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explosions were not sufficient to kill more than those people very near
the center of damage (within a few hundred feet at most). Very few
cases of ruptured ear drums were noted, and it is the general feeling
of the medical authorities that the direct blast effects were not
great. Many of the Japanese reports, which are believed to be false,
describe immediate effects such as ruptured abdomens with protruding
intestines and protruding eyes, but no such results were actually
traced to the effect of air pressure alone.

RADIATION INJURIES

As pointed out in another section of this report the radiations from
the nuclear explosions which caused injuries to persons were primarily
those experienced within the first second after the explosion; a few
may have occurred later, but all occurred in the first minute. The
other two general types of radiation, viz., radiation from scattered
fission products and induced radioactivity from objects near the center
of explosion, were definitely proved not to have caused any casualties.

The proper designation of radiation injuries is somewhat difficult.
Probably the two most direct designations are radiation injury and
gamma ray injury. The former term is not entirely suitable in that it
does not define the type of radiation as ionizing and allows possible
confusion with other types of radiation (e.g., infra-red). The
objection to the latter term is that it limits the ionizing radiation
to gamma rays, which were undoubtedly the most important; but the
possible contribution of neutron and even beta rays to the biological
effects cannot be entirely ignored. Radiation injury has the advantage
of custom, since it is generally understood in medicine to refer to
X-ray effect as distinguished from the effects of actinic radiation.
Accordingly, radiation injury is used in this report to mean injury due
only to ionizing radiation.

According to Japanese observations, the early symptons in patients
suffering from radiation injury closely resembled the symptons observed
in patients receiving intensive roentgen therapy, as well as those
observed in experimental animals receiving large doses of X-rays. The
important symptoms reported by the Japanese and observed by American
authorities were epilation (lose of hair), petechiae (bleeding into the
skin), and other hemorrhagic manifestations, oropharyngeal lesions
(inflammation of the mouth and throat), vomiting, diarrhea, and fever.

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