page_title: Effects of nuclear explosions on human health
section_title: Types of radioactive exposure after a nuclear attack
hierarchical_section_title: Effects of nuclear explosions on human health / Types of radioactive exposure after a nuclear attack
caption_attribution_description: General notes: Use War and Conflict Number 1244 when ordering a reproduction or requesting information about this image.
context_page_description: The medical effects of the atomic bomb on Hiroshima upon humans can be put into the four categories below, with the effects of larger thermonuclear weapons producing blast and thermal effects so large that there would be a negligible number of survivors close enough to the center of the blast who would experience prompt/acute radiation effects, which were observed after the 16 kiloton yield Hiroshima bomb, due to its relatively low yield:
  Initial stage—the first 1–9 weeks, in which are the greatest number of deaths, with 90% due to thermal injury and/or blast effects and 10% due to super-lethal radiation exposure.
  Intermediate stage—from 10–12 weeks. The deaths in this period are from ionizing radiation in the median lethal range - LD50
  Late period—lasting from 13–20 weeks. This period has some improvement in survivors' condition.
  Delayed period—from 20+ weeks. Characterized by numerous complications, mostly related to healing of thermal and mechanical injuries, and if the individual was exposed to a few hundred to a thousand Millisieverts of radiation, it is coupled with infertility, sub-fertility and blood disorders.
context_section_description: In a nuclear explosion the human body can be irradiated by at least three processes. The first, and most major, cause of burns is due to thermal radiation and not caused by ionizing radiation.
  Thermal burns from infrared heat radiation, these would be the most common burn type experienced by personnel.
  If people come in direct contact with fallout, beta burns from shallow ionizing beta radiation will be experienced, the largest particles (visible to the naked eye) in local fallout would be likely to have very high radioactivity because they would be deposited so soon after detonation; this fraction of the total fallout is called the prompt or local fallout fraction. It is likely that one such particle upon the skin would be able to cause a localized beta burn. This local fallout, termed Bikini snow after the Pacific island weapon tests, was experienced by the crew on the deck of the Lucky Dragon fishing ship following the explosion of the 15 megaton Shrimp device in the Castle Bravo event. However, these particular decay particles (beta particles) are very weakly penetrating and have a short range, requiring almost direct contact between fallout and personnel to be harmful.
  Rarer still would be personnel who experience radiation burns from highly penetrating gamma radiation. This would likely cause deep gamma penetration within the body, which would result in uniform whole body irradiation rather than only a surface burn. In cases of whole body gamma irradiation (c. 10 Gy) due to accidents involving medical product irradiators, some of the human subjects have developed injuries to their skin between the time of irradiation and death.
  In the picture above, the normal clothing (a kimono) that the woman was wearing attenuated the far reaching thermal radiation; the kimono, however, would  naturally have been unable to attenuate any gamma radiation, if she were close enough to the weapon to have experienced any, and it would be likely that any such penetrating radiation effect would be evenly applied to her entire body. Beta burns would likely be all over the body if there was contact with fallout after the explosion, unlike thermal burns, which are only ever on one side of the body, as heat radiation infrared naturally does not penetrate the human body. In addition, the pattern on her clothing has been burnt into the skin by the thermal radiation. This is because white fabric reflects more visible and infrared light than dark fabric. As a result, the skin underneath dark fabric is burned more than the skin covered by white clothing.
  There is also the risk of internal radiation poisoning by ingestion of fallout particles, if one is in a fallout zone.
caption: Japanese woman (one of the Hiroshima Maidens) suffering burns from thermal radiation after the United States dropped nuclear bombs on Japan.
exif: {}