From the Uranium Information Centre (UIC) in Australia, Nuclear Issues Briefing Paper No. 29.
The Effects of the Hiroshima and Nagasaki BombsThe total number of casualties at the Japan bomb sites is estimated at around 200,000. Estimates of casualties is a complicated affair, and a detailed discussion and breakdown of figures can be found at atomicarchive.com.
The devastating effects of both kinds of bombs depended essentially upon the energy released at the moment of the explosion, causing immediate fires, destructive blast pressures, and extreme local radiation exposures. Since the bombs were detonated at a height of some 600 metres above the ground, very little of the fission products were deposited on the ground beneath. Some deposition occurred however in areas near to each city, owing to local rainfall occurring soon after the explosions. This happened at positions a few kilometres to the east of Nagasaki, and in areas to the west and north-west of Hiroshima....
In Hiroshima, of a resident civilian population of 250 000 it was estimated that 45 000 died on the first day and a further 19 000 during the subsequent four months. In Nagasaki, out of a population of 174 000, 22 000 died on the first day and another 17 000 within four months. Unrecorded deaths of military personnel and foreign workers may have added considerably to these figures....
From the estimated radiation levels, however, it is apparent that radiation alone would not have been enough cause death in most of those exposed beyond a kilometre of the ground zero below the bombs. Most deaths appear to have been from the explosion rather than the radiation....
From the UIC paper:
The atmospheric testing of nuclear weapons up to 1963 caused people to be exposed to radiation in a quite different way. The Japanese atomic bombs had caused lethal exposures locally from radiation at the time of the explosions, but very little radiation more than a few kilometres away. On the other hand, subsequent atmospheric tests did not cause any substantial direct exposures of people at the time of the tests. However, the fission products released into the atmosphere caused the whole world population to be exposed to very low but continuing annual doses from fallout. In at least two instances these fission products also caused substantial irradiation to small populations exposed to local fallout close to the site of testing.
A Hiroshima Victim Remembers
CBS television reporter David R. Ford visited the Atomic Bomb Hospital in Hiroshima, twenty years to the day the bomb fell on that city. He interviewed a woman there suffering from terminal radiation poisoning. She had no hair or nose, and a bandage around her eyes. She recounted the day that destroyed her life and changed the world:
"I was 13. I was in our school yard chatting with schoolmates, waiting for the bell to ring for school to begin. I saw a blue-red flash. It was like another sun. Minutes later, thousands of people were screaming in agony. Many were naked from the concussion, their bodies black. Blood was coming from all their body openings. For many, the flesh had been stripped, and hung so that one could see the bones. For some, it was like someone cut you with a razor at least a quarter-inch deep from shoulder to shoulder, then pulled the meat all the way down to your hips. Then burned you with a blow torch. I didn't know then how badly I was injured. A school friend raised her hand for me to help her. I reached for her hand. The skin came off like a glove, to the elbow. I vomited. Thousands of people were screaming and crawling to the river, desperate for water. As they drank, they died in horrible pain, filling the river like pieces of driftwood."
Pause. Think. Feel. Only silence is appropriate at this point.