250
S.H. COHN
rate. During the next 3 d, Ca-EDTA was administered daily, 1 g/25 lb body
weight administered orally in the form of pills. Complete urine samples
were collected daily during this treatment period and for 5 d thereafter.
Although there were large fluctuations in the daily urinary excretion,
the mean gross f-activity in the urine following EDTA treatment was 2.5
times the pre-treatment level, Only gross B-activity was measured; the
individual radionuclides present were not identified. The oral administration
of the EDTA did significantly increase the fission product excretion rate.
The overall effect on decreasing the body burden in this situation, however,
was small as the excretion rate was very low at this time. From previous
animal studies, it is known that EDTA is most effective in chelating the
rare-earth elements and not effective at all with bone -deposited aikaline
earths, such as strontium. It is therefore probable that the rare-earth body
burden was affected by this treatment.
SUMMARY
The medical study of the Marshallese accidentally exposed to local
fall-out in 1954 is unique in that, along with the study of the Japanese fisher-
men, it provides the only data existing on the metabolism of mixed fission
products in a human population. Early diagnosis of the internal radioactive
contamination was made by radiochemical analysis of the excreta of the
exposed people and by radiochemical analysis of the tissues and excreta of
animals simultaneously exposed. Initially, Sr§9, Ba!4® , 11%! and its shorter-
lived daughters and a numberof rare-earth elements contributed the major
portion of the internal radiation dose.
After a year, the principal radioisotopes were Sr99, Cs137 and Zn®,
Subsequently these radionuclides and, more recently, Co® as well, have
been measured periodically. Since 1958 the y-spectra of a number of
Marshallese have been obtained with a "portable" whole-body counter.
The report discusses the findings of these studies for the past eight
years. The results of an early attempt to alter the rate of removal of the
mixed fission products in the Marshallese with calcium-disodium EDTA
are presented. The metabolism of the radionuclides and their relationship
to levels present in the environment is also discussed.
REFERENCES
[1] CRONKITE, E.P. etal., The effects of ionizing radiation on human beings: A report on the Marshallese
and Americans accidentally exposed to radiation from fallout, AEC-TID 5358 (1956).
[2]
CONARD, R.A. et_al,, Medical survey of Marshallese two years after exposure to fallout radiarion,
J. Amer. Med. Assoc, 164 (1957) 1192.
[3] CONARD, R.A. etal., Effects of fallout radiation on a human population, Rad, Res. Suppl. 1, 1 (1959)
280,
[4] COHN, S.H. etal., Intemal radioactive contamination of human beings accidentally exposed to
radioactive fallout material, NRDL-TR-86 (1955).
{5]
COHN, S.H., CONARD, R.A, and ROBERTSON, J.S., The internal radioactive contamination of a
Pacific Island community exposed to local fallout, Symp. on Radioisotopes in the Biosphere, University
of Minnesota Press (1960).
(6] Van DILLA, M.A., FARMER, G.R. 1nd BOHMAN, V,R., Fallout radioactivity in cattle and its effects,
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