4
in the exposed group. It is not known whetherthis
findingis 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 accommodation
levels in the Marshallese appeared to be above the
average in the U.S. population.
Dental surveys 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 peridontal lesions
in adults (heavy calculus and loss of alveolar
bone), and edentulous mouthsin the aged. Radiation exposure did not appearto haveaffected developing dentition in the exposed children.
Late effects of radtation. Various parameters usually
associated with aging were measuredorestimated
on a 0 to 4+ scale (skin looseness, elasticity, and
senile changes; greying of the hair and balding;
accommodation, visual acuity, and arcussenilis;
hearing; cariovascular changes including blood
pressure and degrees of peripheral and retinal
arteriosclerosis; neuromuscular function; and
hand strength). Comparison of these measurements in exposed and unexposed individuals of the
same age groups showed no apparent differences.
A biological age score was calculated for individuals
and groupsbvuse 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-
posed group occurred at 5 years after exposure,
too soon,it is believed, to bear any particularrelation to radiation exposure. Leukemia surveys including physical findings, studies of white cell
counts and types, alkaline phosphatasestaining,
and basophil counts of 4000 white cells showed no
evidence of leukemia or leukemic tendency. One
child in the irradiated group had 3% basophils but
no other positive findings. The cardovascular and
arthritis surveys, as well as the general results of the
physical exanmnations, have not shown any apparent increased incidence of degenerative diseases
in the exposed people. No radiation-induced
cataracts have been observed in anyof the exposed
people.
Genetic effects have not been specifically studied
because of the small numberof people involved.
No apparent radiation-induced genetic changes
have been detected on routine physical examination
in the first-generation children of exposed parents.
If the suggestive evidence of increased miscarriages
and stillbirths in the exposed women is true,this
mayrepresent a genetic effect of exposure.
SETA IRRADIATION OF THE SKIN
It was impossible to get an accurate estimate of
the radiation dose to the skin. Beta burns ofthe
skin and epilation appeared about 2 weeksafter
exposure, largely 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 anddry,
scaly desquamation, and wereassociated with
little pain. Rapid healing and repigmentation
followed. Some lesions were deeper, showed wet
desquamation, and were more painful. A few
burns becamesecondarily 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 13° of the people. deeper.
lesions, particularly noted on the dorsum of the
feet, continued to showlack of repigmentation
with varving degrees of scarring and atrophyof
the skin. By 6 vers the onlyresidual 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. 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
change. Spotty epilation on the heads was short
lived, regrowth of hair occurring about 3 months
after exposure and complete regrowth of normal
hair by six months. No further evidence ofepilation has been seen.
An interesting observation was the appearance
of a bluish-brown pigmentation of the semilunar
areas of the fingernails and toenails in about 90%
of the people, beginning about 3 weeks after exposure. By 6 months, this pigmentation had largely
grown out with the nail and had disappeared in
most cases. The cause of this phenomenonhas not
been explained.