gms | German Medical Science

27th German Cancer Congress Berlin 2006

German Cancer Society (Frankfurt/M.)

22. - 26.03.2006, Berlin

What were the radiation induced effects of the atomic bombs on Hiroshima and Nagasaki in August 1945?

Meeting Abstract

Search Medline for

27. Deutscher Krebskongress. Berlin, 22.-26.03.2006. Düsseldorf, Köln: German Medical Science; 2006. DocIS023

The electronic version of this article is the complete one and can be found online at:

Published: March 20, 2006

© 2006 Distel.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



The dropping of the atomic bombs in Hiroshima and Nagasaki started a new century of war and analogous to this, showed effects on individuals which were not observed before. Very early effects were caused by the heat, the blast and high radiation doses near the isocenter of the explosion. The acute radiation effects caused anorexia, vomiting, nausea, diarrhoea, epilation, a suppression of the immune system and, mainly by the collapse of the immune system, the radiation disease. The dose causing death of 50% of people was estimated to be about 3 Sv. About 250 000 individuals died immediately or within 8 weeks after the explosion. About 280 000 people survived the first few weeks, leaving an enormous amount of humans which were exposed to ionising radiation ranging from millisievert to a few Sv with an average of about 200 mSv. Long-term effects were studied initially by the Atomic Bomb Casualty Commission and since 1975 by the Radiation Effects Research Foundation (RERF). The Life Span Study started in 1950, including 86 611exposed individuals and a suitable control group. Individual dosimetry was performed for all of these individuals. Of interest were genetic and somatic mutations in survivors, benign tumours, leukaemia and cancer risk and cancer mortality, noncancer disease and mortality. Additionally growth impairment, mental retardation and mortality among about 3000 children exposed to atomic-bomb radiation in utero were studied. Impressing findings were the different patterns of leukaemia and solid cancers. Leukaemia occurred very soon after the exposition and subsided within 10 years to background level. In contrast, the risk of solid tumours arose much later, is continuous today and will persist a lifetime long. An important finding was the much higher lifelong risk of individuals exposed in childhood compared to individuals exposed as adults and a much stronger decline of the excess relative risk in groups exposed in childhood than in adults. In children exposed to radiation in utero between 8 to 15 weeks after conception, radiation has a negative effect on intellectual performance. Most of the effects do not appear at a low-dose radiation and therefore have a threshold. However, mutations and cancer risk have a linear dose-response, which illustrates that even a low dose has a risk for developing a cancer, yet it has a small probability.