FALLOUT FROM NUCLEAR WEAPONS TESTS
1333
rete of Cst37 should nave resulted in an equilibrated csi3? burden, with an
estimated daily intake of about 15€0 uuc of Cet3?
Unfortunately no systezatic
gurvey of foodstuffs grown on these atolls has been reported.
Bee ep eo
«
hovever
Data available,
show that coconut frown on Ronselep contained about 9 uuc Ca
gram, and arrowroot (Utirik) contained about 8 uuc C3137 per gran.
137 per
The daily
intake of several hundred grems of either staple would be sufficient to account
for the 1957 excretion level in the Utirik group.
r
a
¢
i]
f.
a
Be
The Rongelap groups had been resettled for about nine months at the time
of the March 195@ medical survey, and urinary excretion levels of cs!3? nee
increased about one hundred fold over 1937 levels.
Mean body burden for the
two groups at this time was 0.9 uc (+ 27 percent) and 1 2 uc (+ 47 percent)
(Tables 3 and 4)
Cestum? 3? body burden may have equilibrated by late 1958 and
predicted burdens were about 1.3 and 1.6 ue respectively
Strontium?” Excretion Levels and Body Burden
Urinary excretion levels of strontium’? are presented in Tables 1,
S
&
2, end 3.
The strontiun?? excretion level in 195C¢ was 0.5 uuc/liter as determined in a
4
Boo
pooled sample of 57 liters
2.
years following fallout exposure.
*
8
the data for the various age groups at early times, mean values for all groups
‘
a
%
gt
BO
of
'
Figure 2 shows the excretion of gr2° for the three
Although there is considerable variation in
Plotted suggest thet the excretion pattern can be expressed conveniently as the
sun of two exponential terms
The lerger portion of gr? was excreted with a
half time of about 4O days, and a smail fraction, 20 percent, vas excreted with a
helf time of about 560 dpys.
This is similar to Cowan's (7) urinary excretion
study of an accident case involving inhaled gr0,
-
As was noted in the March 1958 Ca
137
512°
levels, the excretion levels of S
were also increased to 3.5-4 0/6.2, or about 20 fold
Since ce!37 levels in-
creased 300 - 570 /3h, cr about lho fold, the ratio is about seven in favor of
a
STTEte,
aN iE aany
a]
With the increases in urinary gro excretion levels in 1958, it was
et ll
cestuat 3"
900 1108