A 6,000-years record of atmospheric mercury accumulation in the high Arctic from peat deposits on Bathurst Island, Nunavut, Canada

There is a growing interest in the atmospheric transport, deposition, and accumulation of anthropogenic Hg in the Arctic. To quantify the impact of industrial Hg emissions, the natural rate of atmospheric Hg accumulation must be known. Mercury concentration measurements and age dating of peat from the Canadian Arctic show that natural background Hg flux rather constant (ca. 1 microgram per sq. m per yr.) throughout the past 6000 years. Mercury concentrations in surface peat layers are much higher, but chronology of these changes cannot be interpreted until more age dates are available. The elevated Hg concentrations in surface layers, however, are out of proportion with Br and Se, suggesting that there has been a significant human impact. Peat cores from southern Canada provide a record of atmospheric Hg accumulation extending back nine thousand years, with similar background fluxes. Thus, pre-anthropagenic Hg fluxes in the High Arctic were not significantly different from atmospheric Hg fluxes in the temperate Zone.