The impact of possible modifications to the DS86 dosimetry on neutron risk and relative biological effectiveness

  title={The impact of possible modifications to the DS86 dosimetry on neutron risk and relative biological effectiveness},
  author={Nezahat Hunter and Monty W Charles},
  journal={Journal of Radiological Protection},
  pages={357 - 370}
The current DS86 dosimetry system for the Japanese bomb survivors indicates that neutron doses were so low that they prevent the direct derivation of any useful estimates of neutron risk. However, the large body of thermal neutron activation measurements carried out over many years in Hiroshima and Nagasaki appear to indicate that current DS86 neutron doses may have been significantly underestimated in Hiroshima. An earlier companion paper has provided an update of neutron activation… 



Neutron versus gamma-ray risk estimates. Inferences from the cancer incidence and mortality data in Hiroshima.

The cancer data from Hiroshima can still provide 'prudent' risk estimates for photons, but with the corrected DS86, they do not prove that there is a linear component in the dose dependence for photons.

Estimates of neutron relative biological effectiveness derived from the Japanese atomic bomb survivors.

  • M. Little
  • Medicine
    International journal of radiation biology
  • 1997
Although there are no significant differences between groupings of the solid tumour sites in their estimated neutron relative Biological effectiveness, there are indications that the neutron relative biological effectiveness of solid tumours is lower than that of leukaemia, whether or not adjustments are made to the Hiroshima neutron doses.

Risk Implications of the Neutron Discrepancy in the Hiroshima DS86 Dosimetry System

It is demonstrated that adding neutron dose in Hiroshima consistent with the discrepancy between measurements and DS86 calculations strongly affects gamma ray equivalent dose-response curves inferred from the Hiroshima data, which has important implications for gamma ray risk estimation.

Feasibility of Assessing the Carcinogenicity of Neutrons among Neutron Therapy Patients

A large investigation could detect a fivefold or higher leukemia risk, but would be inadequate to evaluate the risk of solid cancers with long latent periods and therefore would likely not be informative with respect to neutron-related cancer risk in humans.

The present system of quantities and units for radiation protection.

Values of wR constitute an important part of the International Commission on Radiological Protection recommendations and a brief history of the development of higher relative biological effectiveness values for fission neutrons and alpha particles leading to the selection of 20 for wR in each case, is provided.

Radiation-Related Cancer Risks at Low Doses among Atomic Bomb Survivors

Analysis is of solid cancer incidence from 1958–1994, involving 7,000 cancer cases among 50,000 survivors in that dose and distance range, and it is indicated that modification of the neutron dose estimates currently under consideration would not markedly change the conclusions.

Residual 152Eu and 60Co activities induced by neutrons from the Hiroshima atomic bomb.

Present results indicate that systematic errors exist in the DS86 neutrons concerning the source-term spectrum, neutron transport calculations in air, and/or activation measurements.

The quality factor in radiation protection

Early recommendations on radiation protection were primarily concerned with x rays and gamma rays which were deemed to have similar biological effectiveness. The postulated similarity meant that

Neutron RBE values and their relationship to judgements in radiological protection.

  • A. Edwards
  • Environmental Science
    Journal of radiological protection : official journal of the Society for Radiological Protection
  • 1999
This review traces the history of radiological protection judgements concerning the relative biological effectiveness (RBE) for neutrons and quality factor and argues that variations in neutron RBE measurements are large so that for practical purposes pragmatic judgements need to be made.

Age Dependencies in the Modelling of Radiation Carcinogenesis

Comparing the current model for cancers other than leukaemia to a more meaningful alternative shows that age dependencies for leukaemias and other cancers to be less fundamentally different than commonly assumed.