Medical Radiology and Radiation Safety. 2014. Vol. 59. No. 5. P. 5-13
RADIATION SAFETY
A.V. Panov, V.V. Ponomarenko, E.V. Marochkina
Variations in the Role of Radionuclide Containing Foodstuffs in Dose Formation from Internal Irradiation of the Population in Different Periods after the Chernobyl NPP Accident
Russian Institute of Agricultural Radiology and Agroecology of RAAS, Obninsk, Russia. E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
ABSTRACT
Purpose: Estimation of regularities of variations in the contribution of the main dose-forming foodstuffs contaminated by radionuclides to the dose formation from internal irradiation of the population in the Chernobyl affected area 20 years after the accident and analysis of factors responsible for dose formation in humans.
Material and methods: A study was performed in the two regions of Russia most affected after the Chernobyl accident. In the both regions rural settlements were investigated Krasnogorsk district in the Bryansk region and Plavsk district in the Tula region. These are distinguished in both levels of 137Cs contamination and soil properties. For the settlements of studied areas, module calculations of level 137Cs contamination of agricultural and natural food products, consumed by the residents after the Chernobyl accident, from 1990 to 2010 are executed. The dynamics of 137Cs contamination of food products, as well as dose to the residents from internal exposure during 20 years after the accident without application of countermeasures were evaluated.
Results: Based on the obtained of modular data, changes in the radioecological situation in the affected rural settlements were analyzed. Regularities were described of 137Cs contamination of farm and natural food products, as well as peculiar features of dose formation from internal exposure in various periods after the Chernobyl accident. The estimates took into account radioecological, regulatory and time factors.
Conclusion: Based on the model calculations, significant variations in time of the ratio contribution of agricultural and natural foods in the internal dose of the population in different soil types are shown. Thus, 4 years after the accident, on light (sandy, light and medium-loam) soils the main contributor to the internal dose to the population was agricultural produce — 65 % (milk — 35 %), mushrooms — 35 %. By 2000, the contribution of the mushroom component increased to 50 %. On heavy (clay) soils, in 1990, the contribution of farm products to internal exposure of the residents amounted to 80 % (milk — 45 %). To date, the contribution to the internal dose of mushrooms on these soils grew to 30 %. These features are explained by different rate of decline with years of 137Cs transfer factors from light and heavy soils to agricultural and natural food products.
Key words: Chernobyl accident, internal exposure doses, specific radionuclide activity in foodstuffs, 7Cs transfer factor