Seasonal variations of Cd, Pb, Cu and Ni levels in snow from the eastern Arctic Ocean

During the Swedish Arctic expedition “Ymer 80” into the area from North Greenland to Franz-Josef-Land in late sumnier 1980, freshly fallen snow, and snow from the previous fall/winter season were collected from ice floes. Lead. cadmium and copper analysis was performed on board ship, using I he advanced voltammetric determination method of differential pulse anodic stripping voltammeuy at rotating glassy carbon electrodes. The analytic operations were performed under a clean bench in a clean room container. Nickel. and tentatively. cobalt levels were analyzed in our home laboratory by differential pulse voltammetry after preconcentration by chelate adsorption at a hanging mercury drop electrode. Results from freshly fallen snow compared to snow from the previous season show that there exists a strong seasonal variation in trace metal deposition, indicating that pollution of the Arctic atmosphere is clearly limited to winter time, when atmospheric conditions favour long-distance transport of polluted air masses from Europe to the Arctic. Unexpectedly low mean levels of 0.4 ng kg^-1 Cd. 13 ng kg^-1 Pb, 20 ng kg^-1 Cu and 22 ng kg^-1 Ni were found in freshly fallen snow. levels that represent about 1/10 to 1/20 ofthose in annual condensed layers.