The deposition and vertical depth distribution of 134Cs and 137Cs in the natural undisturbed soil profiles down to 20-25 cm were studied at locations in the North Eastern Estonia, which were most strongly affected by the Chernobyl fallout in 1986. The total depositions were estimated based on summing the sampled and measured activities of 134Cs and 137Cs in all sections of soil profiles. The Chernobyl 137Cs deposition values varied considerably from site to site and the range was from 3.9 kBq m(-2) to 50.2 kBq m(-2), with the average of 22.8 kBq m(-2) for the region (reference data May 1, 1986). The ratio of total activities, A(134Cs)/A(137Cs), varied in the range from 0.47 to 0.55. Using a compartment model and the observed data on the 134Cs and 137Cs activity concentrations (Bq m(-2)) in four compartments, 0-1 cm, 1-5 cm, 5-15 cm and 15-30 cm, of soil collected in 1991-2003, the approximate residence half-times of radiocaesium in soil were determined. The latter increased from 3.7 y in the top-most compartment to 8.6 y and 36.4 y in the deeper compartments, respectively. The time dependence of the external gamma-dose rate at the height of 1 m above a flat ground area arising from the deposited and migrating radiocaesium was calculated using the modeled data on the 134Cs and 137Cs activity in soil compartments. Considering the total depositions of radiocaesium in soil from the Chernobyl 1986 accident, the 50 year effective doses caused by external gamma exposure varied in the range from 0.13 mSv to 1.74 mSv, with the mean of 0.79 mSv in the region.
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http://dx.doi.org/10.1016/j.jenvrad.2012.05.021 | DOI Listing |
Sci Total Environ
January 2025
Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway.
The presence of the long-lived radionuclides Cs and Sr in ecosystems is a major environmental concern because bioavailable forms of the radionuclides are readily transferred to living organisms. The present study investigated how holometabolous insect development influences the fate of radiocaesium and radiostrontium by examining the behaviour of tracers (Cs and Sr) and stable elements during the larval feeding stage (21-23 days old), the pupal stage, and the adult stage. We aimed to evaluate the degree to which an herbivore or a detritivore food chain could serve as transfer pathways to higher trophic levels in terms of accumulation potential, and during which stage of development the accumulation potential is highest.
View Article and Find Full Text PDFJ Environ Radioact
January 2025
Hama Agricultural Regeneration Research Centre, Fukushima Agricultural Technology Center, Minami-soma, Fukushima, 975-0036, Japan.
Radioactive cesium released into the atmosphere caused by the Fukushima Dai-ichi Nuclear Power Plant accident in March 2011 has contaminated the surrounding area. We confirmed the applicability of in-situ methods to evaluate the depth distribution of Cs by employing the ratio of Compton-scattering and photo-peak components (r) obtained from measured gamma-ray spectra. In the present study, we applied the in-situ method to farmlands in Fukushima Prefecture whose sites were disturbed by decontamination and plowing operations.
View Article and Find Full Text PDFProbl Radiac Med Radiobiol
December 2024
Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, 9609 Medical Center Drive, Bethesda, MD 20892, USA.
Objective: Scientific justification of the methodology for calculating radiation internal doses from 137Cs and 134Cs intake for residents of Ukrainian settlements radioactively contaminated as a result of the Chornobyl (Chernobyl) accident in which measurements of incorporated radiocesium isotopes in humans using whole-body counters (WBC) were not carried out.
Materials And Methods: The paper presents a new methodology for reconstructing doses due to internal irradiation from Chornobyl fallout for both surface (in 1986) and root (in 1987-2023) contamination of vegetation with 137Cs and 134Cs and their transfer into the human body. The methodology for calculating the dose due to surface contamination of vegetation was based on the theoretical model of the transfer of radiocesium isotopes through the food chain with further adjustment of this model to the results of WBC measurements carried out between 15 July and 31 December 1986.
J Environ Radioact
December 2024
Cooperative Division of Veterinary Sciences, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan; Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan. Electronic address:
Radiat Prot Dosimetry
November 2024
Institute of Radiation Emergency Medicine, Hirosaki University, Hirosaki, Aomori 036-8564, Japan.
The concentration of the radioactive cesium (134Cs and 137Cs) in soils and in atmospheric fallouts has been measured at the Koriyama campus, Nihon University, after the Fukushima Dai-ichi Nuclear Power Plant accident for 13 y, from October 2011 till September 2023 and now ongoing. The concentration of them decreased very rapidly due to decontamination activities and weathering effects, with an environmental half-life of 1.21 and 2.
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