RADIOECOLOGICAL ASSESSMENT OF THE DISTRIBUTION OF NATURAL RADIONUCLIDES IN THE SOIL COVER OF THE NORTEASTERN REGION OF AZERBAIJAN

This article presents the results of studies on the distribution of natural radioisotopes in soil samples taken from northeastern region of Azerbaijan, their relationship with geochemical indicators and their radioecological assessment. The aim of the study was to determine the mechanisms of behavior of radionuclides in regions with different geological and lithological conditions and to assess the level of radiological safety of soils. Chemical analysis of soil samples shows that the content of sulfates, chlorides, Ca-carbonates, Na and K, as well as the ratio of Fe/Mn elements has significant variability across areas. These parameters are the main geochemical indicators, which directly affects the migration, sedimentation and immobilization level of radioisotopes in the soil. According to the table data, sulfates and Ca-carbonates are at the highest level in the Shabran region, which creates conditions for more stable retention of Sr isotopes in the immobile phase. The high level of chlorides in the Khizi district may cause Na²² and other radionuclides to move more actively in the form of ion complexes. The soil samples taken from Siyazan district exhibit more balanced amounts of Na, K, and Ca-carbonates, creating intermediate geochemical conditions. The concentrations of natural radionuclides (₁₁Na²², ₁₉K⁴⁰, ₃₈Sr⁹¹, and ₉₀Th²²⁸) correspond to background levels and no radiological dangerous concentrations were detected across all study sites. The conducted research confirms that the distribution of radionuclides in the soil is a multifactorial process, and geochemical parameters play a key role in maintaining their stability. The results of research show that the chemical content of soil samples taken from norteastern regions of Azerbaijan are safe from a ecological point of view and the current radionuclide levels do not pose a risk to the ecosystem. These results are reliable scientific basis for future stages of radioecological monitoring in the region.