y+ tay

Sau rele

Brookhaven National Laboratory


Upton, L. L, New York


of Human Beings to Fallout
\iedical Effects of Exposure
Radiation from a Thermonuclear Explosion





The Medien) Besesrcy Contos


wove Mues,



Euvene P. Cronkite, Victor P. Bond, Robert A. Conard

Medical Department. Brookhaven National Laboratory, Upton. New York, USA

Abstract. On March 1, 1954, after detonation of a
thermonuclear device on Bikini atoll, an unexpected
wind shift resulted in the deposition of radioactive
fallout on inhabited atolls. The fallout radiation
caused fleeting systemic effects, dose-dependent
depression of hematopoiesis and skin burns pri-.
marily due to the beta ray componentofthefission
rudionuclides. Within a few weeks, hematopoietic
recovery was substantial but slight depression of
hluod counts was maintained for several years. One
case of fatal acute myeloblastic leukemia developed
ina boy receiving 1.9 Gy as an infant. Cretinism
developed in two boys exposed as infants with estimated thyroidal dose in excess of 50 Gy. Chemical
hy pothyroidism was detected in several persons.
Thyroid adenomas and cancer commenced appearunce ten years after exposure and became a major
long-term medical problem. There have been no late
cifects attributable to the beta burns 40 years after
exposure. Internal contamination from ingestion
and inhalation of radionuclides is detectable. The
doses are comparable to backgroundlevels in the
| .S. There is no detectible decrease in longevity of
the exposed Marshallese compared to an unexposed
Marshallese population.


The Marshall Islands are located in the
castern part of Micronesia a few degrees north
ot the equator. The atolls consist of a ring of
‘ow-TNing coral islands surrounding a lagoon.
The islands are formed on the rims of extinct
‘olcanic craters. The coral sand consists primarily of calcium carbonate and lesser amounts
Correspondence: Dr. Eugene P. Cronkite. Medical
Department, Brookhaven National Laboratory. P.O.
Box 5000, Upton. New York 11973-5000 USA.
Received November 14, 1994; accepted for publation November 14, 1994, ©AlphaMed Press 1066*099/95/$5 00/0


of other minerals. From 1946 until the termination of atmospheric testing in 1958, the
Marshall Islands were used fortesting of nuclear
devices. Testing was done on Bikini atoll and
Enewetak atoll. In addition, the United States
developed the Pacific Missile Range at
Kwajaiein. thus the area was under the control
of the Department of Defense and the Atomic
Energy Commission. Until Operation Castle in
1954, Marshallese populations were removed
from the atolls near the test site during testing.
During Operation Greenhouse 1951, fallout was
detected but not considered a serious health
problem. The Marshallese people were not evacuated from inhabited atolls for Operation Castle.
On March 1, 1954, at 6:30 a.m., a nuclear
device was detonated on Bikini. An unexpected
change in the windstructure distributed fallout
over inhabited areas exposing Marshallese.
American military personnel and Japanese fisherman on board the Lucky Dragon. Details of
the accident and its effect on the Marshallese
were published by Cronkite er ai. [1.2]. The
data are summarized herein.
The intense heat of the detonation incinerated the coral producing calcium oxide in which
fission products were deposited.
The Marshallese lived in buildings appropriate for the tropics with thatched roofof palm
fronds and open sides for ventilation. Fallout
material collected on the palmfronds, the ground,
trees and on individuals that were in the open.
From the wind velocity, arrival time and
decay patterns. isodose lines were constructed
in the downwind region. The fallout occurred
in a cigar shaped pattern. In the westerly direction the 8.00 Gy isodose curve extended about
140 miles. 5.00 Gy about 160 miles. 3.00 Gy
about 190 miles and 2.00 Gy about 220 miles.
The north-south distance for 2 Gy was roughly

STEM CELLS 19953;13(suppl 1):49-57


eo Sogt nah
Pr a a

Key Words. Thermonuclear explosion * Fallout * Humanradiation exposure * Short-term and long-term radiation effects

Select target paragraph3