Winter atmospheric deposition of trace elements in the Arkhangelsk region (NW Russia): Insights into environmental effects

Atmospheric precipitation is an important indicator of ecological status. Snow cover accumulates all atmospheric precipitation that occurs during the cold season and releases large amounts of matter into surface water streams during spring snowmelt. We measured chemical composition of suspended solids (>0.45 μm) and dissolved matter (<0.45 μm) of atmospheric precipitation sampled on a monthly basis in 4 stations of Arkhangelsk region in cold seasons of 2018–2021. The fluxes of insoluble particles increase consistently in the spring months. In winter, the largest fluxes of suspended solids from the atmosphere were observed in the urbanized areas (in Severodvinsk and Onega). Snow in Onega showed a significant enrichment in Mn as well as Rb, Sr, Cs, Ba and Pb, which is related to boiler house emissions. Severodvinsk snow is enriched in V, Ni in dissolved fraction and Al, V, Cu, Sr, Pb in suspended solids. The environmental risk assessment shows that Onega station is affected to high and extremely polluted conditions for Mn concentration and Severodvinsk station is affected to multi-element pollution from moderate to significant levels. Comparison with the composition of the river runoff of the Northern Dvina showed that the concentrations of Cu, Zn, Cd and Pb in the snow are equal to or even higher than the river concentrations, indicating that atmospheric precipitation accumulated during winter can significantly affect the geochemistry of river runoff with respect to these elements.