Mercury in the Canadian Arctic Terrestrial Environment: An Update
2015 (English)In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 509-510, 28-40 p.Article in journal (Refereed) Published
Contaminants in the Canadian Arctic have been studied over the last twenty years under the guidance of the Northern Contaminants Program. This paper provides the current state of knowledge on mercury (Hg) in theCanadian Arctic terrestrial environment. Snow, ice, and soils on land are key reservoirs for atmospheric deposition and can become sources of Hg through the melting of terrestrial ice and snow and via soil erosion. In the Canadian Arctic, new data have been collected for snow and ice that provide more information on the net accumulation and storage of Hg in the cryosphere. Concentrations of total Hg (THg) in terrestrial snow are highly variable but on average, relatively low (less than 5ng/L), and methylmercury (MeHg) levels in terrestrial snow are also generally low (less than 0.1 ng/L). On average, THg concentrations in snow on Canadian Arctic glaciers are muchlower than those reported on terrestrial lowlands or sea ice. Hg in snow may be affected by photochemical exchanges with the atmosphere mediated by marine aerosols and halogens, and by post-depositional redistribution within the snow pack. Regional accumulation rates of THg in Canadian Arctic glaciers varied little during the past century but show evidence of an increasing north-to-south gradient. Temporal trends of THg in glacier cores indicate an abrupt increase inthe early 1990s, possibly due to volcanic emissions, followed by more stable, but relatively elevated levels. Little information is available on Hg concentrations and processes in Arctic soils. Terrestrial Arctic wildlife typically have low levels of THg (less than μg/g dry weight) in their tissues, although caribou(Rangifer tarandus) can have higher Hg because they consume large amounts of lichen.THg concentrations in the Yukon’s Porcupine caribou herd vary among years but there has been no significant increase or decrease over the last two decades.
Place, publisher, year, edition, pages
2015. Vol. 509-510, 28-40 p.
Arctic, Mercury, Snow, Glacier, Wildlife, Temporal trend
Research subject Earth Science with specialization in Environmental Analysis
IdentifiersURN: urn:nbn:se:uu:diva-230140DOI: 10.1016/j.scitotenv.2014.04.070ISI: 000350521700004PubMedID: 24861531OAI: oai:DiVA.org:uu-230140DiVA: diva2:738993