Mercury isotope signatures as tracers for environmental Hg cycling

Autor(en)

Jan Georg Wiederhold

Abstrakt

Mercury (Hg) is a toxic pollutant element. Due to its use in many anthropogenic processes and its global biogeochemical cycling, elevated Hg levels are found in many ecosystems worldwide. Different Hg species exhibit a wide range of physico-chemical properties and understanding species transformation processes is therefore essential for assessing Hg mobility and bioavailability. Many aspects of the environmental behavior and fate of Hg are still poorly understood, for instance the relative importance of different transformation mechanisms and the allocation of different anthropogenic Hg sources.

Investigating the relative distribution of the seven stable Hg isotopes offers a new approach for tracing Hg sources and transformations [1]. Mercury isotope “signatures” can be determined with high precision (≤0.1‰, 2SD) by cold-vapor-MC-ICP-MS and are influenced by mass-dependent (MDF, δ202Hg) and mass-independent fractionation (MIF, Δ199Hg). In the last decade, >100 publications have documented large Hg isotope variations in natural samples and reported fractionation factors and mechanisms for a variety of processes [2].

I will give an overview on the development and future challenges of the application of Hg isotopes as environmental tracers. The known mechanisms causing MIF of odd-mass Hg isotopes (Fig.1) either by the non-linear increase of nuclear charge radii (NVE) or their non-zero nuclear spin and magnetic moment (MIE) will be discussed and new puzzling observations of MIF of even-mass Hg isotopes presented. Examples of own recent work on boreal forest soils and industrial contamination cases will illustrate the potential of Hg isotope signatures as novel source and process tracers in environmental studies.

 

Organisation(en)

Publikationsdatum

07-2017

ÖFOS 2012

105105 Geochemie, 105906 Umweltgeowissenschaften, 105904 Umweltforschung

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/45f16a42-03e0-4da6-b084-7399f6dcdf4d