The presence of mercury and other trace metals in surface soils in the Norwegian Arctic

Svalbard is an important study area for investigating the long-range transport of mercury (Hg) and other trace elements to the Arctic. Few studies have focused on their concentrations in Arctic soils. With ongoing climate change leading to thawing permafrost ground the soil compartment is of increasing importance in the Arctic. In this study, elemental composition and soil organic matter (SOM) content of surface and mineral soils in Svalbard are presented. The aim is to provide new data on soils in the Arctic and to gain more knowledge about the role of the soil in the biogeochemical cycle of mercury (Hg). Concentrations are reported for Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, S and Zn. Samples were taken in Adventdalen and in the area near Ny-angstrom lesund. We obtained a mean Hg concentration of 0.111 +/- 0.036 mu g/g in surface soils (range 0.041-0.254 mu g/g). Hg levels in mineral soils (mean: 0.025 +/- 0.013 mu g/g; range: 0.004-0.060 mu g/g) were substantially lower than in the corresponding surface soils. Hg strongly accumulates in the surface soil layer (upper 3 cm) and is associated with SOM (surface soil: 59 +/- 14%). Hg concentrations in the surface soil were slightly lower than those in the humus layer in mainland Norway and were comparable to levels in soils elsewhere in the Arctic. An inverse association of Hg was found with elements attributed to the mineral soil, indicating that Hg is predominantly derived from atmospheric deposition. (C) 2017 The Authors. Published by Elsevier Ltd.