The cycle of mercury pollution in the Arctic tundra
Nature Human activity has been a major source of mercury pollution in the Arctic, and a new study has identified the form most often taken by the pollutant: gaseous elemental mercury (GEM). The present News & Views article discusses how the Arctic tundra acts as a major sink for mercury, as the local plants uptake GEM from the atmosphere; and what this means for the global mercury cycle as global temperatures warm. Isotopic data collected in the original study by Obrist et al. reveal that GEM accounts for 90% of the mercury in plants, and the uptake of GEM by plants is especially high in the summer. Since plant matter decomposes into the soil, the Arctic soil may soon become a substantial mercury sink. ======== Editor's summary Anthropogenic activities have led to large-scale mercury pollution in the Arctic, but it remains uncertain whether wet deposition of oxidized mercury via precipitation and sea-salt-induced ch