30
that exposed people neither have aged faster nor
appear older than similarly aged unexposed Marshallese. No doubt the subtle changes which occur
with aging would bedifficult to detect overthis
period of time. During the 4-year survey, data
were collected_in an attempt to obtain semiquantitative estimates of biological age by scoring the
degree of certain criteria such as greying of the
hair, skin looseness, skin retractility, arcus senilis,
retinal arteriosclerosis, accommodation, blood
pressure, etc. These data have not yet been completelv analyzed.
Degenerative diseases**-** have not been found
to be increased in the exposed people. No malignancies 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 Mar-
shallese. (No cases have shown decreasein alkaline
phosphatase of neutrophils, nor have increased
levels of basophils been noted.) Since theincidence of malignancy or leukemia would be expected to be relatively low with the dose ofirradiation received, and since such a small populationis
involved, the probabilities are good that such
effects will not be observed in the Marshallese.
Ophthalmological changes related to late effects
of radiation'*-'* have not been seen. Slit-lamp
observations over the past 4 years have revealed
no polychromatic plaquesor cataracts. Nodifferences were foundin visual acuity in the exposed
and unexposed children.
Genetic effects.°°*'
No specific studies for
genetic effects have been conducted. Ofthe 18
babies born to irradiated parents andliving at
the time of examination, none showed any 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 COMMONTO BOTH EXPOSED
AND UNEXPOSED GROUPS
Certain findings commonto both exposed and
unexposed Rongelap people may havepossible
significancein relation to their state of health and
future prognosis. Clinical laboratory examinations have revealed a complexity offindings diffi-
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% orless 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 examination. The following have been considered as
possible etiological factors:
1) Nutritional deficiency, such as low dietary
proteins or iron deficiency. Althoughthedietis
extremely limited and fish supplemented by small
amounts of other meats are aboutthe only source
of proteins, there is no good evidence that such a
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 ofthe red blood cells. Poor
absorption or deficiency of vitamin B,, is apparently not a factor since the levels of B,; in the
serum were surprisingly 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 showed positive tests in only 10
people. Chronic blood loss from this source does
not seem likely; also, anemia is not usually associ-
ated 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 gammaglobulin
component maybea reflection of such infectious
processes.
The presenceofeosinophilia 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 highin-
cidenceof intestinal parasites might account for
the high eosinophil counts. However, as pointed
out, mostof the types of parasites found are not