ASSESSMENT OF CHEMICAL ELEMENT CONTENT IN THE NATURAL ENVIRONMENT COMPONENTS OF THE «VOSTOCHNY» TRACE OF THE RADIOACTIVE FALLOUT AT THE SEMIPALATINSK TEST SITE

Relevance of this work is attributed to the fact that no activities were carried out to assess the content of the chemical composition in environmental components including heavy metals and toxicants along the «Vostochny» fallout plume identified by the radioecological survey of areas adjacent to the Semipalatinsk Test Site. A concurrent survey of air aerosol particulate matter and soil composition at the «Opytnoe pole» site, at which atmospheric/aboveground-air nuclear tests were conducted, will provide a complete picture on potential sources of a radionuclide and chemical composition of environmental components formed in the «Vostochny» trace as well as of migration pathways of some elements and radionuclides incorporated in air aerosols. The survey of the north-eastern test site part, along the passing fallout trace, including settlements with agricultural activities, is especially topical to the population living there. The objective of this paper is to evaluate accumulation levels of radionuclides and chemical elements in soil cover of the impact zone of the «Vostochny» trace at the Semipalatinsk Test Site as well as to reveal a possible input of certain chemical elements and radionuclides from the Semipalatinsk Test Site territory to adjacent areas along the «Vostochny» plume profile. Objects: soil, air aerosol particulate matter. Techniques. Samples were analyzed by alpha-, beta- and gamma-spectrometry, inductively coupled plasma mass-spectrometry, inductively coupled plasma atomic-emission spectrometry, by radiochemistry and scanning electronic microscopy; statistical processing of analytical results on the main environmental components of interest; assessment of the dynamics of spatial distribution of the content of radionuclides and chemical elements in samples of soil and air aerosol particulate matter in the study area. Results. Chemical compositions (radionuclide and elemental) of soil cover in the profile of the «Vostochny» trace and 2,5 µm air aerosol particulate matter and total suspended particles, collected from areas located close to boundaries of the Semipalatinsk Test Site «Opytnoe pole» site, were studied. A spatial distribution of concentrations of chemical element groups under study and radionuclides in soil cover was identified in the «Vostochny» fallout trace. The correlation analysis of the content of elements in air samples allowed identification of associations of elements being characteristic of both fine particles (PM-2,5) and total suspended air particles at the Semipalatinsk Test Site «Opytnoe pole» testing site. The content of almost all chemical elements of interest incorporated in air aerosol particulate matter does not exceed permissible levels – maximum permissible concentrations.