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 instituted 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 humanitarlan considerations dictated establishment of a field capability for adminis-

tering 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, and mortality was complicated statistically by a number of problems.
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 incidence of spontaneous abortions, and some children exhibited growth retarda-

tion.

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

from these problems,

discussed

in greater detail

in Section VIII.A.

Aside

the general health of the exposed Marshallese appeared to

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