71
in adults and 22 nCi in children, about 6 and 11%
respectively of the maximum permissiblelifetime
body-burden levels for the population at large, ie.,
local nuclear testing program and also from worldwide fallout, and to be concentrated by marine
life, particularly fish. The estimated body burdens
for the Marshallese tested (Table 43) are higher
than those found for Japanese bombsurvivors and
“othe ICRP value.!®® Analyses of bone samples
from several autopsies during the past 20 years
gave estimated 9°Sr body burdenssimular to those
obtained from urinalysis (see Figure 37). 137Cs
body burdens also reached their peak in about
1965, at nearly 0.7 pCi (23% of the permissible
level for the general population). The body burdensof the Utirik people were considerably below
those of the Rongelapese. Table 42 showsthat the
estimated bone marrow doses of Rongelap people
of the maximum permissible levels for non-occupationally exposed individuals estimated with the
total body as the critical organ. The values are
slightly higher in females than in males, andsignificantly higher in older persons. *5Fe emits photons of very low energy, and, sinceit is incorporated
into the hemoglobin ofthe red cells, ic results in
reduced by 1974, and presents data also for Uunk
blood samples from the 1974 surveyare also being
analyzed for 95Fe.
from internal and external sources (both natural
and man-maderadioactivity) were considerably
and Bikini.*
The coconut crab was banned from thediet on
Rongelap becauseofits high level of radioactivity,
but about 2 years ago the ban waslifted on the
southern islands of the atoll because the radioactivity had decreased sufficiently (see Table 40).
B. °5Fe BODY BURDENS IN RONGELAPESE
In 1971 blood samples from 62 Rongelapresidents were analvyzed** for °°Fe, and their body
burdens were estimated by the method of Beasley
et al.170 55Fe was known to be present in the Marshall Islandsin fairly high levels as a result of the
*Mr. R. Fairchild at BNL calculated the bone marrow dose
for the 1974 data.
**The °°Fe analyses were carried out by T.M. Beaslev and
E.E. Held at the University of Washington Schoolof Fisheries,
Seattle.
Table 43
Average Body Burdens of 55Fe in Rongelapese, 1971170
Males
Age
No.of
samples
16-20
21-31
32-42
43-53
8
4
5
2
>64
3
54-64
Females
16-20
21-31
32-42
43-53
54-64
>64
6
6
212
5
7
2
2
Body burden,
pCi
0.31
0.33
0.52
0.58
0.53
0.48
0.23
0.34
0.33
0.66
0.57
0.66
for others tested, but they are not more than “00
relatively little irradiation of nucleated cells. Some
C. PERSONNEL MONITORING AT BIKINI
In 1946, before Operation Crossroads, theresidents were evacuated from Bikini. After stays at
Rongerik and at Kwajalein which proved unsatisfactory, they were relocated on Kili Island in the
southern Marshalls, which also proved unsatisfactory. The Eniwetok people were relocated at
Ujelang Atoll, to the west, after their evacuation.
After the 1958 moratorium on atmospheric nuclear testing, numerous radiological surveys were
done on Bikini and later on Eniwetok Atoll.17!-174
In 1967 the principal isotopes contributing to the
gammaradiation field on Bikini and Eneu Islands
were 137s, 69Co, 125Sb, and !55Eu; slight amounts
of Pu werealso found. Considerable variation was
seen in the contamination of individualislands
comprising theatolls of Bikini and Eniwetok since
different tests had been conducted on various ones.
The contamination of Rongelap and Utirik was
more uniform, being due largely to fallout from a
single detonation, Bravo.
In 1968 an ad hoc committee reviewed the survey results for Bikini and decided that Eneu and
Bikini Islands were safe for habitation, with cer-
tain measures recommendedto reduce exposure
(see Appendix 13). In 1969 about 30 people started
work on Bikini Atoll (living on Eneu), and in 1971
several Bikini families moved back to Bikini Island
itself, which now has about 50 Bikini people plus
a few administrators and construction workers.
Annual monitoring of personnel has been carried
out since 1969. In 1974 radiochemical analyses
were done on urine (see Table 37 and Appendix
12) and other samples, whole-body gamma spectroscopy was carried out on personnelliving on