The fate of mercury species in a sub‐arctic snowpack during snowmelt

Dommergue, Aurélien; Ferrari, Christophe; Gauchard, Pierre-Alexis; Boutron, Claude F.; Poissant, Laurier; Pilote, Martin; Jitaru, Petru; Adams, F.

doi:10.1029/2003gl017308

Cited by 116 publications

(141 citation statements)

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“…[76] In Amituk Lake in the Canadian High Arctic, snowmelt delivered the most THg during spring in June and early July [22,77] but 59 % of the THg delivered to Amituk Lake during the snowmelt period was directly discharged through lake outflow because of the limited mixing between surface and underlying water. [22] In Arctic regions, melt water concentrations of MeHg and THg were found to be elevated above full-column snowpack values at the onset of snow melt in some locations, [20,[77][78][79] but not all. [28] A summary of meltwater THg concentrations reported by six studies at nine sites across the Canadian and Greenland Arctic revealed a range from 0.3 to 10 ng L À1 with an average of ,3 ng L À1 .…”

Section: Since 1993 Prof Henrik Skov Has Worked As Principal Scientimentioning

confidence: 99%

“…[245] In contrast, it is now well established that the Hg deposited during AMDEs can be readily re-emitted from the snowpack during winter conditions following AMDEs [7,16,25,80,101,187,241,[246][247][248] and during snow metamorphism and melt. [20,79] Establishing a link between AMDEs and enhanced Hg levels in Arctic biota is complicated partly by a poor understanding of the net outcome of the AMDE deposition pathway, and partly by the complex Hg biogeochemistry of aquatic marine and fresh water ecosystems that contain inorganic Hg II from a variety of sources (of which AMDEs are but one) and methylate the inorganic Hg II into MeHg. Three lines of evidence pertaining to this question are reviewed here: the bioavailability of AMDE-deposited Hg, the amounts and fate of inorganic Hg inputs from AMDEs compared with those from other entry pathways and comparison of the spatial patterns of AMDE occurrence and biotic Hg concentrations.…”

Section: Eastern Beaufort Sea Belugamentioning

confidence: 99%

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The fate of mercury in Arctic terrestrial and aquatic ecosystems, a review

Douglas

Loseto²,

Macdonald³

et al. 2012

Environ. Chem.

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124

147

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Environmental context. Mercury, in its methylated form, is a neurotoxin that biomagnifies in marine and terrestrial foodwebs leading to elevated levels in fish and fish-eating mammals worldwide, including at numerous Arctic locations. Elevated mercury concentrations in Arctic country foods present a significant exposure risk to Arctic people. We present a detailed review of the fate of mercury in Arctic terrestrial and marine ecosystems, taking into account the extreme seasonality of Arctic ecosystems and the unique processes associated with sea ice and Arctic hydrology.Abstract. This review is the result of a series of multidisciplinary meetings organised by the Arctic Monitoring and Assessment Programme as part of their 2011 Assessment 'Mercury in the Arctic'. This paper presents the state-of-the-art knowledge on the environmental fate of mercury following its entry into the Arctic by oceanic, atmospheric and terrestrial pathways. Our focus is on the movement, transformation and bioaccumulation of Hg in aquatic (marine and fresh water) and terrestrial ecosystems. The processes most relevant to biological Hg uptake and the potential risk associated with Hg exposure in wildlife are emphasised. We present discussions of the chemical transformations of newly deposited or transported Hg in marine, fresh water and terrestrial environments and of the movement of Hg from air, soil and water environmental compartments into food webs. Methylation, a key process controlling the fate of Hg in most ecosystems, and the role of trophic processes in controlling Hg in higher order animals are also included. Case studies on Eastern Beaufort Sea beluga (Delphinapterus leucas) and landlocked Arctic char (Salvelinus alpinus) are presented as examples of the relationship between ecosystem trophic processes and biologic Hg levels. We examine whether atmospheric mercury depletion events (AMDEs) contribute to increased Hg levels in Arctic biota and provide information on the links between organic carbon and Hg speciation, dynamics and bioavailability. Long-term sequestration of Hg into non-biological archives is also addressed. The review concludes by identifying major knowledge gaps in our understanding, including:(1) the rates of Hg entry into marine and terrestrial ecosystems and the rates of inorganic and MeHg uptake by Arctic microbial and algal communities; (2) the bioavailable fraction of AMDE-related Hg and its rate of accumulation by biota and (3) the fresh water and marine MeHg cycle in the Arctic, especially the marine MeHg cycle.

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Section: Since 1993 Prof Henrik Skov Has Worked As Principal Scientimentioning

confidence: 99%

Section: Eastern Beaufort Sea Belugamentioning

confidence: 99%

The fate of mercury in Arctic terrestrial and aquatic ecosystems, a review

Douglas

Loseto²,

Macdonald³

et al. 2012

Environ. Chem.

Self Cite

124

147

View full text Add to dashboard Cite

show abstract

“…Similarly, Outridge et al (2008) concluded that there is no firm evidence that AMDEs exert a significant influence on mercury concentrations in the Arctic Ocean. However, Lindberg et al (2002), Dommergue et al (2003), Loseto et al (2004), Bargagli et al (2005), , Faïn et al (2007), Brooks et al (2008a), Douglas et al (2008), , Mitchell et al (2008b), Hirdman et al (2009), and Dommergue et al (2010), who conducted field campaigns at a variety of polar and lower latitudes, all determined that mercury deposited onto snowpacks was only partially revolatilized and could have an important impact on the environment. The partial revolatilization was reported for mercury deposited both in and not in association with AMDEs.…”

Section: Introductionmentioning

confidence: 99%

“…At the onset of snowmelt, the rates of photoreduction and revolatilization of GEM to the atmosphere increase significantly (Dommergue et al, 2003;Faïn et al, 2007;Sommar et al, 2007;Brooks et al, 2008b;Douglas et al, 2008), causing…”

Section: Introductionmentioning

confidence: 99%

How relevant is the deposition of mercury onto snowpacks? – Part 2: A modeling study

Durnford¹,

Dastoor

Ryzhkov

et al. 2012

Atmos. Chem. Phys.

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Abstract. An unknown fraction of mercury that is deposited onto snowpacks is revolatilized to the atmosphere. Determining the revolatilized fraction is important since mercury that enters the snowpack meltwater may be converted to highly toxic bioaccumulating methylmercury. In this study, we present a new dynamic physically-based snowpack/meltwater model for mercury that is suitable for large-scale atmospheric models for mercury. It represents the primary physical and chemical processes that determine the fate of mercury deposited onto snowpacks. The snowpack/meltwater model was implemented in Environment Canada's atmospheric mercury model GRAHM. For the first time, observed snowpack-related mercury concentrations are used to evaluate and constrain an atmospheric mercury model. We find that simulated concentrations of mercury in both snowpacks and the atmosphere's surface layer agree closely with observations. The simulated concentration of mercury in both in the top 30 cm and the top 150 cm of the snowpack, averaged over 2005-2009, is predominantly below 6 ng L −1 over land south of 66.5°N but exceeds 18 ng L −1 over sea ice in extensive areas of the Arctic Ocean and Hudson Bay. The average simulated concentration of mercury in snowpack meltwater runoff tends to be higher on the Russian/European side (>20 ng L −1 ) of the Arctic Ocean than on the Canadian side (<10 ng L −1 ). The correlation coefficient between observed and simulated monthly mean atmospheric surface-level gaseous elemental mercury (GEM) concentrations increased significantly with the inclusion of the new snowpack/meltwater model at two of the three stations (midlatitude, subarctic) studied and remained constant at the third (arctic). Oceanic emissions are postulated to produce the observed summertime maximum in concentrations of surface-level atmospheric GEM at Alert in the Canadian Arctic and to generate the summertime volatility observed in these concentrations at both Alert and Kuujjuarapik on subarctic Hudson Bay, Canada. We find that the fraction of deposited mercury that is revolatilized from snowpacks increases with latitude from 39 % between 30 and 45°N, to 57 % from 45 to 60°N, 67 % from 60 to 66.5°N, and 75 % polewards of 66.5°N on an annual basis. Combining this latitudinal gradient with the latitudinally increasing coverage of snowpacks causes yearly net deposition as a fraction of gross deposition to decrease from 98 % between 30 and 45°N to 89 % between 45 and 60°N, 73 % between 60 and 66.5°N, and 44 % within the Arctic Circle. The yearly net deposition and net accumulation of mercury at the surface within the Arctic Circle north of 66.5°N are estimated at 153 and 117 Mg, respectively. We calculate that 58 and 50 Mg of mercury are deposited annually to the Arctic Ocean directly and indirectly via melting snowpacks, respectively. For terrestrial surfaces within the Arctic Circle, we find that 29 and 16 Mg of mercury are deposited annually directly and indirectly via melting snowpacks, respectively. Within the Arctic Circle, multi-s...

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“…Greenland surface air temperature trends, including at the Summit site, have not shown persistent warming since 1930 in contrast to global average surface temperature (23). Liquid water in snowpacks could enhance GEM emission (e.g., during snowmelt) (26), but occurrences of surface snow melting at Summit are extremely improbable. Similarly, important changes in solar irradiation at Summit during the last century are unlikely.…”

mentioning

confidence: 99%

Polar firn air reveals large-scale impact of anthropogenic mercury emissions during the 1970s

Faïn

Ferrari

Dommergue

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

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Mercury (Hg) is an extremely toxic pollutant, and its biogeochemical cycle has been perturbed by anthropogenic emissions during recent centuries. In the atmosphere, gaseous elemental mercury (GEM; Hg°) is the predominant form of mercury (up to 95%). Here we report the evolution of atmospheric levels of GEM in mid-to high-northern latitudes inferred from the interstitial air of firn (perennial snowpack) at Summit, Greenland. GEM concentrations increased rapidly after World War II from Ϸ1.5 ng m ؊3 reaching a maximum of Ϸ3 ng m ؊3 around 1970 and decreased until stabilizing at Ϸ1.7 ng m ؊3 around 1995. This reconstruction reproduces real-time measurements available from the Arctic since 1995 and exhibits the same general trend observed in Europe since 1990. Anthropogenic emissions caused a two-fold rise in boreal atmospheric GEM concentrations before the 1970s, which likely contributed to higher deposition of mercury in both industrialized and remotes areas. Once deposited, this toxin becomes available for methylation and, subsequently, the contamination of ecosystems. Implementation of air pollution regulations, however, enabled a large-scale decline in atmospheric mercury levels during the 1980s. The results shown here suggest that potential increases in emissions in the coming decades could have a similar large-scale impact on atmospheric Hg levels.atmosphere ͉ Greenland ͉ past century ͉ pollution

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The fate of mercury species in a sub‐arctic snowpack during snowmelt

Cited by 116 publications

References 13 publications

The fate of mercury in Arctic terrestrial and aquatic ecosystems, a review

The fate of mercury in Arctic terrestrial and aquatic ecosystems, a review

How relevant is the deposition of mercury onto snowpacks? – Part 2: A modeling study

Polar firn air reveals large-scale impact of anthropogenic mercury emissions during the 1970s

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