were still below control levels, but by one year
post-exposure they had returned to thelevel of the
comparison population.
Platelets fell to about 30% of the control values
by the fourth week. By six months they had
reached 70% of the controls; at one year the mean
platelet count was still below that of the conrrol
population butslightly higher than at the sixmonth survey. At two years the platelets, though
still slightly below the control level, showed some
further increase over the one-year level.
The depression of blood elements in the Ailingnae group who received an estimated dose of 69 r
was similar to that in the other group except that
it was less marked. Even thoughthe doseof irradiation received by the Uurik people was quite
iow (about 14 r), a slight depression of platelets
was observed during the first month post-exposure.
Changes in the hematocrit were not remarkable
in any of these groups.
Clintcal observations revealed no disease processes
or symptoms which could be attributed to radiation effects aside from skin lesions, loss of hair, and
early symptoms. The diseases encountered were
no more severe or frequent in the irradiated than
in the nonirradiated population even during the
period of greatest depression of the peripheral
blood elements. Up until the two-year examination no deaths had occurred amongtheirradiated
people. It was difficult to evaluate the effects on
fertility; however, a numberof apparently normal
babies were born and further pregnancies occurred. No opacities of the lens or other eye
changes were found that could be attributed to
irradiation. The height and weight ofthe irradiated children wereslightly less than those of the
unirradiated children of the sameage, but because
of the small numbers of children involved, no
definite statement could be made.
Beta irradiation of the Skin
No accurateestimate of the radiation dose to
the skin could be made. Lesions of the skin and
epilation appeared about two weeks after ex-
posure, largely on parts of the body not covered
by clothing. Most of the lesions were superficial;
thev exhibited pigmentation and dry, scaly desquamation and were associated with little pain.
Rapid healing and repigmentation followed.
Somelesions were deeper, exhibited wet desquamation, and were more painful; a few became
secondarily infected. Repigmentation gradually
took place in most instances, and someofthe healing lesions, particularly on the back of the neck,
developed hyperpigmentation ofa grayish, dusky
color and a thickening of the skin with “orangepeel” appearance. At one year, however,this type
of pigmentation was greatly reduced. Deeper
lesions on the dorsum of the feet continued to
show lack of repigmentation, with scarring in
some cases. At two years post-exposure 15 cases
continued to show residual skin effects largely in
the form of pigment aberrations, and someatrophy and scarring. Histopathologica! studies of the
skin showed changes consistent with radiation
damage. A common finding in acute lesions was
spotty transepidermal damage accompanied by
atrophy and flattening of the rete pegs with areas
of relatively normal skin between. The dermis
was much less affected than the epidermis. Biopsies taken on later surveys showed considerable
improvement but with some persisting changes.*
In no case was there evidence of any premalignant
or malignantchange.
Pigmentation of the semilunar area of the fingernails and toenails was observed in about 90%
of the people about three weeks after exposure. By
six months pigmentation hadlargely grown out
with the nail and had disappeared in mostcases.
internal Irradiation
Radiochemical analysis of numerous urine
samples of the exposed personnel showed some
degree of internal absorption of radioactive materials, probably brought about througheating and
drinking contaminated food and water. Calculations of the body burden of these materials, how-
ever, showed that the concentration was too low
to result in any serious effect. Analysis of urine
samples six monthsafter exposure showedonly
barely detectable radioactivity present in some
cases. At two years radiochemical examination
of pooled urine samples showed Sr*°=0.6 and
Ce'*.Pr'** =7.0 disintegrations per minute per
24-hr sample. (The samples were not analyzed
*In some sections acanthosis, absence of pigmentin the basal
layer, and atrophy and benign dyskeratosis were noted in the
stratum spinosum of the epidermis. Changes noted occasionally
in the dermis consisted of areas of homogenization and increased
density of collagen, alteration in the distribution of mucopoivsaccharide, presence of mucin in areas of degeneration, and capillary dilatation.