textLower atmospheric aerosols have been characterized for the period of 1964-1978
in the European sub Arctic region at Kevo, northern Finland. A total of 685 weekly
samples were analyzed for Ag, Al, As, Br, Ca, Cl, Co, Cu, I, In, K, Mn, Na, Sb, Si, Sn,
Ti, V, W, and Zn using neutron activation analysis. Study of time series concentration
levels, box plots of the monthly subsets, and the descriptive statistics of seasonal datasets
showed that seasonal weather had less influence in the lower atmospheric elemental
concentration levels at Kevo. Two very distinct silver concentration level periods, high
and low, were observed in the Kevo atmosphere during 1964-1970 and 1971-1978. A
comparison of anthropogenic elemental concentration levels in the Kevo lower
atmosphere were found in the same range or 2-8 fold higher than reported literature data
of Russian and Canadian Arctic during winter and spring seasons. Elements like In, Cu,
Zn, As, Sb, Sn, and Ag were highly enriched in the Kevo lower atmosphere. Principal
component factor analysis showed a strong smelting factor consisting of copper, zinc,
indium, and tin. This factor was found to be more important in the principal component
factor analysis (PCFA) in winter dataset than that of summer. A crustal factor was easily
recognized in the winter PCFA results, but crustal components were mixed up with
industrial components in the summer results. Sea source components appeared in a
single factor in the summer PCFA results but were found in pairs into several factors in
winter results. Antimony was mostly found in a single factor. The Unmix model was
used to identify sources and source composition in the Kevo atmosphere. Residence time
analysis was used for identifying the source location of all elements using an air parcel
back trajectory ensemble. The impact of this research is three fold. First, it’s contribution
to the ongoing Arctic research. Second, the modeling experience obtained from this very
large dataset could be used for future research and monitoring. Third, the development of
new NAA methodologies for determining important industrial marker elements, like
silver and cobalt, and the development of a new scheme for cost-effective determination
of medium lived isotopes.Mechanical Engineerin