Atom bomb survivors

Most of the data on radiation health effects have come from medical monitoring of Japanese atomic bomb survivors. For survivors who received radiation exposures up to 0.10 Sv, the iacidence of cancer is no greater than ia the geaeral populatioa of Japanese citizens. For the approximately 1000 survivors who received the highest radiation doses, ie, >2 Sv, there have been 162 cases of cancer. About 70 cases would have been expected ia that populatioa from aatural causes. Of the approximately 76,000 survivors, as of 1995 there have beea a total of about 6,000 cases of cancer, only about 340 more cases than would be expected ia a group of 76,000 Japanese citizens who received only background radiation exposure (59). 

Kato H, Schull W. 1982. Studies of the mortality of A-bomb survivors. Report 7 Part 8, Cancer mortality among atomic bomb survivors, 1950-78. Radiat Res 90 395-432. 

Steinhausler,F. and E. Pohl, Lung Cancer Risk for Miners and Atomic Bomb Survivors and its Relevance to Indoor Radon Exposure, Radiation Protection Dosimetry Vol.7, No.1-4 389-394 (1983). 

Developing forebrain, 0.18-0.55 Gy (estimated dose to prenatally exposed Japanese atomic bomb survivors) Seizures in childhood reduced school performance at least through age 11 years some cases of severe mental retardation by age 17 years 12... 

Yoshimoto, Y., J.V. Neel, W.J. Schull, H. Kato, M. Soda, R. Eto, and K. Mabuchi. 1990. Malignant tumors during the first 2 decades of life in the offspring of atomic bomb survivors. Amer. Jour. Human Genet. 46 1041-1052. 

A significant body of data defines the relationship between radiation dose and cancer incidence. This dataset is primarily from a study of the atomic bomb survivors from Nagasaki and Hiroshima, Japan but also includes data from animal studies and other sources of information. While additional data are continuously collected and... 

A great deal was learned from the atomic bomb survivors. The US military dropped the first atomic bomb on Hiroshima, Japan on 6 August 1945 and a second on Nagasaki, Japan, three days later. The bombs used two different types of radioactive material, 235U in the first bomb and 239Pu in the second. It is estimated that... 

The current health risks associated with exposure to low-dose radiation are extrapolated from high-dose data taken from the Life Span Study of the Japanese atomic bomb survivors. Currently, a linear no threshold extrapolation is recommended. The numerous technical reports and scientific papers about the Japanese A-bomb survivors were widely interpreted as showing that the effects of occupational exposures to radiation would be too small to detect in epidemiological studies. However, questions about the reliability of the A-bomb results were presented by Stewart and Kneale [2]. Their Oxford Childhood Study observed that children whose in utero exposures were as little as 10 to 20 mSv had 40% more childhood leukemias than those who were not exposed. No similar effects are reported in the A-bomb data. Of course, the finding of no effect is not a compelling argument for or against a safe dose. 

Beebe, G.W., Kato, H., and Land, C.E. (1978b). Life Span Study Report Mortality Experience of Atomic Bomb Survivors, 1950-74, RERF TR 1-77 (Radiation Effects Research Foundation, Hiroshima, Japan). 

Blot, W.J., Akiba, S. and Kato, H. (1984). Ionizing radiation and lung cancer A review including preliminary results from a case-control study among A-bomb survivors, in Atomic Bomb Survivor Data Utilization and Analysis, PRENTICE, R.L. and Thompson, D.J., Eds. (SIAM, Philadelphia). 

ICHIMARU, M., ISHIMARU, T., AND Belskv J.L. (1978). Incidence of leukemia in atomic bomb survivors belonging to a fixed cohort in Hiroshima and Nagasaki, 1950-71. Radiation dose, years after exposure, age at exposure, and type of leukemia, Japan J. Radiat. Res. 19,262. 

ISHIMARU, T., Hoshino, T, Ichimaru, M., Okada, H., Tomiyasu, T, Tsuchi-MOTO, T., AND Yamamoto, T. (1969). Leukemia in Atomic Bomb Survivors, Hiroshima-Nagasaki, October 1, 1950 - September 30, I960, ABCC TR 25-... 

Moloney, W.C. and Kastenbaum, M.R. (1955). "Leukemogenic effects of ionizing radiation on atomic bomb survivors in Hiroshima City Science 121,308. 

Tokunaga, M., Norman, J.E., Jr, Asano, M., Tokuoka, S., Ezaki, H., NishimORI, I., AND TSUJI, Y. (1979). Malignant breast tumors among atomic bomb survivors, Hiroshima and Nagasaki, 1950-1974, J. Natl. Cancer Inst. 62,1347. 

Standards and Measurement of Radioactivity for Radiological Use-Medical and Biological Applications Biological Aspects of Radiation Protection Criteria SC 40-1 Atomic Bomb Survivor Dosimetry... 

SC 40-1A Biological Aspects of Dosimetry of Atomic Bomb Survivors Radiation Associated with Medical Examinations Radiation Received by Radiation Employees Operational Radiation Safety... 

Figure 3 illustrates rough dose-response model fits with human data for ionizing radiation and leukemia incidence from atomic bomb survivors (24). Data exist down to about the 10-5 lifetime risk per person exposed. This value is close to the region of regulatory interest, and relatively small risk differences are predicted by the three illustrated models in the dose range up to two orders of magnitude below the last observed dose value (ca. 5 rad). 

The nominal probability coefficient for radionuclides normally used in radiation protection is derived mainly from maximum likelihood estimates (MLEs) of observed responses in the Japanese atomic-bomb survivors. A linear or linear-quadratic dose-response model, which is linear at low doses, is used universally to extrapolate the observed responses at high doses and dose rates to the low doses of concern in radiation protection. The probability coefficient at low doses also includes a small adjustment that takes into account an assumed decrease in the response per unit dose at low doses and dose rates compared with the observed responses at high doses and dose rates. 

The Japanese atomic-bomb survivors also are a potentially important source of data on the dose-response relationship for severe hereditary responses. However, no evidence for inherited genetic effects has been observed in spite of nearly 50 y of study. In the absence of data in humans, estimates of the frequency of radiation-induced hereditary responses have been based primarily on data from studies in mice. 

The conclusion about the uncertainty in the dose-response relationship for radiation stated above takes into account the uncertainty in extrapolating the data at high doses and dose rates in the Japanese atomic-bomb survivors to the lower doses and dose rates of concern in routine exposures of the public. The issue of extrapolation to low doses and dose rates is a matter of considerable controversy and is an important source of uncertainty (NCRP, 1997 2001). Forpurposes of radiation protection, the frequency of responses at low doses and dose rates generally has been assumed to be a factor of two less than MLE of the frequency of responses in the Japanese atomic-bomb... 

However, this option presents some difficulties for radionuclides, because studies of radiation effects in human populations have focused on cancer fatalities as the measure of response and probability coefficients for radiation-induced cancer incidence have not yet been developed by ICRP or NCRP for use in radiation protection. Probabilities of cancer incidence in the Japanese atomic-bomb survivors have been obtained in recent studies (see Section 3.2.3.2), but probability coefficients for cancer incidence appropriate for use in radiation protection would need to take into account available data on cancer incidence rates from all causes in human populations of concern, which may not be as reliable as data on cancer fatalities. Thus, in effect, if incidence were used as the measure of stochastic response for radionuclides, the most technically defensible database on radiation effects in human populations available at the present time (the data on fatalities in the Japanese atomic-bomb survivors) would be given less weight in classifying waste. 

For radionuclides, NCRP reaffirms use of a best estimate (MLE) of the response probability obtained from a linear or linear-quadratic model as derived from data in humans, principally the Japanese atomic-bomb survivors. This model essentially is linear at the low doses of concern to waste classification. Specifically, for purposes of health protection of the public, NCRP reaffirms use of a probability coefficient for fatal cancers (probability per unit effective dose) of 0.05 Sv 1 (ICRP, 1991 NCRP, 1993a). Although this probability coefficient is less rigorous for intakes of some long-lived radionuclides that are tenaciously retained in the body than for other exposure situations, such as external exposure or intakes of short-lived radionuclides (Eckerman et al., 1999), it is adequate for the purpose of generally classifying waste, especially when the lack of data on cancer risks in humans for most chemicals is considered. 

MABUCHI, K., SODA, M., RON, E., TOKUNGA, M., OCHIKUBO, S., SUGI-MOTO, S., IKEDA, T., TERASAKI, M., PRESTON, D.L. and THOMPSON, D.E. (1994). Cancer incidence in atomic bomb survivors. Part I Use of the tumor registries in Hiroshima and Nagasaki for incidence studies, Radiat. Res. 137, S1-S16. 

Sofpni, T., H. Shimba, K. Ohtaki, and A.A. Awa. G-banding Analysis of Chromosome Aberrations in Hiroshima Atomic Bomb Survivors. Radiation Effects Research Foundation Technical Report 13-77. Hiroshima ... 

The Radiation Effects Research Foundation s Life Span Study of atomic bomb survivors has reported that for all solid tumours combined, there is clear evidence of a radiation dose-response relationship. Both excess relative risk and excess absolute risk are larger for individuals exposed as children than for those exposed as adults, and solid tumour risk continues to increase in later years (Kodama et al., 2003). Survivors of the atomic bombs also have increased risk of all kinds of solid tumours, including those of adult life, although the degree of susceptibility varies with age at the time of the bombings and is generally highest early in life. 

Kodama K, Preston Dl, Pierce DA, Shimizu Y, Suyama A, Tahara E (2003) Radiation effects on cancer mortality among atomic bomb survivors. Proc Am Assoc Cancer Res, 44 1278 (Abstract No. 6394). 

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