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slightly below the mean control count. The mean
platelet level is about the same as found at one
year after exposure and is still slightly below
the control level.
The mean neutrophile count at
one year after exposure had reached the control level.
The delay in complete recovery of lymphocytes and
platelets is similar to that reported in the two-year
follow-up studies of the Japanese casualties of the
atomic bombings. "tvidence from the Marshallese
experience indicates that the lowered levels of these
blood elements have not lowered the resistance of the
people to disease, and the present levels are not
considered to represent a serious condition.
"Residual changes in the skin from the beta
irradiation continue to show improvement.
Pigment
aberrations are still evident in 15 cases and in four
of these there is also scarring with some adherence
of the skin to the subcutaneous tissue.
However, there
is no gross evidence of tissue breakdown or malignant
change in any of these lesions, and surgical repair is
not considered necessary at this time.
Histological
examination of siin biopsies at sites of radiation
lesions shows residual effects of radiation damage,
but no evidence of pre-malignant or malignant changes.
"Opthalmological survey reveals that there are no
radiation-induced lens opacities, and the incidence of
ocular lesions is similar in exposed and control
populations.
"The radiochemical analysis of the urine of the
Rongelap people shows measurable activity which is
largely due to cerium-144-praseodymium-144 with only
slight activity due to strontium-90,
The body burden
of these isotopes is estimated to be well below the
permissible levels.
"xamination of bone specimens in
the case of the one man who died shows no radiation
that can be definitely associated with fallout
deposition in the bones.
Studies of radiographs of
the femurs of the exnosed children show no evidence
of any bone defects from possible deposits of
radionuclides."
7. External Gamma Dose Rates on Rongelap Atoll.
The
external gamma dose rates at three feet above the ground on
the Island of Rongelap, up to the end of October 1955, are
shown in the attached graph (Annex "A" to Appendix "A").
It
might be expected that this curve will flatten out with time
due to dominance of the 33 year half-life cesium-137.
If the
data on the craph were extrapolated to the time of the last
-6- Department of Ene
pistorian S
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Appendix "A"