海洋汞同位素研究进展

Progresses in Study of Mercury Isotopic Compositions in the Ocean

海洋作为地球上最重要的汞储库之一,在调节全球汞循环中起着关键作用.近年来,汞同位素在研究海洋汞生物地球化学循环方面展现出明显优势,不但能示踪现代海洋汞污染来源及转化过程,还可重建古环境、古气候.总结了不同类型海洋样品汞同位素检测方法,系统归纳了其汞同位素数据,并重点阐述了海洋汞同位素分馏机制.总体上,目前海洋汞同位素数据还很有限,海洋汞循环关键过程的同位素分馏效应及潜在机理研究相对缺乏,精确源解析困难,难以对全球汞关键过程和循环通量进行准确验证和制约.未来还需要深入研究汞同位素分馏机理,进一步明确海洋中汞的来源、迁移及转化,为完善全球汞循环及精准防控海洋汞污染提供基础数据和理论支持.

Ocean,one of the most important reservoirs of mercury(Hg)on earth,plays a critical role in mediating the global Hg cycling.Recently,Hg isotope approach has shown significant advantages in studying the biogeochemical cycling of oceanic Hg,as it could be used not only to trace marine Hg sources and transformation processes,but also to reconstruct the paleoenvironment and paleoclimate.In this paper,it summarizes analytical methods for accurately measuring Hg isotopes in different marine samples,reported Hg isotopic compositions in seawater,marine sediments and biological samples of different regions worldwide,and elaborates the potential migration and transformation processes that fractionate Hg isotopes in the ocean.Overall,due to the fact that limited data are available for Hg isotopes in the ocean,and the studies on the potential mechanisms and processes fractionating Hg isotopes are still relatively scarce,the systematics of Hg in marine environment and thus the global Hg cycling model still could not be accurately established using Hg isotopes.In the future,it is still necessary to well investigate Hg isotope fractionation during potential biogeochemical processes such as the bioaccumulation and sedimentation,and to deeply decipher the source,migration and transformation of marine Hg using stable isotope approach,in order to provide basic data and theoretical support for improving the global Hg cycling and fairly preventing and controlling marine Hg pollution.