Radiation biology. Radioecology
ISSN: 0869-8031

Archives → 2023 → Vol. 63, № 2 → pp. 172–185

Article

Dynamics of ¹³⁷Cs Transfer Factors to Agricultural Products after the Chernobyl Accident: Grain, Potatoes, and Vegetables

S. V. Fesenko¹, P. V. Prudnikov², E. S. Emlyutina¹, I. E. Epifanova¹, I. E. Titov¹, O. A. Shubina¹

¹Russian Institute of Radiology and Agroecology, Obninsk, Russia ²Bryansk Center of Chemicalization and Agricultural Radiology,Bryansk Michurinskiy village, Bryansk region, Russia

Abstract

The results of the analysis of the 137Cs aggregated transfer factors (Tag) to crops (cereals, potatoes, and vegetables) produced in the districts of the Bryansk region affected after the Chernobyl accident are presented. The aggregated transfer factors in the year of the deposition as well as the dynamics of Tag in the subsequent years depended considerably on the fertility of soils subjected to contamination. The transfer factors of 137Cs to crops in the areas with higher fertility were 3–8 times lower (depending on the plant species) than in the areas with low fertility, and the most significant differences were observed for cereals. Decrease in Tag values was of irregular nature. The half-lives of 137Cs aggregated transfer factors for the period from 1986 to 2021 were calculated. It is shown that the first half-life values calculated for the period of intensive application of countermeasures (1987–1991) were from 0.7 to 1.4 years. The second half-lives varied from 7.3 to 17.3 years. In some areas, after a strong reduction in 137Cs concentrations in crops after 1994, there was a slow increase in 137Cs aggregated transfer factors, which can be explained by insufficient compensation for this decrease of geochemical binding of 137Cs in the soil. Later the dynamics of crop contamination was determined by multidirectional processes: i.e., increase in 137Cs transfer to plants and natural decrease of radionuclides bioavailability in soils under the influence of geochemical processes. In areas with intensive application of countermeasures, the reduction of Tag to crops was determined to a greater extent by the influence of agrochemical countermeasures. In the areas with limited application of countermeasures, the natural biogeochemical processes determining radionuclide binding by the soil-absorbing complex made the predominant contribution to the Tag reduction. Limitations of the approach based on the estimation of half-lives and the necessity of using the history of countermeasures implemented, as well as the soil fertility for prediction of the 137Cs intake by plants is noted.

Keywords

Chernobyl NPP, transfer factor, agricultural products, south-western districts of Bryansk region, monitoring in agriculture, ¹³⁷Cs