INTRODUCTION.
Following the detonation of a thermonuclear device at the Pacific Test Site
on 1 March 1954, 239 Marshallese people were exposed to significant levels of
gamma radiation from fallout.
Estimated total exposures ranged from 175r on
Rongelap to lir on Utirik (1).
These populations were evacuated to Kwajalein for decontamination and care.
During the two days of fallout exposure before evacuation was completed, the
Marshallese also received some radioactive materials internally by ingestion and ~
inhalation.
Estimates of the internal body burden from fallout were obtained
from the analysis (1) of urine samples collected soon after exposure.
These data indicated that the acute hazard from internally deposited fission
fragments was quite small as compared to the whole body gamma radiation exposure.
Although the radioactivity levels in the urine were low, the activity was
sufficient to obtain reasonable precision and to warrant additional long term
studies of the activity levels and excretion patterns of this rather large and
well isolated population.
The people from Alinginae and Utirik were returned to their home islands
in June 1954.
Radiation intensities on Rongelap, however, precluded an early
return to this atoll and the Rongelap people lived on Majuro from June 1954 until
July 1957.
Basic data on the food crops of thejarshallese indicated that after
resettlement on the contaminated atollsintake of strontium? would be increased
considerably, and that cesiun'37, zinc®?, and cobalt©? were dietary constituents
of island and ocean foodstuffs, and also would be assimilated (2).
The expected
increases in the trace amounts of radionuclides in the food supply of a large
population would afford an opportunity to investigate the rate of equilibration
and the discrimination factors operating between food supply and man.
Urinary