Ulaanbaatar surface soils are subject to high anthropogenic pressure. Sources of potentially toxic elements (Ag, As, B, Ba, Bi, Co, Cd, Cr, Cu, F, Ge, Mo, Mn, Li, Ni, Pb, Sb, Sn, Sr, Tl, V and Zn) in the surface soil were identified by factor analysis via the trace element composition of 325 soil samples. The samples characterized the different areas of the city and had different degree of anthropogenic load: near thermal power plants; roads; residential areas; urban park zones. An exploration statistical analysis of the data showed that there was one (or more) pollution source. Factor analysis identified five principal components to explain 69,1 % of the total data variance. Ordinary kriging was used to interpolate and map of soil properties. The distributions of the selected factors indicate a high probability of environmental problems for the areas of Ulaanbaatar where thermal power plants and yurt buildings are located, and also point that dust aerosols from coal combustion is the main reason the enrichment of urban soils with trace elements. The specific wind rose contaminates the Central area of Ulaanbaatar by coal combustion products in the Northern areas of the yurt building and TPP-3, located in the West of the city. It is shown that a complete description of the sources of the type of contamination of surface soils of Ulaanbaatar, as well as the development of the most appropriate methodology of corrective actions, require the expansion of the statistical model data of the trace element compositions of the studied soils. The study was conducted in the framework of joint research between the Vinogradov Institute of Geochemistry SB RAS, Institute of physics and technology MAN and Irkutsk state University.

Tsagaan Byambasuren, Postgraduate, Reseacher, Irkutsk State University, 1, K. Marx st., Irkutsk, 664003, Russian Federation, tel.: + 7 (3952) 24-32-80, Institute of Physics and Technology of MAS, 54b, Peace av., Ulaanbaatar, 13330, Mongolia, tel.: +(976) 11 452313, e-mail: tsagaanbyambasuren@gmail.com 

Shabanova Elena Vladimirovna, Doctor of Sciences (Physics and Mathematics), Senior Researcher, Vinogradov Institute of Geochemistry SB RAS, 1а, Favorsky st., Irkutsk, 664033, Russian Federation, tel.: + 7 (3952) 425837, e-mail: shev@igc.irk.ru 

Korolkov Alexei Tikhonovich, Doctor of Sciences (Geology and Mineralogy), Professor, Irkutsk State University, 1, K. Marx st., Irkutsk, 664003, Russian Federation, tel.: + 7 (3952) 24-32-80, e-mail: baley51@mail.ru 

Vasilyeva Irina Evgenyevna, Doctor of Sciences (Engineering), Chief Scientist, Vinogradov Institute of Geochemistry SB RAS, 1а, Favorsky st., Irkutsk, 664033, Russian Federation, tel.: + 7 (3952) 425837, e-mail: vasira@igc.irk.ru 

Ganbaatar Ochirbat, Master, Institute of Physics and Technology of MAS, 54b, Peace av., Ulaanbaatar, 13330, Mongolia, tel.: +(976) 11 452313, email: ochir_0528@yahoo.com 

Byambaa Khuukhenkhuu, Candidate of Physical and Mathematical, Professor, Senior Research, Scientist Institute of Physics and Technology of MAS, 54b, Peace av., Ulaanbaatar, 13330, Mongolia, tel.: +(976) 11 452313, email: hunstech@yahoo.co.uk

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