Injuries to persons resulting from the atomic explosions were of the
following types:
A. Burns, from
1. Flash radiation of heat
2. Fires started by the explosions.
B. Mechanical injuries from collapse of buildings, flying debris, etc.
C. Direct effects of the high blast pressure, i.e., straight
compression.
D. Radiation injuries, from the instantaneous emission of gamma rays and
neutrons.
It is impossible to assign exact percentages of casualties to each of
the types of injury, because so many victims were injured by more than
one effect of the explosions. However, it is certain that the greater
part of the casualties resulted from burns and mechanical injures.
Col. Warren, one of America's foremost radioligists, stated it is
probable that 7 per cent or less of the deaths resulted primarily from
radiation disease.
The greatest single factor influencing the occurrence of casualties was
the distance of the person concerned from the center of explosion.
Estimates based on the study of a selected group of 900 patients
indicated that total casualties occurred as far out as 14,000 feet at
Nagasaki and 12,000 feet at Hiroshima.
Burns were suffered at a considerable greater distance from X than any
other type of injury, and mechanical injuries farther out than
radiation effects.
Medical findings show that no person was injured by radioactivity who
was not exposed to the actual explosion of the bombs. No injuries
resulted from persistent radioactivity of any sort.