DISTRIBUTION OF ISOTOPES, MACRO- AND MICROELEMENTS FROM ATMOSPHERIC FALLOUT IN LICHENS OF ARCTIC ZONE OF WESTERN SIBERIA - FIRST DATA

The relevance of the study is determined by the beginning of active industrial development of Russia's Arctic territories. For a correct assessment of anthropogenic impact. it is necessary to know the regional levels of geochemical background, as well as the pathways of atmospheric transport of substance. Lichens are widely used as bioindicators not only of anthropogenic pollution. but also of significant natural processes, for example, local or global atmospheric transport and biogeochemical processes of redistribution of elements. The main aim: to determine the concentrations of micro- and macroelements (Mg, Al, Si, P, K, Ca, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Sr, Zr, Cd, Ba, La, Ce, Eu, Pb, Nb, Mo, Nd, Hf, Ta, W, Th, U, Sn, REE), natural and artificial isotopes (Be-7, Pb-210, (137)cs) in lichens and their distribution between lichens biomass fractions. Objects: lichens from foresttundra of the Arctic zone of Western Siberia: Yamalo-Nenets Autonomous Okrug, Novy Urengoy region. Methods: sequential elution techniques for lichen biomass with separation of four fractions: stable elements determination - ICP-AES and ICP-MS; natural and artificial isotopes determination - gamma-spectrometry with using well detector. Results. The concentrations of micro- and macroelements in lichens show no significant anthropogenic impact. The elements are divided into two large groups according to their characteristic distribution among the lichen biomass fractions. In the first group, elements are firmly bound to lichen biomass through the mechanical capture of dust particles from atmospheric deposition. Elements from the second group are physicochemically affected by the lichen and are distributed to varying degrees throughout the lichen biomass fractions.