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Changes of absorbed dose rate in air in metropolitan Tokyo relating to radiocesium released from the Fukushima Daiichi Nuclear Power Plant accident: Results of a five-year study


Autoři: Kazumasa Inoue aff001;  Hiroshi Tsuruoka aff001;  Hideo Shimizu aff001;  Moeko Arai aff001;  Nimelan Veerasamy aff001;  Mizuho Tsukada aff001;  Ken Ichimura aff001;  Shuto Nakazawa aff001;  Yoshiaki Taguchi aff001;  Masahiro Fukushi aff001
Působiště autorů: Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Arakawa-ku, Tokyo, Japan aff001;  Department of Radiological Sciences, Tsukuba International University, Tsuchiura, Ibaraki, Japan aff002
Vyšlo v časopise: PLoS ONE 14(10)
Kategorie: Research Article
prolekare.web.journal.doi_sk: https://doi.org/10.1371/journal.pone.0224449

Souhrn

Car-borne surveys were carried out in metropolitan Tokyo, Japan, in 2015, 2016, 2017 and 2018 to estimate the transition of absorbed dose rate in air from the Fukushima Daiichi Nuclear Power Plant accident. Additionally, the future transition of absorbed dose rates in air based on this five-year study and including previously reported measurements done in 2014 by the authors was analyzed because central Tokyo has large areas covered with asphalt and concrete. The average absorbed dose rate in air (range) in the whole area of Tokyo measured in 2018 was 59 ± 9 nGy h-1 (28–105 nGy h-1), and it was slightly decreased compared to the previously reported value measured in 2011 (61 nGy h-1; 30–200 nGy h-1). In the detailed dose rate distribution map, while areas of higher dose rates exceeding 70 nGy h-1 had been observed on the eastern and western ends of Tokyo after 2014, the dose rates in these areas have decreased yearly. Especially, the decreasing dose rate from radiocesium (Cs-134 + Cs-137) in the eastern end of Tokyo which is mainly covered by asphalt was higher than that measured in the western end which is mainly covered by forest. The percent reductions for the eastern end in the years 2014–2015, 2015–2016, 2016–2017 and 2017–2018 were 49%, 21%, 18% and 16%, and those percent reductions for western end were 26%, 18%, 6% and 3%, respectively. Additionally, the decrease for dose rate from radiocesium depended on the types of asphalt, and that on porous asphalt was larger than the decrease on standard asphalt.

Klíčová slova:

Surveys – Islands – Urban areas – Pacific Ocean – Dosimetry – Dust – Nuclear power – Porous materials


Zdroje

1. Saito K, Tanihata I, Fujiwara M, Saito T, Shimoura S, Otsuka T, et al. Detailed deposition density maps constructed by large-scale soil sampling for gamma-ray emitting radioactive nuclides from the Fukushima Dai-ichi Nuclear Power Plant accident. J Environ Radioact. 2015;139:308–19. doi: 10.1016/j.jenvrad.2014.02.014 24703526

2. United Nations Scientific Committee on the Effects of Atomic Radiation. Developments since the 2013 UNSCEAR Report on the levels and effects of radiation exposure due to the nuclear accident following the great east-Japan earthquake and tsunami, A 2017 White Paper to guide the Scientific Committee's future programme of work. 2017.

3. Kinoshita N, Sueki K, Sasa K, Kitagawa J, Ikarashi S, Nishimura T, et al. Assessment of individual radionuclide distributions from the Fukushima nuclear accident covering central-east Japan. P Natl Acad Sci USA. 2011;108(49):19526–9. doi: 10.1073/pnas.1111724108 22084070

4. Morino Y, Ohara T, Nishizawa M. Atmospheric behavior, deposition, and budget of radioactive materials from the Fukushima Daiichi nuclear power plant in March 2011. Geophysical Research Letters. 2011;38(7):L00G11. doi: 10.1029/2011GL048689

5. Inoue K, Tsuruoka H, Van Le T, Arai M, Saito K, Fukushi M. Impact on ambient dose rate in metropolitan Tokyo from the Fukushima Daiichi Nuclear Power Plant accident. J Environ Radioact. 2016;158–159:1–8. doi: 10.1016/j.jenvrad.2016.03.022 27055250

6. Inoue K, Hosoda M, Fukushi M, Furukawa M, Tokonami S. Absorbed dose rate in air in metropolitan Tokyo before the Fukushima Daiichi Nuclear Power Plant accident. Radiat Prot Dosimetry. 2015;(1–3):231–4. doi: 10.1093/rpd/ncv251 25944962

7. Inoue K, Hosoda M, Shiroma Y, Furukawa M, Fukushi M, Iwaoka K, et al. Changes of ambient gamma-ray dose rate in Katsushika Ward, metropolitan Tokyo before and after the Fukushima Daiichi Nuclear Power Plant accident. J Radioanal Nucl Chem. 2015;303(3):2159–63. doi: 10.1007/s10967-014-3669-x

8. Nuclear Regulation Authority. Extension site of distribution map of radiation dose, etc. 2011. Available from: http://radioactivity.nsr.go.jp/en/. Accessed 25 June 2019.

9. Andersson I, Lönsjö H, Rosén K. Long-term studies on transfer of 137Cs from soil to vegetation and to grazing lambs in a mountain area in Northern Sweden. J Environ Radioact. 2001;52(1):45–66. doi: 10.1016/S0265-931X(00)00102-8 11202685

10. Pröhl G, Ehlken S, Fiedler I, Kirchner G, Klemt E, Zibold G. Ecological half-lives of 90Sr and 137Cs in terrestrial and aquatic ecosystems. J Environ Radioact. 2006;91(1):41–72. doi: 10.1016/j.jenvrad.2006.08.004 17007973

11. Maedera F, Inoue K, Sugino M, Sano R, Furue M, Shimizu H, et al. Natural Variation of Ambient Dose Rate in the Air of Izu-Oshima Island after the Fukushima Daiichi Nuclear Power Plant Accident. Radiat Prot Dosimetry. 2006;168(4):561–565. doi: 10.1093/rpd/ncv370 26246583

12. Isaksson M, Erlandsson B, Mattsson S. A 10-year study of the 137Cs distribution in soil and a comparison of Cs soil inventory with precipitation-determined deposition. J Environ Radioact. 2001;55(1):47–59. doi: 10.1016/S0265-931X(00)00186-7 11381552

13. Saegusa J, Yoda T, Murakami M, Takeishi M. Analysis of ambient-dose-rate trends in Fukushima Ecological half-life, effect of snow covering. Kankyo Hoshano Josen Gakkai-Shi. 2017;5(2):79–93. (Japanese with English abstract)

14. Tokyo Metropolitan Institute of Public Health. Measurement results of environmental radiation levels in Tokyo 2015. Available from: http://monitoring.tokyo-eiken.go.jp/en/index.html. Accessed 25 June 2019.

15. Wessel P. Free software helps map and display data. EOS, Trans Am Geophys Union. 1991;72:441–8. doi: 10.1029/90EO00319

16. Geospatial Information Authority of Japan. Elevation–Global version. Available from: https://globalmaps.github.io/el.html. Accessed 25 June 2019.

17. Hosoda M, Tokonami S, Sorimachi A, Monzen S, Osanai M, Yamada M, et al. The time variation of dose rate artificially increased by the Fukushima nuclear crisis. Sci Rep. 2011;1:87. doi: 10.1038/srep00087 22355606

18. Minato S. Diagonal Elements Fitting Technique to Improve Response Matrixes for Environmental Gamma Ray Spectrum Unfolding. Radioisot. 2001;50(10):463–71. doi: 10.3769/radioisotopes.50.10_463

19. Hosoda M, Tokonami S, Omori Y, Sahoo SK, Akiba S, Sorimachi A, et al. Estimation of external dose by car-borne survey in Kerala, India. PLoS One. 2015;10(4):e0124433. doi: 10.1371/journal.pone.0124433 25885680

20. Matsuda H, Furukawa S, Kaminishi T, Minato S, A new method for evaluating weak leakage gamma-ray dose using a 3”φ × 3” NaI(Tl) scintillation spectrometer (I) Principle of background estimation method. Rep Gov Ind Res Inst. 1982;31:132–146 (in Japanese).

21. Le TV, Inoue K, Tsuruoka H, Fujisawa M, Arai M, Nguyen LDH, et al. Effective Dose due to Terrestrial Gamma Radiation Estimated in Southern Vietnam by Car-Borne Survey Technique. Radiat Prot Dosimetry. 2018;179(1):18–25. doi: 10.1093/rpd/ncx185 29036482

22. Inoue K, Arai M, Fujisawa M, Saito K, Fukushi M. Detailed Distribution Map of Absorbed Dose Rate in Air in Tokatsu Area of Chiba Prefecture, Japan, Constructed by Car-Borne Survey 4 Years after the Fukushima Daiichi Nuclear Power Plant Accident. PLoS One. 2017;12(1):e0171100. doi: 10.1371/journal.pone.0171100 28129382

23. Hosoda M, Inoue K, Oka M, Omori Y, Iwaoka K, Tokonami S. Environmental Radiation Monitoring and External Dose Estimation in Aomori Prefecture after the Fukushima Daiichi Nuclear Power Plant Accident. Jpn J Health Phys. 2016;51(1):41–50. doi: 10.5453/jhps.51.41

24. Inoue K, Tsuruoka H, Le Van T, Fukushi M. Contribution ratios of natural radionuclides to ambient dose rate in air after the Fukushima Daiichi Nuclear Power Plant accident. J Radioanal Nucl Chem. 2015:1–6. doi: 10.1007/s10967-015-4164-8

25. Inoue K, Hosoda M, Sugino M, Simizu H, Akimoto A, Hori K, et al. Environmental radiation at Izu-Oshima after the Fukushima Daiichi nuclear power plant accident. Radiat Prot Dosimetry. 2012;152(1–3):234–7. doi: 10.1093/rpd/ncs228 22927656

26. Shimo M, Minato S, Sugino M. A Survey of Environmental Radiation in Aichi, Gifu and Mie Prefectures. J Nucl Sci Technol. 1999;41(9):954–964. doi: 10.3327/jaesj.41.954 (Japanese with English abstract)

27. Ministry of Land, Infrastructure, Transport and Tourism. Housing and economic data. http://www.mlit.go.jp/statistics/details/t-jutaku-2_tk_000002.html. (in Japanese) Accessed 4 September 2019.

28. Bureau of Construction, Tokyo Metropolitan Government. Available from: http://www.kensetsu.metro.tokyo.jp/english/index.html. Accessed 25 June 2019.

29. Institute for Community and Life Resources. Available from: http://www.chiikiseikatsu.org/databook2014/databook2014tnk.pdf. Accessed 25 June 2019. (Japanese)

30. Mueck K, Steger F. Wash-Off Effects in Urban Areas. Radiat Prot Dosimetry. 1991;37(1):189–94. doi: 10.1093/oxfordjournals.rpd.a081051

31. Roed J, Andersson K, Barkovsly A, Fogh C, Mishine A, Olsen S, et al. Mechanical decontamination tests in areas affected by the Chernobyl accident. Aug 1998. http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/30/004/30004765.pdf. Accessed 25 June 2019.

32. Tsubokura M, Murakami M, Nomura S, Morita T, Nishikawa Y, Leppold C, Kato S, Kami M. Individual external doses below the lowest reference level of 1 mSv per year five years after the 2011 Fukushima nuclear accident among all children in Soma City, Fukushima: A retrospective observational study. PLoS One. 2017;12(2):e0172305. doi: 10.1371/journal.pone.0172305 28235009

33. Andersson KG, Roed J, Fogh CL. Weathering of radiocaesium contamination on urban streets, walls and roofs. J Environ Radioact. 2002;62(1):49–60. doi: 10.1016/S0265-931X(01)00150-3 12141607

34. Yoshimura K, Saito K, Fujiwara K. Distribution of 137Cs on components in urban area four years after the Fukushima Dai-ichi Nuclear Power Plant accident. J Environ Radioact. 2017;178–179:48–54. doi: 10.1016/j.jenvrad.2017.07.021 28778008


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