Organic Matter in Rain: An Overlooked Influence on Mercury Deposition

Abstract

The importance of Hg emissions for deposition will be scrutinized in the future as new legislation to control emissions of Hg to the atmosphere comes into effect. We show that mercury (Hg) concentrations in rainfall are closely linked to organic matter (OM) with consistent Hg/TOC ratios over large spatial scales decreasing from that in an open field (OF, 1.5 mu g g(-1)) to that in throughfall (TF, 0.9 mu g g(-1)). The leaf area index was positively correlated with both TF [Hg] and total organic carbon ([TOC]), but not the Hg/TOC ratio. This study shows that the progression in the Hg/TOC ratio through catchments starts in precipitation with Hg/TOCbulk dep > Hg/TOCsoil (water) > Hg/TOCstreamwater These findings raise an intriguing question about the extent to which it is not just atmospheric [Hg] but also OM that influences [Hg] in precipitation. This question should be resolved to improve the ability to discern the importance of changing global Hg emissions for deposition of Hg at specific sites.

Published in

Environmental Science and Technology Letters
2015, volume: 2, number: 4, pages: 128-132
Publisher: AMER CHEMICAL SOC

SLU Authors

• Åkerblom, Staffan

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Bishop, Kevin

  • Uppsala University

Associated SLU-program

Non-toxic environment
SLU Future Forests

UKÄ Subject classification

Environmental Sciences

Publication identifier

• DOI: https://doi.org/10.1021/acs.estlett.5b00009

Permanent link to this page (URI)

https://res.slu.se/id/publ/73438