Contribution of foodstuffs contained radionuclides to formation of internal radiation doses received in areas Bryansk region affected by the Chernobyl accident

The authors review current specific features of internal radiation doses received by people resided in 135 urban and rural settlements in six south-western districts of the Bryansk region affected by the Chernobyl accident. The residents received the average annual radiation dose > 1 mSv. The Cs-137 radioactivity contained in local agricultural and natural food was evaluated with the account of the dietary structure. Comparative analysis of long-term data on a contribution of local food contained radionuclides to the population, estimated by the average annual effective dose of internal radiation was carried out. Potatoes and pork taken from the private farms in the settlements under survey met health and hygiene standards for different levels of Cs-137 in 2022. However, there was a risk of exceeding the sanitary hygiene’s requirements for Cs-137 specific radioactivity in milk from privately-owned farms located in 89% of the settlements under survey, in 98% of beef produced in the farms and in 100% of mushrooms collected in forests near these settlements. Currently, the main dose-forming product is milk (contribution to the internal exposure dose is 60%), a smaller role in dose formation is in mushrooms (about 20%) and a minimal dose is in potatoes and meat (10% each). Over the past 20 years, the contribution of milk to the internal exposure dose has increased by 15-20%, and the contribution of mushrooms has decreased because of changes in the diet of the rural population of the Bryansk region and due to the reduction and redistribution of local products in the food basket.