A new approach for reconstructing the 131I-spreading due to the 2011 Fukushima nuclear accident by means of measuring 129I in airborne particulate matter. (November 2019)

• Record Type: Journal Article
• Authors: Ebihara, Mitsuru; Oura, Yasuji; Shirai, Naoki; Nagakawa, Yoshiyasu; Sakurai, Nomoru; Haba, Hiromitsu; Matsuzaki, Hiroyuki; Tsuruta, Haruo; Moriguchi, Yuichi
• Is Part Of: Journal of environmental radioactivity. Volume 208/209(2019)
• Publication Date: 2019-11
• Subjects: 129I -- 131I -- Fukushima nuclear accident -- Airborne particulate matter; 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.2019.106000
• Languages: English
• ISSNs: 0265-931X

Abstract

Abstract: To retrieve the diffusion trajectory of the 131 I dispersed in the environment by the nuclear power plant accident in Fukushima in 2011, airborne particulate matter (APM) samples collected in the Tokyo metropolitan area were analyzed for their 129 I contents by means of accelerator mass spectrometry. In evaluating blank levels of chemicals and filters used for collecting APM, we established the analytical procedure for determining the 129 I activity of as low as 10 −8 Bq for a small piece of filter samples (about 0.1 cm 2 ). Coupled with 131 I data determined just after the accident, activity ratios of 129 I/ 131 I were obtained with a mean value of 2.29 × 10 −8 (±28% of a standard deviation). This value is systematically smaller than a mean value of soil samples by 16–24% and the inventory data by 27%, suggesting that 129 I was partly lost from APM. As 129 I can be a proxy of 131 I for APM, it is possible to trace how 131 I in the particulate phase spread in eastern Japan and, furthermore, evaluate the internal radiation exposure due to 131 I by inhalation of 131 I-containing airborne particulates. Highlights: 10 −8 Bq of 129 I can be quantified for aerogel on 0.1 cm 2 filter paper. 129 I/ 131 I activity ratios for aerosol from the Fukushima nuclear accident determined. 129 I can be a proxy of 131 I for reproducing the diffusion trajectory of 131 I.