Abstract
<jats:p>Background. The Chornobyl accident caused long-term radioactive contamination of the environment and became a source of significant radiation exposure doses to the population of Ukraine. Over 40 years, a unique experience of systematic monitoring and research has been accumulated, which is of exceptional importance for assessing current radiation risks, improving the national radiation protection system, and integrating Ukrainian achievements into international nuclear safety standards. Purpose – to summarize 40 years of Ukrainian experience in the field of studying radioactive contamination of the environment and dose exposure of the population after the Chornobyl accident. Materials and Methods. The study was based on data from long-term ecological and dosimetric monitoring conducted in Ukraine since 1986. The levels of radioactive contamination of the environment (137Cs, 90Sr, 238,239,240Pu) and the radiation doses of the population were assessed. All results are systematized in the Central Ecological and Dosimetric Register (CEDR), which includes administrative-territorial, ecological and dosimetric blocks. Results. The obtained data indicate that the soil is the main long-term source of radionuclides of Chornobyl origin, and the dynamics of the activity of 137Cs and 90Sr reflects the processes of physical decay and migration, which led to a gradual decrease in contamination levels, but preserved their territorial heterogeneity. It was established that contamination of food products does not always directly correlate with the density of precipitation on the soil, which is explained by its agrochemical characteristics. Internal exposure of the population was most significant in the first years after the accident, with a subsequent decrease and stabilization at a low level. An important result was the system of dosimetric certification, which performed a regulatory function and ensured social protection of victims. Conclusions. The results of a forty-year study show the transition from the phase of acute radiation exposure to the stage of long-term controlled monitoring. The key factors in the formation of current dose levels remain the properties of soils, the specifics of local agricultural production and socio-economic living conditions. The accumulated data has a strategic importance for improving the national radiation protection system, harmonizing dose assessment methods and integrating Ukrainian experience with world standards in the field of nuclear accident consequences management.</jats:p>