Transfer of 137Cs and 90Sr from soil-to-potato: Interpretation of the association from global fallout in Aomori to accidental release in Fukushima and Chornobyl

Hirofumi Tsukada; Akira Takeda; Tomoyuki Takahashi; Satoshi Fukutani; Makoto Akashi; Junko Takahashi; Shinichiro Uematsu; Ihor Chyzhevskyi; Serhii Kirieiev; Valery Kashparov; Mark Zheleznyak

doi:10.1016/j.scitotenv.2023.165467

Transfer of ¹³⁷Cs and ⁹⁰Sr from soil-to-potato: Interpretation of the association from global fallout in Aomori to accidental release in Fukushima and Chornobyl

Sci Total Environ. 2023 Nov 15:899:165467. doi: 10.1016/j.scitotenv.2023.165467. Epub 2023 Jul 15.

Authors

Affiliations

¹ Institute of Environmental Radioactivity, Fukushima University, 1 Kanayagawa, Fukushima-shi, Fukushima 960-1296, Japan. Electronic address: hirot@ipc.fukushima-u.ac.jp.
² Department of Radioecology, Institute for Environmental Sciences, 1-7 Ienomae, Obuchi, Rokkasho, Kamikita, Aomori 039-3212, Japan.
³ Institute for Integrated Radiation Nuclear Science, Kyoto University, 2 Asashiro-Nishi, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan.
⁴ Tokyo Healthcare University, 2-5-1 Higashigaoka, Meguro-ku, Tokyo 152-8558, Japan.
⁵ Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan.
⁶ State Specialized Enterprise "Ecocentre" of the State Agency of Ukraine on Exclusion Zone Management, 6, Shkilna Str., Chornobyl, Kyiv Region 07270, Ukraine.
⁷ Ukrainian Institute of Agricultural Radiology of the National University of Life and Environmental Sciences of Ukraine, Mashinobudivnykiv str. 7, Chabany, Kyiv Region 08162, Ukraine.
⁸ Institute of Environmental Radioactivity, Fukushima University, 1 Kanayagawa, Fukushima-shi, Fukushima 960-1296, Japan.

PMID: 37454838
DOI: 10.1016/j.scitotenv.2023.165467

Abstract

Ceasium-137 and ⁹⁰Sr are major artificial radionuclides that have been released into the environment. Soil-to-plant transfer of radionuclides is an important route to food contamination. The radionuclide activity concentrations in crops must be quantitatively predicted for estimating the internal radiation doses from food ingestion. In this study, soil and potato samples were collected from three study sites contaminated with different sources of ¹³⁷Cs and ⁹⁰Sr: Aomori Prefecture (global fallout) and two accidental release areas (Fukushima Prefecture and the Chornobyl exclusion zone). The ¹³⁷Cs activity concentrations in the soil and potato samples widely ranged from 1.0 to 250,000 and from 0.048 to 200,000 Bq kg^-1 dry weight, respectively. The soil-to-potato transfer factor of ¹³⁷Cs also ranged widely (0.0015-1.1) and decreased with increasing concentration of exchangeable K. Meanwhile, the activity concentrations of ⁹⁰Sr in the soil and potato samples were 0.50-64,000 and 0.027-18,000 Bq kg^-1 dry weight respectively, and the soil-to-potato transfer factor of ⁹⁰Sr was 0.023-0.74, decreasing with increasing concentration of exchangeable Ca. The specific activity ratios of ¹³⁷Cs/Cs and ⁹⁰Sr/Sr in the exchangeable fraction were similar to those in potatoes, with a factor of 3 in the ±95 % confidence intervals over six orders of magnitude and a factor of 2 in the ±95 % confidence intervals over five orders of magnitude, respectively. According to the data, the accuracy of predicting the activity concentrations of ¹³⁷Cs and ⁹⁰Sr in potatoes can be improved by applying the specific activity ratios of ¹³⁷Cs/Cs and ⁹⁰Sr/Sr in the exchangeable fraction. This approach accounts for variable factors such as the effects of K and Ca fertilization and soil characteristics. It also emphasizes the benefit of determining the stable Cs and Sr concentrations in potatoes and other crops prior to possible future contamination.

Keywords: (137)Cs/Cs; (90)Sr/Sr; Accidental release; Exchangeable fraction; Global fallout; Soil-to-plant transfer; Specific activity ratio.

MeSH terms

Cesium Radioisotopes / analysis
Chernobyl Nuclear Accident*
Fukushima Nuclear Accident*
Radiation Monitoring*
Soil
Soil Pollutants, Radioactive* / analysis
Solanum tuberosum*
Transfer Factor

Substances

Cesium-137
Strontium-90
Soil
Transfer Factor
Soil Pollutants, Radioactive
Cesium Radioisotopes