36
on the assimilation, excretion. and body burden of
radionuclides.
Medical histories of the intervals between the examiurfations in 1959 and 1960 were, for the most
part, uneventful and revealed no major epidemics
of disease. Several deaths had occurred and new
births were reported. In the exposed group, two
deaths occurred and in the unexposed group,
three. Two of the latter were due to influenza acquired during an epidernic on Kwajalein.
The four deaths that have occurred in the exposed people since exposure represent a mortality
rate of 8.1 per 1000 population, compared with 8.3
for the comparison population and 6.8 for the
Marshall Islands as a whole. A review of the dirth
rate of the exposed group over the past 6 years
seems to indicate no noticeable effect of their exposure on fertility. The 24 births represent a rate of
48 per 1000 population, compared with 37.3 for
the Marshall Islands (1957). The 20 births over a
3-year period for the comparison population represent a rate of 62 per 1000 population. A somewhat greater incidence of miscarriages and stillbirths
has been noted in the exposed women, but be-
cause of the paucity of vital statistics in the Marshallese and the small number of people involved,
the data are not readily amenable to statistical
analysis.
Physical examinations showed the exposed andthe
unexposed people to be generally in a state of good
health. No diseases were noted that could be
directly related to radiation effects. The incidence
of various disorders in both adults and children
was about the samein the exposed and unexposed
groups.
In connection with growth and development studies,
a project on the verification of accuracy of ages of
the children has not been completed and, therefore, the suggestive evidence previously presented
of possible lag in statural growth in the exposed
children must await confirmation. It was noted
however, that in the 6-year chronological age
group, three boys andonegir! outof five boys and
two girls in the exposed group exhibited signif-
cantly retarded skeletal maturation as judged by
X-ray examination. The birth dates of these children seemed to be fairly well established.
118Sb0b
A cardiovascular survey of the adults showed no
outstanding differences between the exposed and
unexposed groups. The people appeared to have
less hypertension on the whole than 1s noted in
people in the continental United States.
An arthritis survey showed no great differences between the exposed and the unexposed people, and
about the same incidence as is seen in American
populations.
An ophthalmological survey showed no remarkable
differences between the exposed and unexposed
groups except possibly a slightly greater number
of cases of pterygii, pingueculae, and corneal scars
in the exposed group. It is not know whetherthis
finding is of any significance in relation to their
radiation exposure. Slit-lamp observations showed
no opacities of the lens characteristic of radiation
exposure. As a whole, visual and accomodation
levels in the Marshallese appeared to be above the
average in the US. population.
A dental survey showed no significant differences
in either caries rate or incidence of peridontaldisease between exposed and unexposed groups. The
poor oral hygiene generally observed in the Marshallese had its usual results, namely, high caries
rate in teen-age children, severe peridontallesions
in adults (heavy calculus and loss of alveolar
bone), and edentulous mouthsin the aged. Radiation exposure did not appearto have affected developing dentition in the exposed children.
Late effects ofradiation. Various parameters usually
associated with aging were measured or estimated
ona Oto 4+ scale (skin looseness, elasticity, and
senile changes; greying of the hair and balding;
accomodation, 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
same age groups showed no apparent differences.
A biological age score was calculated for indiviuals
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 same in the exposed as in the unexposed
people.
The one case of cancer that developed in the exposed group occurred at 5 years after exposure,
too soon, it is believed, to bear any particular relation to radiation exposure. Leukemia surveys in-
cluding physical findings, studies of white cell
ea s
me
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stem =>
status of the people in relation to that of the unexposed comparisop.population, particularly in regard to any possible late developing effects of their
exposure, their hematological status, and the influence of the slightly contaminated environment
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