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Radiation in Medicine A Need for Regulatory Reform (1996) / Chapter Skim
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Appendix K: The Linear, No-Threshold Model
Pages 284-289

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From page 284...
... Divided Scientific Opinion, 195~1966 In 1958 the United Nations Scientific Committee on the Effects of Atomic Radiation issued its first report on the effects of radiation exposures in humans (UNSCEAR, 1958~. This report estimated the risk of adverse effects of low-level radiation exposure using both a no-threshold and a threshold model of radiation risk.
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From page 285...
... This conclusion was contested by the Committee on Pathologic Effects of Atomic Radiation of the National Academy of Sciences/National Research Council (NAS/NRC) , which stated unequivocally that "a considerable body of experimental evidence" favored nonlinearity and hence presumably a threshold, and urged that nonlinear relationships between dose and effect should be given greater attention (NAS/NRC, 1959~.
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From page 286...
... The implication of ALARA is that no threshold exists for adverse radiation effects and that any dose, no matter how small, is potentially injurious to exposed individuals. These actions of the NAS/NRC and the AEC completed a major transition in the conceptualization of radiation risk at low doses, and they provided a foundation for the evolution of health physics as a discipline devoted to the protection of workers and the public against small doses of ionizing radiation.
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From page 287...
... It also reflected concern over the growing practice of using dose-response models to estimate hypothetical cancer risks at doses substantially below levels where epidemiological studies have confirmed injury.2 Two additional BEIR reports were issued after the 1980 report of the BEIR III committee. The BEIR IV report, which addressed the health risks of radon and other internally deposited radionuclides (NAS/NRC, 1988)
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From page 288...
... He traces the evolution from the postulate that every dose, no matter how small, has an associated risk of ill health, through venous steps until the final unequivocal statements are reached that radiation follows a linear, no-threshold dose-response relationship, and that all radiation exposure is unsafe. Other recent reports that bear on the issue of extrapolating risks from highdose to low-dose exposure are several reports that directly address mechanisms of response to low-dose exposures.
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From page 289...
... , Committee on Pathological Effects of Atomic Radiation. A Commentary on the Report of the United Nations Scientific Committee on the Effects of Atomic Radiation.
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  • permissible dose
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