Radiation and Environmental Biophysics

, Volume 45, Issue 2, pp 79–91 | Cite as

Effective dose of A-bomb radiation in Hiroshima and Nagasaki as assessed by chromosomal effectiveness of spectrum energy photons and neutrons

  • M. S. SasakiEmail author
  • S. Endo
  • Y. Ejima
  • I. Saito
  • K. Okamura
  • Y. Oka
  • M. Hoshi
Original Paper


The effective dose of combined spectrum energy neutrons and high energy spectrum γ-rays in A-bomb survivors in Hiroshima and Nagasaki has long been a matter of discussion. The reason is largely due to the paucity of biological data for high energy photons, particularly for those with an energy of tens of MeV. To circumvent this problem, a mathematical formalism was developed for the photon energy dependency of chromosomal effectiveness by reviewing a large number of data sets published in the literature on dicentric chromosome formation in human lymphocytes. The chromosomal effectiveness was expressed by a simple multiparametric function of photon energy, which made it possible to estimate the effective dose of spectrum energy photons and differential evaluation in the field of mixed neutron and γ-ray exposure with an internal reference radiation. The effective dose of reactor-produced spectrum energy neutrons was insensitive to the fine structure of the energy distribution and was accessible by a generalized formula applicable to the A-bomb neutrons. Energy spectra of all sources of A-bomb γ-rays at different tissue depths were simulated by a Monte Carlo calculation applied on an ICRU sphere. Using kerma-weighted chromosomal effectiveness of A-bomb spectrum energy photons, the effective dose of A-bomb neutrons was determined, where the relative biological effectiveness (RBE) of neutrons was expressed by a dose-dependent variable RBE, RBE(γ, D n), against A-bomb γ-rays as an internal reference radiation. When the newly estimated variable RBE(γ, D n) was applied to the chromosome data of A-bomb survivors in Hiroshima and Nagasaki, the city difference was completely eliminated. The revised effective dose was about 35% larger in Hiroshima, 19% larger in Nagasaki and 26% larger for the combined cohort compared with that based on a constant RBE of 10. Since the differences are significantly large, the proposed effective dose might have an impact on the magnitude of the risk estimates deduced from the A-bomb survivor cohort.


Chromosome Aberration Relative Biological Effectiveness Fission Neutron Neutron Dose Spectrum Energy Neutron 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



We are grateful to the Radiation Effects Research Foundation (RERF) for making use of the chromosome aberration database ca1993. RERF is a private foundation founded by the Japanese Ministry of Health, Labor and Welfare, and the US Department of Energy through the US National Academy of Sciences. The conclusions in this report are those of the authors and do not necessarily reflect the scientific judgment of RERF or its funding agencies. We wish to acknowledge Albrecht M. Kellerer for the most helpful critical discussions during preparation of this manuscript. The experiments using the YAYOI nuclear reactor were carried out as a collaborative research project chaired by Itsuro Kimura. This work was supported in part by the Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Culture, Sports and Technology of Japan.


  1. 1.
    ICRP (1991) Publication 60. The 1990 recommendations of the International Commission on Radiological Protection. Annals of ICRP 21. Pergamon Press, New YorkGoogle Scholar
  2. 2.
    Preston DL, McCornney ME, Awa AA (1988) Comparison of the dose–response relationship for chromosome aberration frequencies between the T65D and DS86 dosimetries. Radiation Effects Research Foundation Technical Report TR-88Google Scholar
  3. 3.
    Preston DL, Shimizu Y, Pierce DA, Suyama A, Mabuchi K (2003) Studies of mortality of atomic bomb survivors. Report 13: solid cancer and noncancer disease mortality: 1950–1997. Radiat Res 160:381–407CrossRefGoogle Scholar
  4. 4.
    Preston DL, Pierce DA, Shimizu Y, Cullings HM, Fujita S, Funamoto S, Kodama K (2004) Effect of recent changes in atomic bomb survivor dosimetry on cancer mortality risk estimates. Radiat Res 162:377–389CrossRefGoogle Scholar
  5. 5.
    RERF (1987) US–Japan joint reassessment of atomic bomb radiation dosimetry in Hiroshima and Nagasaki. Final Report. In: WC Roesch (ed) Vols 1 and 2. Radiation Effects Research Foundation, HiroshimaGoogle Scholar
  6. 6.
    RERF (2005) Reassessment of the atomic bomb radiation dosimetry for Hiroshima and Nagasaki: Dosimetry system 2002, DS02. In: RW Young, GD Kerr (eds) Vols 1 and 2. Radiation Effects Research Foundation, HiroshimaGoogle Scholar
  7. 7.
    ICRP (2003) Publication 92. Relative biological effectiveness (RBE), quality factor (Q), and radiation weighting factor (w R). International Commission on Radiological Protection. Ann. ICRP 33, Pergamon Press, New YorkGoogle Scholar
  8. 8.
    Straume T (1995) High-energy gamma rays in Hiroshima and Nagasaki: Implications for risk and w R. Health Phys 69:954–956CrossRefGoogle Scholar
  9. 9.
    Sasaki MS, Kobayashi K, Hieda K, Yamada T, Ejima Y, Maezawa H, Furusawa Y, Ito T, Okada S (1989) Induction of chromosome aberrations in human lymphocytes by monochromatic X-rays of quantum energy between 4.8 and 14.6 keV. Int J Radiat Biol 56:975–988CrossRefGoogle Scholar
  10. 10.
    Sasaki MS (1991) Primary damage and fixation of chromosomal DNA as probed by monochromatic soft X-rays and low-energy neutrons. In: Fielden EM, O‘Neil P (eds) The early effects of radiation on DNA 54:369–384Google Scholar
  11. 11.
    Schmid E, Krumrey M, Ulm G, Roos H, Regulla D (2003) Maximum low-dose RBE of 17.4 and 40 keV monochromatic X-rays for the induction of dicentric chromosomes in human lymphocytes. Radiat Res 160:499–504CrossRefGoogle Scholar
  12. 12.
    Krumrey M, Ulm G, Schmid E (2004) Dicentric chromosomes in monolayers of human lymphocytes produced by monochromatized synchrotron radiation with photon energies from 1.83 keV to 17.4 keV. Radiat Environ Biophys 43:1–6CrossRefGoogle Scholar
  13. 13.
    Roos H, Schmid E (1998) Analysis of chromosome aberrations in human peripheral lymphocytes induced by 5.4 keV X-rays. Radiat Environ Biophys 36:251–254CrossRefGoogle Scholar
  14. 14.
    Regulla D, Panzer W, Schmid E, Stepha G, Harder D (2001) Detection of elevated RBE in human lymphocytes exposed to secondary electrons from x-irradiated metal surface. Radiat Res 155:744–747CrossRefGoogle Scholar
  15. 15.
    Schmid E, Regulla D, Kramer H-M, Harder D (2002) The effect of 29 kV X-rays on the dose response of chromosome aberrations in human lymphocytes. Radiat Res 158:771–777CrossRefGoogle Scholar
  16. 16.
    Endo S, Hoshi M, Takada J, Takatsuji T, Ejima Y, Saigusa S, Tachibana A, Sasaki MS (2006) Development, beam characterization and chromosomal effectiveness of X-rays of RBC characteristic X-ray generator. J Radiat Res (in press)Google Scholar
  17. 17.
    Schmid E, Bauchinger M, Streng S, Hahrstedt U (1984) The effect of 220 kVp X-rays with different spectra on the dose response of chromosome aberrations in human lymphocytes. Radiat Environ Biophys 23:303–309CrossRefGoogle Scholar
  18. 18.
    Lloyd DC, Edwards AA, Prosser JS (1986) Chromosome aberrations induced in human lymphocytes by in vitro acute x and gamma radiation. Radiat Prot Dosimetry 15:83–88Google Scholar
  19. 19.
    Guerrero-Carbajal C, Edwards AA, Lloyd DC (2003) Induction of chromosome aberration in human lymphocytes and its dependence on X-ray energy. Radiat Prot Dosimetry 106:131–135Google Scholar
  20. 20.
    Lloyd DC, Purrott RJ, Dolphin GW, Bolton D, Edwards AA, Corp MJ (1975) The relationship between chromosome aberrations and low LET dose to human lymphocytes. Int J Radiat Biol 28:75–90CrossRefGoogle Scholar
  21. 21.
    Bauchinger M, Schmid E, Streng S, Dresp J (1983) Quantitative analysis of the chromosome damage at first division of human lymphocytes after 60Co γ-irradiation. Radiat Environ Biophys 22:225–229CrossRefGoogle Scholar
  22. 22.
    Schmid E, Braselmann H, Nahrstedt U (1995) Comparison of γ-ray induced dicentric yields in human lymphocytes measured by conventional analysis and FISH. Mutat Res 348:125–130CrossRefGoogle Scholar
  23. 23.
    Schmid E, Hieber L, Heinzmann U, Roos H, Kellere AM (1996) Analysis of chromosome aberrations in human peripheral lymphocytes induced by in vitro α-particle irradiation. Radiat Environ Biophys 35:179–184CrossRefGoogle Scholar
  24. 24.
    Sasaki MS, Takatsuji T, Ejima Y (1998) The F value cannot be ruled out as a chromosomal fingerprint of radiation quality. Radiat Res 150:253–258CrossRefGoogle Scholar
  25. 25.
    Sasaki MS (2003) Chromosomal biodosimetry by unfolding a mixed Poisson distribution: a generalized model. Int J Radiat Biol 79:83–97CrossRefGoogle Scholar
  26. 26.
    Norman A, Sasaki MS (1966) Chromosome-exchange aberrations in human lymphocytes. Int J Radiat Biol 11:321–328CrossRefGoogle Scholar
  27. 27.
    Norman A (1967) Multi-hit aberrations. In: Evans HJ, Court Brown WM, McLean AS (eds) Human radiation cytogenetics. North Holland Pub. Co., Amsterdam, pp 53–57Google Scholar
  28. 28.
    Schmid E, Rimpl G, Bauchinger M (1974) Dose–response relation of chromosome aberrations in human lymphocytes after in vitro irradiation with 3-MeV electrons. Radiat Res 57:228–238CrossRefGoogle Scholar
  29. 29.
    Purrott RJ, Reeder EJ (1977) Chromosome aberration yields induced in human lymphocytes by 15 MeV electrons given at a conventional dose-rate and in microsecond pulses. Int J Radiat Biol 31:251–256CrossRefGoogle Scholar
  30. 30.
    Attix FH (1986) Introduction to radiological physics and radiation dosimetry. Wiley, New YorkGoogle Scholar
  31. 31.
    Sasaki MS, Saigusa S, Kimura I, Kobayashi T, Ikushima T, Kobayashi K, Saito I, Sasuga N, Oka Y, Ito T, Kondo S (1992) Biological effectiveness of fission neutrons: energy dependency and its implication for the risk assessment. In: Proceedings of International Conference on Radiation Effects and Protection. pp 31–35Google Scholar
  32. 32.
    Vandenbosch R, Huizenga JR (1972) Nuclear fission. Academic, New YorkGoogle Scholar
  33. 33.
    Kerr GD, Pace JV III, Mendelsohn E, Loewe WE, Kaul DC, Dolatshahi F, Egbert SD, Gritzner M, Scott WH Jr, Kosako T, Kanda K (1987) Transport of initial radiations in air over ground. In: US–Japan Joint Reassessment of Atomic Bomb Radiation Dosimetry in Hiroshima and Nagasaki. Final report, Vol. 1., Radiation Effects Research Foundation, Hiroshima, pp 66–142Google Scholar
  34. 34.
    Hoshi M, Takeoka S, Tsujimura T, Kuroda T, Kawami M, Sawada S (1988) Dosimetric evaluation of 252Cf beam for the use in radiobiology studies at Hiroshima University. Phys Med Biol 33:473–480CrossRefGoogle Scholar
  35. 35.
    IAEA (2001) Cytogenetic analysis for radiation dose assessment: a manual. Internationnal Atomic Energy Agency Technical Reports Series No. 405, ViennaGoogle Scholar
  36. 36.
    Stram DO, Sposto R, Preston D, Abrahamson S, Honda T, Awa AA (1993) Stable chromosome aberrations among A-bomb survivors: an update. Radiat Res 136:29–36CrossRefGoogle Scholar
  37. 37.
    Kodama Y, Pawel D, Nakamura N, Preston D, Honda T, Itoh M, Nakano M, Ohtake K, Funamoto S, Awa AA (2001) Stable chromosome aberrations in atomic bomb survivors: results from 25 years of investigation. Radiat Res 156:337–346CrossRefGoogle Scholar
  38. 38.
    Hubbell JH (1982) Photon mass attenuation and energy-absorption coefficients from 1 keV to 20 MeV. Int J Appl Radiat Isot 33:1269–1290CrossRefGoogle Scholar
  39. 39.
    Papworth DG (1970) Testing and fitting frequency distribution. Appendix to “Savage JRK. Sites of radiation induced chromosome exchanges”. In: Ebert M, Howard A (eds) Current topics in radiation research, vol VI. North Holland Pub. Co., Amsterdam, pp 130–194Google Scholar
  40. 40.
    Kellerer AM, Rossi HH, The theory of dual radiation action. Curr Topics Radiat Res. Quart 8:85–158Google Scholar
  41. 41.
    Schmid E, Schraube H, Bauchinger M (1998) Chromosome aberration frequencies in human lymphocytes irradiated in a phantom by a mixed beam of fission neutrons and γ-rays. Int J Radiat Biol 73:263–267CrossRefGoogle Scholar
  42. 42.
    Schmid E, Schlegel D, Guldakke S, Kapsch R-P (2003) RBE of nearly monoenergetic neutrons at energies of 36 keV–14.6 MeV for induction of dicentrics in human lymphocytes. Radiat Environ Biophys 42:87–94CrossRefGoogle Scholar
  43. 43.
    Edwards AA (1997) The use of chromosomal aberrations in human lymphocytes for biological dosimetry. Radiat Res Suppl 148:S39–S44Google Scholar
  44. 44.
    Dobson RL, Straume T, Carrano AV, Minkler JL, Deaven LL, Littlefield LG, Awa AA (1991) Biological effectiveness of neutrons from Hiroshima bomb replica: results of a collaborative cytogenetic study. Radiat Res 128:143–149CrossRefGoogle Scholar
  45. 45.
    Nikjoo H, O’Neill P, Terrissol M, Goodhead DT (1999) Quantitative modeling of DNA damage using Monte Carlo track structure method. Radiat Environ Biophys 38:31–38CrossRefGoogle Scholar
  46. 46.
    Kellerer AM, Nekolla E (1997) Neutron versus γ-ray risk estimates: inferences from the cancer incidence and mortality data in Hiroshima. Radiat Environ Biophys 36:73–83CrossRefGoogle Scholar
  47. 47.
    Kellerer AM (1999) The effects of neutrons in Hiroshima. Implications for the risk estimates. C R Acad Sci Paris 322:229–237Google Scholar
  48. 48.
    Preston DL, Sposto R (1991) RBE and dose response functions. RERF Update 3:3–4Google Scholar
  49. 49.
    Little MP (1997) Estimates of neutron relative biological effectiveness derived from the Japanese atomic bomb survivors. Int J Radiat Biol 72:715–726CrossRefGoogle Scholar
  50. 50.
    Rühm W, Walsh L, Chomentowski M (2003) Choice of model and uncertainties of the gamma-ray and neutron dosimetry in relation to the chromosome aberrations data in Hiroshima and Nagasaki. Radiat Environ Biophys 42:119–128CrossRefGoogle Scholar
  51. 51.
    Pierce DA, Shimizu Y, Preston DL, Veath M, Mabuchi K (1996) Studies of the mortality of atomic bomb survivors. Report 12, Part I. Cancer: 1950–1990. Radiat Res 146:1–12CrossRefGoogle Scholar
  52. 52.
    Radford IR (2004) Chromosomal rearrangement as the basis for human tumorigenesis. Int J Radiat Biol 80:543–557CrossRefGoogle Scholar
  53. 53.
    Pierce DA, Stram DO, Vaeth M (1990) Allowing for random errors in radiation exposure estimates for the atomic bomb survivor data. Radiat Res 123:175–284CrossRefGoogle Scholar
  54. 54.
    Dietze G (1995) Problems with radiation weighting factors for neutrons. In. Hargen U, Harder D, Jung H, Streffer C (eds) Radiation research 1985–1995. In: Proceedings of the 10th International Congress on Radiation Research, Würzburg, pp 169–172Google Scholar
  55. 55.
    Young RW, Egbert SD, Cullings HM, Kerr GD, Imanaka T (2005) Survivor dosimetry. Part B. DS02 free-in-air neutron and gamma tissue kerma relative to DS86. In: Young RW, Kerr GD (eds) Reassessment of the atomic bomb radiation dosimetry for Hiroshima and Nagasaki: dosimetry system 2002, DS02 vol 2. Radiation Effects Research Foundation, Hiroshima, pp 848–857Google Scholar
  56. 56.
    Kellerer AM, Rühm W, Walsh L (2006) Indications of the neutron effect contribution in the solid cancer data of the A-bomb survivors. Health Phys 90:554–564CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • M. S. Sasaki
    • 1
    Email author
  • S. Endo
    • 2
  • Y. Ejima
    • 3
  • I. Saito
    • 4
  • K. Okamura
    • 4
  • Y. Oka
    • 4
  • M. Hoshi
    • 2
  1. 1.Radiation Biology CenterKyoto UniversityKyotoJapan
  2. 2.Research Institute for Radiation Biology and MedicineHiroshima UniversityHiroshimaJapan
  3. 3.Hiroshima Prefectural College of Health ScienceGakuen-cho, MiharaJapan
  4. 4.Nuclear Professional SchoolUniversity of TokyoTokai-mura, IbarakiJapan

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