RADIATION INJURIES

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.
Epilation was one of the most spectacular and obvious
findings. The appearance of the epilated patient was typical.
The crown was involved more than the sides, and in

many instances the resemblance to a monk’s tonsure was
striking. In extreme cases the hair was totally lost. In some
cases, re-growth of hair had begun by the time patients
were seen 50 days after the bombing. Curiously, epilation
of hair other than that of the scalp was extremely unusual.
Petechiae and other hemorrhagic manifestations were
striking findings. Bleeding began usually from the gums
and in the more seriously affected was soon evident from
every possible source. Petechiae appeared on the limbs and
on pressure points. Large ecchymoses (hemorrhages under
the skin) developed about needle punctures, and wounds
partially healed broke down and bled freely. Retinal hemorrhages
occurred in many of the patients. The bleeding
time and the coagulation time were prolonged. The platelets
(coagulation of the blood) were characteristically reduced
in numbers.
Nausea and vomiting appearing within a few hours after
the explosion was reported frequently by the Japanese. This
usually had subsided by the following morning, although
occasionally it continued for two or three days. Vomiting
was not infrequently reported and observed during the
course of the later symptoms, although at these times it
generally appeared to be related to other manifestation of
systemic reactions associated with infection.
Diarrhea of varying degrees of severity was reported and
observed. In the more severe cases, it was frequently bloody.
For reasons which are not yet clear, the diarrhea in some
cases was very persistent.
Lesions of the gums, and the oral mucous membrane,
and the throat were observed. The affected areas became
deep red, then violacious in color; and in many instances
ulcerations and necrosis (breakdown of tissue) followed.
Blood counts done and recorded by the Japanese, as well
as counts done by the Manhattan Engineer District Group,
on such patients regularly showed leucopenia (low-white
blood cell count). In extreme cases the white blood cell
count was below 1,000 (normal count is around 7,000). In
association with the leucopenia and the oropharyngeal lesions,
a variety of other infective processes were seen.
Wounds and burns which were healing adequately suppurated
and serious necrosis occurred. At the same time, similar
ulcerations were observed in the larynx, bowels, and in
females, the gentalia. Fever usually accompanied these lesions.
Eye injuries produced by the atomic bombings in both
cities were the subject of special investigations. The usual
types of mechanical injuries were seen. In addition, lesions
consisting of retinal hemorrhage and exudation were observed
and 75% of the patients showing them had other
signs of radiation injury.
The progress of radiation disease of various degrees of
severity is shown in the following table:

Day after Explosion Most Severe Moderately Severe Mild
1. 1. Nausea and vomiting 1. Nausea and vomiting
2. after 1-2 hours. after 1-2 hours.
3. NO DEFINITE SYMPTOMS
4.
5. 2. Diarrhea
6. 3. Vomiting NO DEFINITE SYMPTOMS
7. 4. Inflammation of the mouth and throat
8. 5. Fever
9. 6. Rapid emaciation
10. Death NO DEFINITE SYMPTOMS
11. (Mortality probably 2. Beginning epilation.
12. 100%)