Mercury in Arctic marine ecosystems: Sources, pathways and exposure

Environment Canada, Aquatic Contaminants Research Division, 867 Lakeshore Dr, Burlington, ON, Canada L7R 4A6. Electronic address: .
Environmental Research (Impact Factor: 4.37). 10/2012; 119. DOI: 10.1016/j.envres.2012.08.012
Source: PubMed


Mercury in the Arctic is an important environmental and human health issue. The reliance of Northern Peoples on traditional foods, such as marine mammals, for subsistence means that they are particularly at risk from mercury exposure. The cycling of mercury in Arctic marine systems is reviewed here, with emphasis placed on the key sources, pathways and processes which regulate mercury levels in marine food webs and ultimately the exposure of human populations to this contaminant. While many knowledge gaps exist limiting our ability to make strong conclusions, it appears that the long-range transport of mercury from Asian emissions is an important source of atmospheric Hg to the Arctic and that mercury methylation resulting in monomethylmercury production (an organic form of mercury which is both toxic and bioaccumulated) in Arctic marine waters is the principal source of mercury incorporated into food webs. Mercury concentrations in biological organisms have increased since the onset of the industrial age and are controlled by a combination of abiotic factors (e.g., monomethylmercury supply), food web dynamics and structure, and animal behavior (e.g., habitat selection and feeding behavior). Finally, although some Northern Peoples have high mercury concentrations of mercury in their blood and hair, harvesting and consuming traditional foods have many nutritional, social, cultural and physical health benefits which must be considered in risk management and communication.

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    • "This finding extends the geographic limits of the trend previously observed in multiple tissues of different bird species in the Arctic (e.g., Braune et al., 2002; Akearok et al., 2010; Øverjordet et al., 2015). Increasing Hg in eggs of marine birds at higher latitudes is driven by complex environmental factors including source Hg from local geology, global atmospheric deposition patterns, air and ocean circulation patterns , and climate-influenced retention of Hg in Arctic ice reservoirs (see Kirk et al., 2012, and references therein). Despite that Hg represents an issue for wildlife health in the northeastern USA and Nova Scotia regions (e.g., Goodale et al., 2008), the maximum level of Hg in Nova Scotia eider eggs (0.16 μg/g ww) was similar to that found in Maine (0.18 μg/g ww; Mierzykowski et al., 2005) and was 60% lower than the " no adverse effect " level (0.4 μg/g ww) determined for a variety of bird species (Shore et al., 2011). "
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    ABSTRACT: We provide the first report on trace element concentrations in eggs of common eiders (Somateria mollissima), a coastal benthic foraging sea duck, from Nova Scotia, Canada, and compare those to known values from this species elsewhere. Most trace elements of toxicological concern (Hg, Se, Cd, Cu, Zn) were lower in eider eggs from Nova Scotia than from eider eggs collected farther north in Canada, although As was elevated. Our data provide strong support for a pattern of increasing Hg at higher latitudes for this species.
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    • "The presence of persistent organic pollutants (POPs) and metals in the blood and other tissues of people from the Canadian Arctic and other circumpolar nations is well documented. Although there are natural and point sources of these chemicals (Kirk et al., 2012), global pollution and long-range atmospheric transportation are the main sources in the Arctic (Macdonald et al., 2000). Because of their physical–chemical properties, these chemicals can biomagnify through the marine food web system and can reach high concentrations in predatory species such as marine mammals (Borgå et al., 2004; Braune et al., 2005). "
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    • "Sediments collected in the Barents Sea contained little total mercury (3–5 ng/g d.w.), which corresponds to the lowest values observed in the Beaufort Shelf (1–130 ng/g) and along the Greenland coast (4–280 ng/l) (Asmund and Nielsen, 2000; Kirk et al., 2012 "
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