33

Estimation of Body Burden of Sr”
Gammaspectrographic analyses on the Rongelap people in 1961 by whole-body counting in a

21-ton steel room indicated that the mean body

burden of Cs'*? had not shown anysignificant further increase over the 1959 level and that the mean
Zn“* level had been reduced by a factor of about
6. Since these results implied that the body burdens had reached equilibrium with these gamma
emitters in the environment, further gamma spectrographic analysis was deferred, the next being
planned for about 1965, Therefoie the steel room

was not taken to Rongelap onthis survey and no

whole-body gammacounting was done. However,

urine and other samples were coliccted and

brought back for radiochemical analyses,
Srand calcium analyses were carried out on
24-hr urine samples from 27 Rongelap people, 18
in the exposed group and 9 in the unexposed, and
on a 12-liter pooled sample from the population
at large; on vertebra and rib samples (autopsy specimens from the 78-yr-old woman who died in

In view of the uncertainties associated with ex-

trapolation from urinary excretion data to body

burden of Sr, other corroborating evidence has
been derived from analyses of bone samples. Because of the difficulty of obtaining autopsies on
these people, this means of analysis has been very
limited. However, bone samples were obtained
from an autopsy on the 78-yr-old woman who died
this year, and the Sr’’ analysis of ribs and vertebral

specimens showed an average of 15 pC/g Ca, rep-

resenting a body burden of 11.4 myC or about
5.7% of the MPC (see Table 19). This compares
favorably with the estimate of 12.0 muC based on
the 24-hr urine samples. Bone samples from the
autopsy of a 35-yr-old man in 1958 showed a Sr*"
body burden of 2 muC.Theestimated body burden
derived from the 1962 bone samples therefore
shows about a sixfold increase over that from the
1958 samples.
The Srlevels in the coconut crabs in 1962
(Table 19) are close to those previously reported
by Held.'* It is not clear why the crabs continue to
show such high levels, but the ban on their consumption cannotyet belifted.

March 1962); and on 4 coconut crabs. The results

of these analyses are presented in Tables 17, 18,
and 19, The urinary levels of Sr** are somewhat
higher than last year.

Summary

The fluctuations in calcium level in the samples

cause variations in the Srlevel expressed per g
Ca. The pooled urine samples contained 7.2 pC/I
Srin 1961 and 7.9 in 1962 (1 pC = IpyC), but
the calcium levels differed so markedly (141 mg/l
in 1961 and 18 in 1962) that they were not used
in calculating the body burdens of Sr**. In 1962
the meun Sr°° values from the individual adult 24hr samples were 12.45+1.30 pC/Il or 114414
pC/g Ca. From these values, on the basis of previous calculations,’* the body burden was estimated as 12.0 muC. This is about 6.0% of the
maximum permissible concentration (MPC) of
Sr°? (200 muC) for nonindustrial populations, and
represents about 49% of the previously estimated**
equilibrium value of 23 mzC.
Thus the return of the Rongelap people to their
homeisland has been reflected in annual increases
in estimated body burdens of Sr** based on urinary
excretion values. The estimates, in myC, have increased as follows: 2.0 in 1958, 6.0 in 1959, 6.9 in

1961, and 12.0 in 1962. It is not clear why the
ercater increase occurred during the past year.

Medical examinations were carried out in
March 1962 on the people of Rongclap Island, 8
years after accidental exposure to fallout irradiation. The medical team consisted of 15 physicians and mcdical technicians, 9 from the U.S. and
6 from the Department of Public Health of the
Trust Territory of the Pacific Islands. Examinations were carried out principally at Ronvgela;
Island, but some Rongelapese who had moved
away were cxamined at Kwajalein and Majuro

Islands. A total of 308 people were examined, 80
in the exposed group, 37 children of exposed parents, and 191 unexposed Rongelap people who
serve as a comparison population. The Trust Territory ship, Ran Anim, was used to transport the
medical team and equipment from Kwajalein to
Rongelap and return. The team lived in a tent at
Rongelap Village during the survey.
The examinations were carried out with complete cooperation of the Rongelup people, and it
was believed that the presence of the team living

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