Spatial trends of trace-element contamination in recently deposited lake sediment around the Ni-Cu smelter at Nikel, Kola Peninsula, Russian Arctic.

A large copper-nickel smelter complex is located at the Kole Penninsula, Russia, close to the Norwegian border. Trace-element concentrations in surface sediments (0-0.5 cm) and pre-industrial sediments from 45 lakes in the region were used to uncover spatial deposition patterns and contamination factor of sediments. Elevated concentrations were found, especially for Ni and Cu, but also for Pb, Co, Hg, As, and Cd. Highest concentrations were found up to 20 km from the smelter, but the concentrations decreased exponentially with distance from the smelter. Increasing Ni, Cu, As, and Hg concentrations from sub-surface to surface sediments were found for lakes at intermediate distances (20-60 km). This may reflect recent changes in atmospheric depositions, as shown in nearby Norwegian areas. However, we cannot rule out that this also may have been caused by diagenetic processes, especially for the most redox-sensitive elements such as As.