CHAPTER 1
INTRODUCTION
1.1
OBJECTIVES
The present medical resurvey was organized as the first of a contemplated series designed to provide long-term medical examinations of the Marshallese people exposed to radia-
tion from fallout during Operation CASTLE.
1.2
BACKGROUND
Following the detonation of a thermonuclear device on Bikini Atoll on 1 March, 1954, 28
Americans on Rongerik Atoll and 239 Marshallese (64 on Rongelap, 18 on Ailinginae, and 157
on Utirik) were exposed to significant amounts of radiation from fallout. These individuals
were evacuated to Kwajalein, where they were cared for during the acute period following exposure by a special medical team composed of individuals from the Naval Medical Research
Institute (NMRI) in Bethesda and in the U.S. Naval Radiological Defense Laboratory (NRDL) in
San Francisco. A report of medical findings has been issued as an Operation CASTLEreport.!
The present report is concerned with the medical status 6 months later of the Marshallese
people who received the highest estimated dose of gammaradiation, the Rongelap and Ailinginae
groups.*
The Rongelap group was exposed to an estimated 175 r of gamma radiation, calculated
from dose rates measured free in air, over a period of approximately 46 hr. The Ailinginae
group received an estimated 69 r of gammaradiation over approximately 54 hr. Both groups
received additional beta radiation to exposed skin areas. All findings were more severe in the
Rongelap than in the Ailinginae group. These findings are reviewed later in the report.
Because of the continuing hazard from radiation on their homeatolls, the Rongelap and
Ailinginae people were not returned to their homes after observation at Kwajalein. Instead,
they were moved to Majuro Atoll, the Trust Territory Headquarters for the Marshall Islands.
Housing was furnished them on Ijij Island (pronounced “edgit”), 10 minutes by boat from the
Trust Territory Headquarters, where they were residing at the time of the present examinations.
*The Utirik people, who received comparatively slight exposure, were returned to their
homeatoll following observation at Kwajalein and were not examined during the present resurvey. The exposed Americans had been returned to their duty stations in the United States.