COMPREHENSIVE RADIATION AND HYGIENIC MONITORING IN POPULATION OF THE RIVNE OBLAST RADIOLOGICALLY CONTAMINATED TERRITORIES

Abstract

Objective. The key factors identification in radiation dose formation in population of radiologically contaminated areas of Rivne oblast in the current period of accident through comprehensive radiation and hygienic monitoring in reference settlements in 2020 and estimation of their impact on dose formation were the study objectives. Materials and methods. Comprehensive radiation and hygienic monitoring of settlements in Rivne oblast (province) was provided in Stare Selo, Vezhytsia, Perekhodychi, and Drozdyn villages of Rokytne district, where the highest radiation doses were registered after the ChNPP accident. Studies were conducted in September 2020. Measurements (n=696, 318 adults, and 378 children) were performed using the whole body counters (WBC) to determine the internal radiation doses. The 48 samples of milk, 45 samples of potatoes and vegetables, and 35 samples of wild products were collected in local farms and measured for the 137Cs and 90Sr content. Residents of the studied settlements (n=229, 140 adults, and 89 children) were interviewed about the levels of consumption of staple foodstuffs. External radiation doses were evaluated in all the studied settlements. Mathematical, dosimetric, and radiochemical methods were applied. Results and conclusions. Annual effective radiation doses of the Rivne oblast population in 2020 were formed mainly due to internal radiation ones that not exceeded 1.24 mSv · year-1 in adults and 0.65 mSv · year-1 in children against the RCT criterion of 1 mSv · year-1. Further 1.2–1.9-fold decrease in the annual internal radiation doses vs. the results of WBC-monitoring in autumn of 2017 was registered in the surveyed settlements. The latter confirmed a time pattern of radiation levels gradual reduction at the current stage of Chornobyl accident since 2011. Intake of 137Cs with milk and wild mushrooms, which traditionally occupy a significant part of diet in the Rivne Polissya area and have consistently high levels of radioactive cesium contamination, remains a key factor of internal radiation dose forming in residents of the surveyed settlements of Rivne oblast. The Scientific Council meeting of NAMS approved the NRCRM Annual Report. Key words: radiologically contaminated territories, comprehensive radiation and hygienic monitoring, internal radiation dose, whole body counter, 137Cs and 90Sr content, food.