THYROID NODULES ASA LATE SEQUELA OF RADIOACTIVE FALLOUT*
In a Marshall Island Population Exposed in 1954
R. A. Conarp, M.D.,f J. E. Ratu, M.D.,f Pu.D., anp W. W. Sutow, M.D.§
UPTON, LONG ISLAND, NEW YORK
NODULES of the thyroid gland have been discovered during the past three years in a number of people of Rongelap Island who had been
accidentally exposed to radioactive fallout in 1954.
The accident was the result of an unpredicted shift
in winds after the experimental detonation of a
low their return. During the years after the accident, over 200 Rongelap people or their relatives
who had not been exposed to fallout returned to
live with the exposed people, and this group has
formed an excellent comparison population.
deposited on 4 inhabited Marshall Islands to the
east. Inhabitants of Rongelap Atoll, about 100 miles
away, received the largest amount of fallout. The
somatic effects bf this radiation have been well doc-
to be sublethal. Aside from widespread anorexia,
large thermonuclear device at Bikini in the Marshall
Islands, which caused radioactive fallout to be
umented in a number of medical reports and are
summarized elsewhere.'?
‘This report concerns the recent development of
thyroid abnormalities among the 82 people of Ron-
gelap Atoll who received the largest exposure to
fallout radiation. Sixty-four of these people were on
their home island when the detonation occurred.
Eighteen others were fishing on the nearby atoll of
Ailinginae. They saw the blinding flash of the detonation in the early morning, followed by a white,
snow-like fallout throughout that day. The people
on Rongelap Island received the largest exposure:
175 rads of whole-body gamma radiation, thousands
of rads to the skin (largely beta) from deposit of
fallout material on the body and significant amounts
of radionuclides absorbed by inhalation and con-
SUMMARY OF EARLY FINDINGS
The whole-body dose of radiation received proved
nausea and a few cases of vomiting and diarrhea,
along with irritation of the skin occurring during the
first two days, the most notable effect of the exposure
was depression of the blood-forming tissues. Although
the peripheral leukocyte counts were reduced to
about one half to one third of the normal levels and
the platelets to about one third to one eighth of the
normal values during the first five or six weeks, nei-
ther infection nor bleeding clearly related to radia-
tion effects (except possibly menorrhagia in a few
women) was observed. Recovery of peripheral blood
elements was nearly complete by one year but lagged
thereafter; the mean levels remained slightly below
those of the comparison population through ten years
post exposure. However, the survey at eleven years
showed levels of peripheral blood elements that appeared to be about the same in the exposed as in the
sumption of contaminated food and water. The 18
unexposed people.
Radiation lesions (“beta burns”) of the skin and
spotty epilation of the head were widespread, begin-
were evacuated
antecubital fossae and dorsa of the feet. Most of the
people on Ailinginae received less than half the
exposure of the other Rongelap people. Both groups
two days after the accident and
lived in a temporary village on a southern island in
the Marshall group until 1957, when the radioactive
levels had subsided sufficiently on Rongelap to al*From Medical Research Center, Brookhaven National Laboratory.
Research supported by the United States Atomic Energy Commussion and the Trust Territory of the Pacific Islands.
tSenior scientist, Medical Research Center, Brookhaven National
Laboratory, Upton, New York.
tDirector of intramural research, Navonal Institute of Arthritis and
Metabolic Diseases, National Institutes of Health, Bethesda, Maryland.
§Associate pediatrician, Medical Department, University of TexasM.D. Anderson Hospital and Tumor Institute, Houston, Texas.
ning about two weeks after exposure. The most com-
mon sites for the burns were the head, neck, axilla,
lesions were superficial and healed without grossly
visible sequelae. However, some of the lesions were
deeper and resulted in pigment changes and scarring
that have persisted. The hair in all cases regrew in six
months and was normal in color and texture.
Absorption of radionuclides in the fallout from
inhalation and from consumption of contaminated
food and water was detected by radiochemical analyses of urine. The highest body burdens occurred
during the first two days on the Island before they
were evacuated, when they were exposed to an envi-
Reprinted from the New England Journal of Medicine
274: 1392-1399 (June 23),