Hg distribution and speciation in Antarctic soils of the Fildes and Ardley peninsulas, King George Island

Abstract Data on the content and speciation of mercury (Hg) in the soils of Antarctica are scarce and vary greatly between the regions studied, but overall Hg concentrations found were generally very low. We investigated the Hg quantity and speciation by solid-phase Hg pyrolysis and chemical fractio...

Full description

Bibliographic Details
Published in:Antarctic Science
Main Authors: De Andrade, Renato Pereira, Michel, Roberto Ferreira Machado, Schaefer, Carlos Ernerto Gonçalves Reynaud, Simas, Felipe Nogueira Bello, Windmöller, Cláudia Carvalhinho
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 2012
Subjects:
Online Access:http://dx.doi.org/10.1017/s0954102012000107
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102012000107
Description
Summary:Abstract Data on the content and speciation of mercury (Hg) in the soils of Antarctica are scarce and vary greatly between the regions studied, but overall Hg concentrations found were generally very low. We investigated the Hg quantity and speciation by solid-phase Hg pyrolysis and chemical fractionation in selected maritime Antarctic soils, comparing ornithogenic and non-ornithogenic areas of the Fildes and Ardley peninsulas of King George Island. The total Hg contents ranged from 4.3–256 ng g -1 , and values for ornithogenic soils were the highest recorded for Antarctic soils. A close correlation between Hg and organic matter was observed in the ornithogenic soils, with levels decreasing with depth. In the non-ornithogenic soils, a correlation between Hg content and soil depth was also observed, but the values were found to increase with depth. Thermograms showed that all Hg was in the 2 + oxidation state and was predominantly linked to organic matter, corroborating the chemical fractionation results for the ornithogenic soils. These results show the need for further refined studies about the interactions of Hg with organic matter in order to better understand the biogeochemistry of this metal in the Antarctic environment.