that exposed people neither have aged faster nor
appearolder than similarly aged unexposed Marshallese. No doubt the subtle changes which occur
with aging would be difficult to detect overthis
period of time. During the 4-year survey, data
were collected in an attempt to obtain semiquanti-

tative estimates of biological age by scoring the
degree of certain criteria such as greving of the

hair, skin looseness, skin retractility, arcus senilis,
retinal arteriosclerosis, accommodation, blood
pressure, etc. These data have not yet been completely analyzed.
Degenerative diseases’'-*° have not been found
to be increased in the exposed people. No malig-

nancies have been detected. In the irradiated
Japanese an increased incidence of leukemia has
been noted.""-** There have been no cases of
leukemia or leukemia tendency noted in the Marshallese. (No cases have showndecreasein alkaline

phosphatase of neutrophils, nor have increased
levels of basophils been noted.) Since the inci-

dence of malignancy or leukemia would be ex-

pected to be relatively low with the doseof irradiation received, and since such a small population is
involved, the probabilities are good that such
effects will not be observed in the Marshallese.

Ophthalmological changesrelated to late effects
of radiation’*"'® have not been seen. Slit-lamp

observations over the past 4 years have revealed
no polychromatic plaques or cataracts. Nodifferences were foundin visual acuity in the exposed
and unexposed children.
Genetic effects.°°°'
No specific studies for
genetic effects have been conducted. Of the 18
babies born to irradiated parents and living at
the time of examination, none showedany abnor-

malities. In view of the generally negative findings

in the studies of the first-generation offspring of

the irradiated Japanese,”it is unlikely that genetic
studies in this group will be fruitful.
Beta irradiation. Nolate effects of beta irradiation of the skin such as chronic dermatitis or premalignant changes have been found in the Marshallese.
FINDINGS COMMON TO BOTH EXPOSED
AND UNEXPOSED GROUPS

Certain findings commonto both exposed and
unexposed Rongelap people may havepossible

significance in relation to their state of health and

future prognosis. Clinical laboratory examina-

tions have revealed a complexity of findings diff-

cult to evaluate. Principal among these is the
anemic tendency in the population at large.
Hematocrit values of 38% or less were found in

54% of the men, and of 36% or less in 78% of the

women. Also possibly related to this finding was

the increase in reticulocyte counts (>>3%) in about
20% of the people noted during the 3-year exami-

nation. The following have been considered as
possible etiological factors:
1) Nutritional deficiency, such as lowdietary

proteinsor iron deficiency. Althoughthedietis
extremely limited and fish supplemented by small
amountsof other meats are about the onlysource
of proteins, there is no good evidence that sucha
deficiency exists. In fact the blood proteins are
high (average 7.8 g%). It is not known whether
the diet is deficient in iron. Blood smear examinations did not reveal any obvious microcytosis of
red cells. The nature of the anemic tendencywill
be further investigated in the next survey by
carrying out serum iron determinations and running Price-Jones curves of the red blood cells. Poor
absorption or deficiency of vitamin B,, is apparently not a factor since the levels of B,. in the
serum weresurprisingly high. (Experience with
Diphyllobothrium latum infestation suggests that
parasitism of the gastrointestinal tract should be
associated with low vitamin B,, serum concentra-

tions.) The relatively high values of serum vitamin
B,. are puzzling, and no immediate explanation
is apparent.

2) Intestinal parasitism is very prevalent, 72% of
the people showing stools positive for ova and
parasites. However, examination ofthese stools
for occult blood showedpositive tests in only 10
people. Chronic bloodloss from this source does
not seem likely; also, anemiais not usually associated with the parasites found in these people.
3) Chronic infections, particularly skin diseases
and dental caries, may play an etiologicalrole in
the production of the anemic tendency. The high
plasmaprotein levels with high gamma globulin
component maybea reflection of such infectious
processes.
The presence of eosinophilia in the population
is another puzzling problem. (Abouthalf the people show eosinophils >5% in their differential
counts with quite a few values as high as 20 and
25%.) Offhand, it might seem that the highincidenceof intestinal parasites might accountfor
the high eosinophil counts. However, as pointed
out, most of the types of parasites found are not

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