SLIDE 53
Body burden history at Rongelap and Utirik.
Adult average body~burden data
and urine-activity concentration data were used as input quantities to
equations which related them to activity intake rates.
These input data were
obtained from Conard's medical report (Co56, Co58, Co59, Co60, Co62, Co63,
Co67, Co70, Co75, Wo59) and from recent surveys performed by members of the
BNL Safety and Environmental Protection Division.
An equation was developed to relate the activity in the urine or whole
body to the activity taken in by ingestion of contaminated food and fluids.
To select an appropriate model for this relationship, we examined the bodyburden history and fhe highgry of ggtivity in vegetation and soil.
Activity
concentrations of
Cs,
I and
Sr in surface soil on Rongelap and Utirik
Atolls were observed by us to decline with time at a rate greater than
radioactive decay #59™ 1954 §8 the present (Ne77, Ne79, Br82).
concentrations of
Cs and
Activity
Sr in vegetation were observed to decline at a
rate greater than that predicted by radioactive decay alone (Ne77, Ne79).
Body burdens and urine activity concentrations were observed to increase
rapidly and to decline slowly throughout the residence time of persons at
Rongelap and Utirik Atolls (Co75, Le80b). These observations led to the
selection of a declining continuous intake model.
The lines fitting the declining continuous intake model at Rongelap are
presented here.
Measured results are plotted.
The body burdens at Utirik
were a factor of 2.6 times less than those at Rongelap for the period 1958 to
1984,
—--—0o Fe-55
—-—e
Cs_137
RONGELAP
----- + Zn-65
BODY BURDEN, nCi
—-——4 Co-60
a Sr-90
s
@
=
ry)
fay
ae
a
[oa]
a
ro}
.?)
a
TIME PAST REHABITATION, days
51