II.
A.
GENERAL MEDICAL SURVEYS
Background
Following gradual resolution of early radiation effects in exposed
Marshallese, a program for their continuing care and observation was in-
stituted under the aegis of the Atomic Energy Commission.
A medical team,
headquartered at Brookhaven National Laboratory and supplemented by a national
corps of consultants, has continued to implement the program under the auspices of the AEC and its descendant agencies (the Energy Research and Develop-
ment Administration and the Department of Energy) with cooperative support
from the Departments of Defense and Interior (Trust Territory of the Pacific
Islands).
From its inception, the primary objective of the Marshall Islands program was the early detection and treatment of any medical conditions that
might evolve as a consequence of the radiation exposures.
Such an objective
required a longitudinal prospective follow-up study of exposed individuals
along with an appropriate control population.
Both scientific and humanitar-
ian considerations dictated establishment of a field capability for administering periodic primary medical care with some mechanism available for secondary and tertiary referral.
.
In its practical application, several unique problems contributed to the
complexity of this program. As noted in the Introduction, the Marshallese
were exposed to a highly complex spectrum of radiations under source condi-
tions that were unlike any generally experienced in previous radiotherapeutic,
accident, or warfare situations. Dosimetry, therefore, became more a matter of
estimation than precision, especially in regard to specific individuals (2).
Accurate assessment of risks, morbidity,
tically by a number of problems.
and mortality was complicated statis-
The sizes of the exposed populations were
small.
Data on the incidences of various diseases in Micronesia were meager
or non-existent, and vital statistics were unreliable because of the lack of
accurate record keeping in the islands.
It was therefore necessary to include
an unexposed comparison population ("control group") in order to evaluate
better the findings in the exposed populations. Difficulties associated with
these groups are discussed below. In addition to the above problems, geographic, logistic, cultural, and political considerations continually influenced implementation of certain aspects of the program.
In the first decade following the accident, there were few clinical findings that could reasonably be related to radiation (1,13). Cutaneous scarring
and depigmentation were the only residue of beta burns, and no evidence of
skin malignancy appeared.
Exposed Rongelap women may have had an increased in-
cidence of spontaneous abortions,
tion.
and some children exhibited growth retarda-
Peripheral blood elements remained minimally below comparison means for
about five years,
and some chromosomal defects were detected.
In the second decade, the development of hypothyroidism and thyroid
nodules in a significant number of individuals and the occurrence of a fatal
case of acute myelogenous leukemia heralded the possible onset of serious late
irradiation sequelae.
Aspects of these findings have been reported previously
(1,33), and some are discussed in greater detail in Section VIII.A.
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from these problems,
Aside
the general health of the exposed Marshallese appeared to