750
HARDY, RIVERA, AND CONARD
the high-activity food. Only a small increase in urinary "Sr excretion
was observed, and both fecal and urinary elimination rates fell off
sharply within 10 days after the acute-ingestion period. By 180 days
both urinary and fecal excretion of Sr had dropped to pre—high-intake
levels.
Through integration of the smoothed excretion-rate curves, the
amounts of '""Cs and Sr excreted per 10-day interval were determined.
Excretions during the 7-day acute-ingestion period and the first 10
days after the high-activity-food consumption terminated were summed
over the entire 17-day period. With the assumption that the increase
in the ‘°"Cs excretion rate of the subject was proportional to the increase in the normal body burdens of laboratory personnel, a back-
ground correction was determined and applied to each 10-day excre-
tion value. Since the "Sr excretion rate returned to preexperiment
levels toward the end of the study, it was assumed that any increase
in the excretion rate due to an increase in the normal “Sr diet level
was not measurable. Therefore only the preexperiment Sr level was
subtracted.
The background-corrected cumulative excretions expressed as
percent of intake are plotted against timein Figs. 3 and 4. Fifty percent
of the '*"Cs ingested via the Rongelap food had been excreted in urine
after 85 days, whereas only 14% had been excreted in feces during the
same time. In contrast, almost 50% of the Sr dose had been excreted
in feces at 10 days, whereas only 2.5% had been eliminated in urine.
80
Toro
ot
Poy
ToT
P
pt
tbe
ft
Pb
CUMULATIVE EXCRETED "cs, %
70
4
60 |-
URINE
7
50 --
4
40 f-
4
30 -
4
20 |-
old
0
FECES
tp pd
20
40
ty
60
80
100
=61200«=6140—
DAYS AFTER INGESTION
‘160
180
200
Fig. 3—Cumulative urinary and fecal excretions of "Cs following in-
gestion of Rongelap food.