Distribution and variability of total mercury in snow cover—a case study from a semi-urban site in Poznań, Poland

Abstract

In the present paper, the inter-seasonal Hg variability in snow cover was examined based on multivariate statistical analysis of chemical and meteorological data. Samples of freshly fallen snow cover were collected at the semi-urban site in Poznań (central Poland), during 3-month field measurements in winter 2013. It was showed that concentrations of atmospherically deposited Hg were highly variable in snow cover, from 0.43 to 12.5 ng L−1, with a mean value of 4.62 ng L−1. The highest Hg concentration in snow cover coincided with local intensification of fossil fuel burning, indicating large contribution from various anthropogenic sources such as commercial and domestic heating, power generation plants, and traffic-related pollution. Moreover, the variability of Hg in collected snow samples was associated with long-range transport of pollutants, nocturnal inversion layer, low boundary layer height, and relatively low air temperature. For three snow episodes, Hg concentration in snow cover was attributed to southerly advection, suggesting significant contribution from the highly polluted region of Poland (Upper Silesia) and major European industrial hotspots. However, the peak Hg concentration was measured in samples collected during predominant N to NE advection of polluted air masses and after a relatively longer period without precipitation. Such significant contribution to the higher Hg accumulation in snow cover was associated with intensive emission from anthropogenic sources (coal combustion) and atmospheric conditions in this area. These results suggest that further measurements are needed to determine how the Hg transformation paths in snow cover change in response to longer/shorter duration of snow cover occurrence and to determine the interactions between mercury and absorbing carbonaceous aerosols in the light of climate change.

Mercury Pollution In Snow Cover Around Thermal Power Plants In Cities (Omsk, Kemerovo, Tomsk Regions, Russia)

“…Generally, emissions can be transported locally, regionally, and globally and then deposited at any distance from its sources (Nelson et al 2010;Raputa et al 2010;Antonova et al 2019). Emissions of Hg into the air significantly affect snow cover chemical composition (Siudek et al 2014;Siudek 2016). It is important to assess snow pollution by Hg with great clarity at regional and local scales.…”