Cesium-137 stored on and discharged from banks of an agricultural canal in Iitate, Fukushima. (January 2022)

• Record Type: Journal Article
• Authors: Tajima, Satoshi; Yoshida, Shuichiro; Fukui, Taku; Nihei, Naoto; Kobayashi, Natsuko I.
• Is Part Of: Journal of environmental radioactivity. Volume 241(2022)
• Publication Date: 2022-01
• Subjects: Fukushima Daiichi nuclear power plant -- Radiocesium -- Cesium-137 -- Sequential extraction -- Litter; Radioactivity -- Periodicals; Radiation, Background -- Periodicals; Radioecology -- Periodicals; Radioactive pollution -- Periodicals; Environmental Pollutants -- Periodicals; Radioactive Pollutants -- Periodicals; Radioactivity -- Periodicals; Radioécologie -- Périodiques; Pollution radioactive -- Périodiques; Fond de rayonnement -- Périodiques; 539.752
• DOI: 10.1016/j.jenvrad.2021.106775
• Languages: English
• ISSNs: 0265-931X

Abstract

Abstract: This study aimed to investigate the dynamics of 137 Cs around banks along an agricultural canal for paddy fields in Iitate, Fukushima, Japan. Five plots (2.4–12.6 m 2 ) on the banks were monitored intermittently during six time periods from May 2018 to November 2019. We directly collected runoff water samples discharged from the banks followed by partitioning it into particulate and dissolved fractions and determining 137 Cs in them. To investigate the source of 137 Cs in the runoff water, we sequentially extracted 137 Cs in various chemical forms from litter samples collected on the banks. The results showed that the discharge rates of the dissolved 137 Cs per unit area from the plots were lower than those observed at the downstream of the agricultural canal, whereas more than 50% of the 137 Cs discharged from the plots was in the dissolved fraction. Moreover, the results indicate that 137 Cs stored in the standing plants and the litter was the primary source of the dissolved 137 Cs discharged into the agricultural canal. The concentrations of the water-soluble 137 Cs in the litter per plot area may have been retained by the sufficiently higher concentrations of 137 Cs in litter in other chemical forms and those in the standing plants, which are the source of the litter. Highlights: Dissolved 137 Cs accounted for more than 50% of the total 137 Cs discharged. Sufficient 137 Cs is stored in plants and litter in various chemical forms. Cesium-137 stored in plants and litter can supply the discharged dissolved 137 Cs.