The transboundary Irtysh River flows through the territory of three states: China, Kazakhstan and Russia.

Water quality of small rivers in the Ulba basin has been assessed in the impact zone of the mining industry of the Ridder region in East Kazakhstan.

This paper presents research data on water contamination levels of artificial radionuclides and heavy metals in Karabulak Creek at the Semipalatinsk Test Site. The uranium isotopic composition has been studied (²³⁵U and ²³⁸U). Priority contaminants and the most ‘contaminated’ sections of the Karabulak creek were identified, and water quality-related indicators were also estimated. The environmental situation around Karabulak Creek at the «Degelen» site—at which underground nuclear tests have been conducted—was found to be unique and attributed to the combined effect of man-made radiation and natural factors and, in particular, to geochemical features of the region.

The results of studying the features of the spatial distribution of macro- and microelements in the “water – bottom sediments” system in the channel of the Uzynbulak creek (“Degelen” site of the Semipalatinsk test site, Kazakhstan) are presented. The studies were carried out in the summer of 2015. As a result of the study of the chemical composition in surface waters and bottom sediments of the Uzynbulak creek, the content of Li, Be, Na, Mg, K, Ca, V, Ni, Mo, Fe, Sr, Al, Zn, Ba, La, Ce, U was revealed. The nature of the origin and the main factors determining the increased content of a number of the studied elements have been determined. The main mechanisms of the formation of the elemental composition in surface waters, the degree of spreading of elements exceeding the MPC (maximum permissible concentration) beyond the “Degelen” site are considered.

The relevance of this work is caused by the need to expand the methods of complex environmental studies to assess the quality of environmental objects in small communities. The study of the elemental composition of dust and aerosol depositions will provide the most complete picture of the quality status of the main natural components. Air aerosols are a complex dispersed system that includes particles smaller than 10 microns. These particles have both natural and man-made origin: finely dispersed dust particles of soil, plants, microorganisms, soot, ash, components of smoke emissions from boiler houses, industry, etc. Atmospheric air of small settlements remains poorly studied, there are no systematic data on the chemical composition of atmospheric pollutants, and therefore the relevance of this work is determined. The aim of the research is to determine the elemental composition of the solid phase of the snow cover of a small settlement Dolon. Objects: dust-aerosol deposition, particulate matter of air aerosols, snow cover, coal and ash. Techniques: mass spectrometric and atomic emission with inductively coupled plasma (MS-ISP, OES-ISP) Results. The elemental composition of snow melt water and solid phase of snow was studied. To determine the degree of volatility of chemical elements their coefficient of enrichment from coal to ash was calculated. The main zones with increased content of heavy metals in dust and aerosol depositions were determined. In the snow cover of the investigated territory a group of elements with high migratory capacity was revealed. Maps of the snow cover pollution of the Dolon settlement were constructed with identification of areas (halos of pollution) with increased content of the studied groups of elements.

Relevance of the research is caused by the necessity of obtaining up-to-date data on concentrations of chemical elements in the "water-soil-plant" system on the near-entry spot of tunnel 504 of "Degelen" site at the former Semipalatinsk Test Site. During flooding in spring, elements may be carried out beyond tunnel 504. The main aim of the research is to study spatial distribution of chemical elements in the "water-soil-plant" system in the streamflow of tunnel 504. To achieve this goal, the following tasks were set: 1) determine concentration levels of chemical elements in water; 2) study concentration levels of chemical elements in soil; 3) identify features of chemical elements accumulation in plants of tunnel 504. Methods. The ultimate composition of water was determined by inductively-coupled plasma mass-spectrometry (Elan 9000 "Perkin Elmer SCIEX"), inductively-coupled plasma atomic emission spectrometry ("iCAP 6300 Duo" Thermo Scientific). The analysis of such indicators as total mineralization, the content of sulfates, hydrocarbonates, chlorides, calcium, magnesium and sodium was carried out using titrimetric, colorimetric, potentiometric techniques in accordance with GOST. Results. The analysis of the data obtained for water showed a high content of such elements as Li, Be, Al, Mn, Zn, Rb, Sr, Cd, Cs, La, Ce, U the average content of which exceeds the clarke several times for groundwater of the arid climate (sulfate water). The excess of maximum permissible levels of such elements as Be (2800 MPC), Mn (260 MPC), Al (76 MPC), U (70 MPC) and Cd (50 MPC) has been registered for water. According to the latest data, the content of such elements as Li, Be, Al in water was found to increase by 2 times whereas that of Co, Ni and Cu - by dozens of times. Spatial distribution of elements of interest in soil of tunnel 504 is non-uniform. Most of elements are concentrated in soil to the north of the streamflow bed. An elevated content of such elements as Be, Mn, Cu, Zn, Mo, Cd, Cs, Pb and U was detected in this area exceeding the clarke of lithosphere. The high index of lithosphere clarke value excess was found for uranium concentration (1000 times). Comparison of findings for contaminated areas with values of maximum permissible concentrations of chemical elements in soil showed the excess for Pb (26 MPC), Mn and Cu (9 MPC). Chemical composition of water and soil of tunnel 504 is unique by the content of rare-earth elements. The average content of REE in water exceeds the clarke by thousand times in ground water of the arid climate and STS ground water. The excess of the maximum permissible concentration level of samarium was observed in water. Predominance of light REE is characteristic, with a pronounced cerium-lanthanum feature. This fact shows that metals in water originate from natural sources. For most plant species of tunnel 504 an elevated content of Be, Cd, Cs, Pb, U and a number of REE was detected in the contaminated area. Concentrations of elements of interest in such plant species as reed and bluejoint in areas being compared, varied insignificantly which is apparently attributed to some physiological and biochemical mechanisms that impede the intake. Based on the above, one can conclude that spatial distribution of elements at tunnel 504 is first of all related to chemical elements carried out by tunnel water. About ten elements exceeding clarke values and maximum permissible levels were detected in water of tunnel 504.