Trends and source apportionment of atmospheric heavy metals at a subarctic site during 1996–2018 (original) (raw)

2020, Atmospheric Environment

AI-generated Abstract

Atmospheric trace elements (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, Zn) in particulate matter have been measured since 1996 at Pallas, a subarctic site in Finland. The results indicate a very low level of pollution as the concentrations were among the lowest measured in Europe. The annual average concentration during the whole time series, from the lowest values to the highest, was Co < Cd < Cr < As < V < Ni < Cu < Mn < Pb < Zn < Al < Fe, ranging from 0.02 to 20 ng m À 3. For the priority elements As, Cd, Ni and Pb, the annual average concentration was 0.10, 0.02, 0.21 and 0.65 ng m À 3, respectively, in 2018. The concentrations were compared with the results from three other sites in Finland, and a clear south-to-north decreasing gradient was found for most elements except for Ni, which was found to be mostly associated with emissions from the Kola Peninsula. Several elements were attributed to long-range transport (LRT) pollutants, while others related to soil origin. A comprehensive trend analysis revealed statistically significant decreasing trends for several heavy metals up to 64% during the study period, with continued declines since 2010. No significant increasing trends were observed.