33
Two deaths occurred in the exposed and onein
the unexposed groupsince the last survey. The
deaths in the exposed group did not appear to be
related to radiation exposure. Diseases, infectious
and noninfectious, were as commonin the exposed
as in the unexposed people. Nutrition appeared
good except for slight hemeralopia in several
children ascribed to vitamin A deficiency. The
birth rate was about the samein the exposed as in
the unexposed group, andthe babies appeared
normal.
Nolate effects of exposure were noted. Shortening of life span has not been observed. The death
rate has been about the samein the exposed as in
the unexposed population. Premature aging of the
irradiated group has not been grossly visible. No
radiation opacities of the lens or differences in
visual acuity have been noted. No malignancies
have been observed, and the incidence of degenerative diseases was about the sameas in the unexposed group examined. Genetic studies have not
been carried out, but no difference in the inci-
dence of congenital abnormalities has been noted
in the first-generation children of the exposed
compared with the unexposed populations.
The only residualeffects of beta irradiation of
the skin were seen in 12 cases which showed vary-
ing degrees of pigment abberation,scarring, and
atrophyat the site of deeper burns. In no case was
there evidence of chronic radiation dermatitis or
premalignant or malignant changein thelesions.
The return of the Rongelapese to their island
(which has a persisting low level of radioactive
contamination)is reflected in a rise in their body
burdens andincreased urinary excretion of certain
radionuclides. Estimates of these body burdens of
radionuclides were determined by gammaspectroscopy and by radiochemical analyses of urine
samples. These estimates showed that the body
burden of Cs'*" had increased by a factor of 100
and of Sr®° by a factor of 10, with someincrease
in Zn* also, since the return to Rongelap. However, the levels were well below the accepted
maximum permissible levels. Analysis of bone
samples on one of the men whodied showed 3.7
Sr®? units/g calcium. Further detailed studies on
the radiation ecological aspects of these surveys,
including examinationsof the food and human
metabolism of these isotopes, is in progress and
will be an importantpart of future investigations.
The survey team devoted considerable attention
to other medical studies in the Marshallese not
directly related to radiation effects but possibly
having some bearing on prognosis. Findings in
these studies were commonto both the exposed
and unexposed populations. An extensive intestinal parasite survey showed that the people
were infected with many types of protozoa and
helminths, although this finding did not entirely
account for the generally higher incidence of
eosinophilia. Among other findings that need
further explanation are the general anemic tendency, the high plasmaprotein levels with increased
gamma globulin, and the high levels of serum
protein-bound iodines and vitamin B,,. It is hoped
that some of these problems will be solved in
future surveys.
Another group of investigations concerned the
anthropological background of the Marshallese
based onstudies of genetically determined traits.
Amongthese were determinations of various blood
groups and of hemoglobin and haptoglobin types.
These studies are shedding some light on the
origin of these people and on the homogeneity of the population being investigated. Their blood
groups resemble most closely those of people from
Southeast Asia and Indonesia, and the population
appears to be relatively homogenous.
Acknowledgments
Because of the broad scope of the studies carried
out in this survey and the complexity of the operation, the cooperation and coordination of many
persons and agencies were necessary to carry out
the mission successfully. The authors are deeply
grateful to many individuals, too numerous to
name,for their invaluable assistance and coopera-
tion.
Manyofficials of the Atomic Energy Commission, particularly Dr. Charles L. Dunham, Dr.
H.D. Bruner, and manyoftheir staff of the Division of Biology and Medicine,as in the past. have
been most helpful in the coordination of arrangements with the Departmentof Defense, Department of the Interior, Department of State, and
other govermental agencies.
At Brookhaven National Laboratory the high
degree of interdepartmental! cooperation made
possible the designing and constructionofthesteel
room, the assembling andtesting of complexelectronic equipment needed for the gammaspectroscopy, andthe ordering, packing, and shipping
of equipmentfor the survey. We are particularly