Returning settlements in radioactively contaminated territories to normal living conditions in 40 years after the Chernobyl NPP accident

Four decades after the Chernobyl accident, more than 1,500 settlements remain radioactively contam-inated (with 137Cs levels exceeding 37 kBq/m2), 72 of which have average annual exposures doses exceeding 1 mSv. This article examines the current challenges of returning settlements with elevated radiation levels to normal living conditions and explores possible solutions. It is shown that all settle-ments with average annual exposure doses exceeding 1 mSv (the city of Novozybkov and 71 rural settlements with a total population of 63,900) are located in five southwestern districts of the Bryansk region. The most critical dose-forming areas (population 26,000) are rural settlements, where up to 80% of local milk, beef, and wild mushroom samples currently fail to meet SanPiN requirements for 137Cs content. In these settlements, the contribution of 137Cs-contaminated milk from the private sector to the internal exposure dose of residents averages approximately 60%, mushrooms 20%, and potatoes and meat 10% each. The deterioration of the demographic situation and age structure of the population in recent decades, as well as changes in the diet of rural residents in the southwestern Bryansk region, must be taken into account when assessing internal exposure doses and their relationship with external radiation exposure. To reduce the exposure doses of residents of 71 rural settlements to below 1 mSv/year, a targeted rehabilitation strategy has been justified, incorporating the most effective technologies for reducing internal and external exposure of the population. An assessment of the radiological effectiveness of rehabilitation was conducted using GIS to support decision-making based on the costs of implementing technologies and stakeholder attitudes toward them. In addition to the radiation factor, the need to improve the demographic situation and develop the social infrastructure of populated areas to restore them to normal living conditions was noted.