Keywords: radiation and environmental monitoring, radiation state of environmental components, exclusion zone

The article presents results of radiation and environmental monitoring in the Exclusion Zone for the year 2025. According to the results of radiation and environmental monitoring in the Exclusion Zone in 2025, important analytical data were obtained: - Maximum power values of the ambient dose equivalent of gamma radiation are characteristic of the territories in the northern and western 'traces' of radioactive fallout; - Radiation state of the Exclusion Zone air environment and its dynamics during 2025 were determined by the nature of surface contamination of the territory, сontrol levels exceeding activity in the air was recorded; - Surface waters remain an important route of radionuclide removal beyond the Exclusion Zone; - Radiation state of underground waters, radionuclide contamination of eocene and cenomanian-lower cretaceous water-bearing complexes; - Monitoring results at landscape landfills; - Radiation survey results of unauthorized residence places of the population in the Exclusion Zone. Compared to 2024, the average annual value of the volumetric activity of 137Cs and 90Sr in the surface layer of the atmosphere of the Chernobyl Nuclear Power Plant remained approximately at the same level or slightly decreased. In 2025, the discharge of 90Sr from the Pripyat River in the Chernobyl zone was 3.2 times less than in 2024 and 2.5 times less than the average value of the last 5 years. The inflow of 90Sr from outside the exclusion zone did not exceed 32% of the total discharge from the Pripyat River. The content of 90Sr was recorded in all observation wells. The maximum values of the volumetric activity of 90Sr in the waters of the Quaternary aquifer complex were recorded in the areas of the old Budbaza, Lake Azbuchyn, and Yanivskyi Zaton, and were 140, 66, and 57 Bq/dm3.

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