Temporal variation of the pseudo total content of heavy metals in Ulaanbaatar soil

This work shows some of the results of investigation into pseudo total content of heavy metals in the surface soil of Ulaanbaatar.The main objectives of this study are to (i) evaluate temporal variability of pseudo-total content of Pb, Cu, Zn, Cd, Cr, Ni, Co and Mn in surface soil of Ulaanbaatar collected from 2003 to 2018, (ii) identify the main discriminates - metals during the years 2003-2018 years and, (iii) investigate the interdependence of main discriminates on the soil reaction (pH) and soil organic matter.Due to urbanization and negative human activities, surface soil in Ulaanbaatar losing their natural features, which are changing, while the spatial and temporal distribution of heavy metals in urban surface soil is becoming irregular. In Ulaanbaatar surface soil, the mean concentration of Cu, Zn and Pb much mois very high and the mean concentration of Co is lower than background soil. In some land use zones, it was found that the mean concentraion of Zn and Cr was considerably higher than the permissible level. The pollution condition of Mn, Zn, Cr, Ni and Cd was the same in 2010-2018 and the pollution conditions of Pb, Cu and Co are different. The main discriminants are Pb, Cu and Co. In Ulaanbaatar soil, a strikingly close correlationhip was established for Cu, Pb with the soil organic matter, and for Cd, Zn, Cr with the pH, respectively

Content and distribution of some chemical elements in the poplar leaves (Populus laurifolia) in Ulaanbaatar

In the last more than two decades, technogenic environmental pollution of Ulaanbaatar (Mongolia) has become a critical issue due to the rapid growth of the city’s population and environmental objects such as soil, plant and water in Ulaanbaatar territory have been heavily contaminated through air. The objectives of this study were (1) to determine the toxic and biophilic elements in the leaves of laurel poplar (Populus laurifolia) in Ulaanbaatar (Mongolia) and to study the behaviour and interdependence of its distribution, (2) and to assess the ecological state of laurel poplar (Populus laurifolia). In the leaves of laurel poplar (Populus laurifolia) on the territory of Ulaanbaatar, the distribution of most of the studied toxic and biophilic elements is even, but only Mg, Ca, and Mn are not evenly distributed. The biogeochemical feature of laurel poplar (Populus laurifolia) on the territory of Ulaanbaatar was studied by comparing it with the value of the world clarke and with the average content of elements in plant ash according to Alekseenko and with the background value. Our study revealed the accumulation of Zn, Ni, Cd, Pb and the scattering of Fe, Mn, Co, Cu in the leaves of laurel poplar (Populus laurifolia) in Ulaanbaatar In Populus laurifolia leaves in Ulaanbaatar area the median value of Fe/Mn ratio is 4.2-2.7 times, and the median value of Pb/Mn ratio is 6.7 times higher the normal and Cu/Zn ratio is at an equilibrium. The highest Fe/Mn ratios are found along the main highway (10.45) and in the city centre (11.09)