METHODS
DOSI tETRIC EQUATIONS
Declining continuous uptake of radioactive dietary items was mathematicall
modeled for each nuclide of concern.
The following general equations were
used
ype w
o
X.K
*iti
f, (s
Ce
i K-KE
q-q° (i Xie
E
|
.
1
(e - Qa+Kgt
Xi
1 (2 py
ii
:
Po
=() 4K, et
AD)
-(\+Kp)t
-(A+K, de
E’"
-e
i’)
Ly!
Ap? =
be ERP
,L
UU Ue/fu- a GRe
—-OA+K.)e
i)
(1)
» and
.
_ - (A+Kj)t))
(2)
o£
(Kixke -(A4K;) en (AtKgit + (A+Kg) aw)
Ki-K
1 E
(KU+A)
(K.1 +A)
E
'
+q° =
i
X.
car fire
-(A 4K; et
i
i),
(3)
where
t
= time post onset of uptake, days, .
X
= instantaneous fraction of atoma decaying per unit time, day!
P° = initial atom ingestion rate, atoms day~!,
Kj = instantaneous fraction of atoms removed from compartment i by physiological
mechanisms, day~!,
Xj; = compartment i deposition fraction,
‘
Xs = the number of atoms in compartment i relative to the number in all compart-
ments at the onset of uptake (t=0),
U
= instantaneous urine activity concentration, Bg gol,
U_
= subject urine excretion rate, & day~!,