METHODS
Body~Burden Data and Urine Activity Concentrations
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 reports (co56, 58,
59, 60, 62, 63, 67, 70, 75 and Wo59) and from recent surveys performed by men~
bers of the Safety and Environmental Protection Division of Brookhaven National
Laboratory.
The methods used to obtain the recent body-burden data were
Presented by Miltenberger (Mi80).
The most recent average data obtained for
adult body burden at Rongelap and Utirik are presented here.
These data were
obtained in April 1978, August 1979 and August 1981.
In the cases of 13766, 6004 and 620 direct body-burden measurements were
made.
In the cases of 905, and 239 py urine activity concentrations were
measured and then converted to body-burden estimates.
toe
:
.
soe
:
This was done by relating
the activity in urine to the activity in the total bedy.
For
90
Sr and
239
Pu
this involved use of derived quantities which are developed in the next section.
Derived Quantities
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.
In
order to select an appropriate model for this relationship, the body-burden his~
tory and the history of activity in vegetation and soil were examined.
concentrations of
137),
8,
129
Activity
I, and 90. in surface soil on Rongelap and Utirik
Atolls were observed to decline with time at a rate greater than radioactive
decay from 1954 to the present (Ne77, Ne79, Br82).
137
Cs and
90
Activity concentrations of
Sr in vegetation were observed to decline at a rate greater than
that predicted by radioactive decay alone (Ne77, Ne79).
Body burdens and urine