heavy metal that is biologically toxic and can be transported globally as a gas.In the marine environment,Hg is easily converted to the neurotoxin methyl-Hg which bioaccumulates and biomagnifies through the food web,posing risks to ecosystems and human health.Accurately constraining the source,migration,and transformation of marine Hg is crucial for understanding the Hg cycle and has significant value in updating existing marine Hg cycling models and formulating relevant environmental policies.Over the past decade,the development of Hg stable isotope techniques has provided novel insights into the study of Hg cycling in the environment,as well as the related ecological effects.The unique“three-dimensional”fractionation pattern of Hg isotopes,especially the mass independent fractionation(MIF)has brought about a paradigm shift to the study of marine Hg cycling and achieved a series of important discoveries.In this study,we systematically review the recent progress of Hg isotope system in tracing marine Hg cycling,including the sources of Hg in oceans and the generation,transport and transformation of methyl-Hg.Specifically,we provide a key analysis and outlook on recent research hotspots,such as the atmospheric depositional pathways and the cycling of methyl-Hg in open oceans.We recommend that the future research should combine more sophisticated Hg isotope measurement tools and more environmentally relevant Hg isotope fractionation control experiments to further clarify the main controlling factors of marine Hg isotope fractionation and expand the application of Hg isotopes.

关 键 词：汞稳定同位素 非质量分馏 甲基汞 沉降途径 深海 

分 类 号：P595[天文地球—地球化学]