56
status of the people in relation to that of the unexposed comparison population, particularly in regard to any possible late developingeffects of their
exposure, their hematological status, and theinfluence of the slightly contaminated environment
on the assimilation, excretion, and body burden of
radionuclides.
Medical histories of the intervals between the ex-
aminations 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 epidemic on Kwajalein.
The four deaths that have occurred in the ex-
posed 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 ofthe birth
rate of the exposed group over the past 6 years
seemsto indicate no noticeable effect of their expo-
sure 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 somewhatgreater incidence of miscarriages and stillbirths
has been noted in the exposed women, butbe-
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 U.S. population.
A dental survey showed nosignificant differences
in either caries rate or incidence of peridontal disease between exposed and unexposed groups. The
poor ora} 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 haveaffected de-
cause of the paucity of vital statistics in the Marshallese and the small numberof people involved,
the data are not readily amenableto statistical
veloping dentition in the exposed children.
Physical examinations showed the exposed and the
unexposed people to be generally in a state of good
health. No diseases were noted that could be
senile changes; greying of the hair and balding;
analysis.
directly related to radiation effects. The incidence
Late effects ofradiation. Various parameters usually
associated with aging were measuredor estimated
on a 0 to 44 scale (skin looseness, elasticity, and
accomodation, visual acuity, and arcussenilis;
hearing; cardiovascular changes including blood
pressure and degrees of peripheral and retinal
of various disorders in both adults and children
wasaboutthe samein the exposed and unexposed
groups.
arteriosclerosis; neuromuscular function; and
a project on the verification of accuracyofages of
A biological age score was calculated for indiviuals
fore, the suggestive evidence previously presented
of possible lag in statural growth in the exposed
Life shortening effects of radiation have not been
In connection with growth and development studies,
the children has not been completed and, there-
children must await confirmation. It was noted,
however, that in the 6-year chronological age
group, three boys and onegirl outof five boys and
twogirls in the exposed group exhibited signifi-
cantly retarded skeletal maturation as judged by
x-ray examination. The birth dates of these children seemed to befairly well established.
cr
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 is noted in
people in the continental United States.
Anarthritis survey showed no great differences between the exposed and the unexposed people, and
about the sameincidenceasis seen,in American
populations.
Anophthalmological survey showed no remarkable
differences between the exposed and unexposed
groups except possibly a slightly greater number
hand strength). Comparison of these measurements in exposed and unexposed individuals of the
same age groups showed no apparentdifferences.
and groupsby use of an average percentagescore.
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 particularrelation to radiation exposure. Leukemia surveys in-
cluding physical findings, studies of white cell