29
(adult) statures and weights, measured at age 21
or older, of subjects exposed to radiation at age
' £17 indicated that those exposed in Hiroshima
attained a mean height markedly lower than normal and that the degree of retardation diminished
with increasing age at exposure, being greatest in
those exposed at age <5. The effect was more
prominent in boys. The preliminary tabulations
of growth data in the Marshallese children26-45
showed similar trends. Subsequently, the extent of
the thyroid injury documented in the Marshallese
children provided the basis for the present assumption that growth retardation reflected primarily
the results of impaired thyroid function.It is anticipated that when adult (final) anthropometric
measurements becomeavailable, further evalua-
tion of the growth pattern of the Marshallese chil-
dren (including further assessment of the effect of
thyroid hormone administration) will be possible.
G. DEGENERATIVE DISEASES
dividuals >40 vears old have revealed the cardiac
changes expected with aging: arteriosclerosis heart
disease with occasional cardiac decompensation.
Auricular fibrillation has been noted in a few
people; rheumatic heart disease in only two.
Peripheral vascular diseases (thrombophlebitis,
peripheral venous disease, hemorrhoids) appear to
be less common than in Americans. Oscillometric
studies showed peripheral pulses to be exceptionally good, even in older people andin diabetics
(see below). No luetic, metabolic, or nutritional
form of heart disease has been seen.
2. Arthritis
Many Marshallese >40 years of age complain
of joint symptomsin the arms and legs and to a
lesser extent in the lower back. Many,particularly
the older ones, have complained also of vague
muscle pains in the arms and legs. Some older
women develop marked kyphosis in the lower
thoracic-lumbar region which may be related
partly to the squatting or stooping position neces-
therefore, in these studies careful consideration has
sary for cooking over open fires. X rays show many
of the above complaints to be associated with
osteoarthritic changes; but many people with complaintsdo not have definite bone changes. Arthritis
seems no more commonin the exposed than in the
of cardiovascular diseases, arthritis, and other de-
does notdiffer greatly from that among Ameri-
The aging process is accompanied by an increased incidence of degenerative diseases, and irradiated animals have shownincreases both in
general aging phenomenaandin such diseases;
been given to signs of aging andto the incidence
unexposed population, and its general incidence
generative diseases.
cans. Rheumatoid arthritis has rarely been seen.
1. Cardiovascular Diseases
gave positive results in only a few cases (3 of 184
Cardiovascular diseases appear to be no more
prevalent among the Marshailese than in Ameri-
cans or other populations, and no difference was
found betweentheir incidences in the exposed and
unexposed groups. Hypertension appears to be
somewhatless prevalent among the Marshallese
than among Americans. Blood pressures > 140/90
have been recorded in only about 9% of the people,
and the increasing percentage of older people in
the study groups does not seem to haveraised the
incidence of hypertension. Manyof the younger
people, particularly females, have notably lower
blood pressures (90-100/55-65). The generally
lower blood pressures in the Marshallese have been
thought to be related to lower dietary salt intake,7.46 but the gradually increasing use of im-
ported foods of greatersalt content has caused no
apparentincrease in hypertension. Serum sodium
and potassium levels have usually been in the nor-
mal range. Routine chest x rays and ECG’s on in-
S0Cb I 2b
Examination of the sera for “rheumatic factor”
tested in 1959).8
3. Nephroscierosis
Primary kidney disease has not been notedfre-
quently, but nephrosclerosis has occasionally been
seen complicating cardiovascular disease.
4. Aging
Radiation in sublethal doses may reduce longev-
ity in animals and man, [nduction of malignant
transformation is weil documented and accounts
for most of the early deaths. However, develop-
ment of premature senescence with associated degenerative diseases and immunodeficiency, as a
late effect of exposure,is also believed to accountfor
some degree oflife shortening in animals.*7-49 For
humans,definite proof of such effects is lacking,
the only documentedlife-shortening effect being
related to malignancies.59-5! In the Japanese bomb
survivors, the correlation of life-shortening with