Pr ed ny at ie te
a.
2
4
—
oo
BIOLOGY AND MEDICINE
UNCLASSIFIED
Tumor Incidence
A short-term preliminary study of the incidence of tumors in general among the irradiated
survivors in Hiroshima suggests an increased rate related to proximity to the hypocenter. _
This two-fold increase over the control population needs to be studied further. An increased
incidence of carcinomas of the lung, stomach, breast, ovary, and uterus was noted. Comparable
data from Nagasaki do not show an increase.
Effects in Children
Growth and development of children have not proved a useful index since changes, if any,
cannot be clearly ascribed to radiation effects, Better dosage data, however, will be of assistance in constructing a dose-effect curve which may indicate some meaningful correlations.
Fe mat ets net oe
AM ee
Microcephaly(small skull and brain) in children exposed in utero has been a fairly regu-
lar occurrence following exposure of women carrying a fetus of less than four months gestational age. In 15 children the condition was found to be associated with retarded mentality.
Another 16 children had the condition without mental retardation.
Premature Aging
Accelerated aging, if it occurs in man, cannot as yet be determined from the data.
Other Findings
Specific or general changes of a medical nature in adults have not been identified. To the
clinicians most of the irradiated subjects are grossly normal; exposure has not caused new
clinical syndromes to appear. The data, however, are now being developed for machine analysis and unsuspected correlations may yet be discovered.
The “A-Bomb Survivors” have a chronic psychological problem with frequentacute exacerbations. Remembrance, identification as being a survivor, news of “Another A-BombDeath,” etc., create repeated stresses which may bias the data.
Future Program
The future program is based on a defined sample of exposed and normal subjects maintained under close surveillance. The epidemiological concept is prospective and selective
rather than one of recording as much data on as many patients as possible whenever the opportunity presents itself. Although many of the epidemiological techniques and tools needed
to conduct the ABCC study have been used before, this combined application to such a large
population with so many variables, over and above the variable of radiation dosage, has never
before been attempted. The solutions to the methodological problems will be a highly important product of the study.
Longevity as an end point for evaluating radiation effects will receive special attention.
Cancer, leukemia, hypertension, arteriosclerosis, and cataract will be the major defects to
be looked for and evaluated, but the current systematic machine analyses may at any time
direct the attention of the clinical groups toward other medical conditions. More precisely
individualized radiation dosimetry will be of great value in getting at the threshold versus no
threshold problem of the effects of acute radiation in man.
UNCLASSIFIED
29
RCHIVES