Snow contamination by heavy metals and metalloids in a polar town (a case study of Nadym, Russia)

Abstract

The article presents the results of a study of snow composition in the town of Nadym (Western Siberia) During the studies conducted in 2021–2022, we determined dust load, concentrations and ratio of dissolved and suspended forms of metals and metalloids (MMs). In the background area, the snow composition depends on the long-range transport of pollutants. We analyzed air mass trajectories using the HYSPLIT model, and the analysis showed the industrial regions of the southern Urals, southeastern Siberia, and Kazakhstan to be the sources of MMs. The content of the insoluble fraction increases 23 times in the town. The dust load in Nadym is higher than in the urban communities situated in the temperate climate zone, although the town is smaller in population and has no large industrial enterprises. A significant increase in the dust load in the town leads to a ten- and hundredfold increase in the content of many MMs. Local soils (Fe, Al), vehicles (W), building dust (Mg, Ca), and anti-icing agents (Na) are the sources of pollution. We showcase that the high dust load is caused by meteorological factors which reduces the dispersion of pollution, such as temperature inversions and a large number of calm days. The case of Nadym demonstrates that winter air quality in polar settlements can be worse than in urban areas in the temperate zone even with few pollution sources. The trend towards an increase in the number of windless days, observed in Siberia as a result of global climate change, increases the risk of anthropogenic pollution of the atmosphere of polar cities.