4
levels in the Marshallese appeared to be above the
average in the U.S. population.
Dental surveys’ showed no significant differences
in caries rate between exposed and unexposed
groups. However, the incidence and severity of
peridontal disease was slightly greater in the exposed group. It is not known whether or not this
findingis related to radiation effects. The poor oral
hygiene generally observed in the Marshallese had
its usual results; namely, high caries rate in teen-
age children, severe peridontal lesions in adults
(heavy calculus and loss of alveolar bone), and
edentulous mouths in the aged. Radiation exposure
did not appear to have affected developing dentition in the exposed children.
Late effects of radiation. Various parameters
usually associated with aging were measured or
estimated on a 0 to 4-++ scale (skin looseness, elasticity, and senile changes; greying of the hair and
balding; accommodation, visual acuity, and arcus
senilis; hearing; cardiovascular changes including
blood pressure and degrees of peripheral and retinal arteriosclerosis; neuromuscular function; and
hand strength). Comparison of these measure-
ments in exposed and unexposed individuals of the
with the possible exception of suggestive evidence
of increased miscarriages andstillbirths in the exposed women andthe slight retardation of growth
noted in the male children of exposed parents.
BETA IRRADIATION OF THE SKIN
It was impossible to get an accurate estimate of
the radiation dose to the skin. Beta burns of the
skin and epilation appeared about 2 weeks after
exposure, largely on parts of the body not covered
by clothing. About 90% of the people had these
burns, and a smaller number developed spotty
epilation of the scalp. Most of the lesions were
superficial; they exhibited pigmentation and dry,
scaly desquamation, and were associated with little
pain. Rapid healing and repigmentation followed.
Some lesions were deeper, showed wet desquamation, and were more painful. A few burns became
secondarily infected and had to be treated with
antibiotics. Repigmentation of the lesions gradually
took place in most instances, and the skin appeared
normal within a few weeks. However, in about
15% of the people, deeper lesions, particularly
posed group occurred at 5 years after exposure,
too soon, it is believed, to bear any particular relation to radiation exposure. Leukernia surveys including physical findings, studies of white cell
counts and types, alkaline phosphatase staining,
and basophil counts of 4000 white cells showed no
evidence of leukemia or leukemic tendency. One
child in the irradiated group has had slightly ele-
noted on the dorsum ofthe feet, continued to show
lack of repigmentation with varying degrees of
scarring and atrophy of the skin. By 6 years the
only residual effects of beta radiation of the skin
were seen in 10 cases which showed varying degrees of pigment aberrations, scarring, and atrophy
at the site of the former burns. During the past
several years an increased number of pigmented
maculae and moles have been noted in previously
irradiated areas of the skin, but these have appeared
to be quite benign.
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Numerous histopathological studies have been
made,':*> and the changes found have been consistent with radiation damage. At no time have
changes been observed either grossly or microscopically indicative of malignant or premalignant
cardiovascular and arthritis surveys, as well as the
general results of the physical examinations, have
not shown any apparent increased incidence of
degenerative diseases in the exposed people. No
radiation-induced cataracts have been observed in
any of the exposed people.
Genetic effects have not been specifically studied
because of the small number of people involved.
No apparent radiation-induced genetic changes
have been detected on routine physical examination
in the first-generation children of exposed parents,
lived, regrowth of hair occurring about 3 months
after exposure and complete regrowth of normal
hair by six months. No further evidence of epilation has been seen.
An interesting observation noted during the first
few months after exposure was the development
of bluish-brown pigmentation of the semilunar
areas of the fingernails and toenails in about 90%
of the people. By 6 months this pigmentation had
disappeared, having grown out with the nail. The
cause of this phenomenon has not been explained.
same age groups showed no apparentdifferences.
A biological age score was calculated for individuals
and groups by use of an average percentage score.
Life shortening effects of radiation have not been
apparent. As noted, the mortality rate was about
the samein the exposed as in the unexposed people.
The one case of cancer that developed in the ex-
vated basophils but no other positive findings. The
change. Spotty epilation on the heads was short