"cs AND “Sr RETENTION FROM RONGELAP FOODS
BO
TTT To
CUMULATIVE EXCE+% ETED P51, SS
70
FECES
a
60—
+
50 F
—
so
-
|
|
0
751
URINE
20
40
po
reef et tt
60
80
100, 120 140 160
180
DAYS AFTER INGESTION
Fig. {—Cuinulative urinary and fecal excretions of Srv foilowingin-
gestion af Rougelap food,
Since the integration limits were relatively large initially compared to
the rate of change of excretion level, the cumulative curves were not
extrapolated beyond the point at 10 days after termination of the high-
activity-food consumption. The urinary to fecal "Cs excretion razi
averaged 3.5, ranging between 2.8 and 3.8, and the “Sr excretion rati
averaged 0,06, ranging between 0.05 and 0.07.
The
cumulative excretion data were substracted from the total
intake to obtain the amount of each radionuclide retained. These re-
sults along with the BNL whole-body '’Cs measuremenis are given in
Tabie 3. When the two sets of "Cs data are compared, they appear io
be in reasonably good agreement with each other. The fact that the
whole-body measurements are the more accurate, however, is seen
from the semilog plot in Fig. 5, The expected single exponential fit
demonstrates that the 7Cs from Rongelap food behaves ina similar
metabolic manner to that observed under other intake tonditions.27""
The deviations from a single exponential function of the retention data
as derived frorm excretion measurements may be attributed to inaccuracies in the eStimation of the contributions from the normal dietary
intake and the accumulation of errors inherent in the procedure. The
niological half-life as measured by the whole-body counter is 74 days,
waereas the apoarent half-life as measured on the initial straight-line
portion of the excretion-data curve is 64 days. When it is considered
that the excretion data underestimate the retention slightly in the early
stagesof measurement, the agreement is not unreasonable. it should be
aointed out that the short-lived (one to two days) componentthat has