Values of the parameters in the above equations can be taken from Figures 5
and 6.
The equations for GIT, liver, kidney, and hone are identical to the
ICRP If and Task Group models, but the parameter values are those indicated in
Figure 6. Stuart et al. (1971) did not give estimates for total body.
INHALATION
Modifications to the SDB Model
We (Bloom and Martin, 1976) modified the SDB, long-term model to include
ingestion and the possibility of transfer from the blood to lungs and to lymph
nodes. We also incorporated many of the long-term transfer- of the Task Group
model. However, we also simplified the model somewhat by reruving the variable half-life lung compartment from the SDB model.
The resulting model ts
shown in Figure 7.
In this figure, the Upper Respiratory Tract (URT) refers
to the nasopharyngeal and tracheobroncheal regions, while Deep Lung (DL)
refers to the long-term component of the pulmonary compartment in the Task
Group model.
,
(FAST)
GASTROINTESTINAL
The equations for our modifications to the SDB model are
Terr 7 (Py + Dy + Po) FupcAy*® forc*pi ot * fue*LYLiver + Ht,
UPPER
RESPIRATORY
TRACT
INGESTION
TRACT
(18 HOURS TRANSIT)
(70)
0.003%
FECES
++
10%
Th 7 (Dy + D, + De) foreAn* forratorr + fore pip.
(71)
dypp /dt = (05 + Dy + DefoeA* fponta ~ On * pe) ¥oe
(72)
youn’ 8t = ForepeYpt * fere™a > Cat Ore) rhe
(73)
dyoiyr/9t = foup eri* fonrr*peYor 7 *a¥TLNR
(74)
8¥pver/dt = fertg - On * LD ¥iver
dy/dt = FaxéR - O, + AP) Yy
672
0,85%
OE
(FAST)
al
ue
+ Fedex + ABY gone
dyarwr/?t = fara aLYaLnm ~ “AYALNR
LUNG
(3 YEARS)
BLOOD
71%
+ fore*9L’rine * face acYaLnm * fie*LYLtver
4¥prne/4© = foran*puYon * fpacta 7 a * Xan? YALNM
DEEP
1%
(75)
(76)
90%
1%
a% 7°
|
”
LIVER
KIDNEY:
looz{
|25%
(100 YEARS)
‘
Cunine)
!
'}
We
TIL. --F-~,|
it
1] |
!
MOBILE
1
(2 YEAR)
[yj
te]
( vear)
70%
L}
|
70%
RETAINED
|;
ry
i
fit
',
Biological Half-Time in Total Body is
|
MOBILE
|
1
Fraction From Blood to Total Body fs 100% |
'
KINFINITE)
to
an
|
\
RETAINED
(INFINITE)
1 LYMPH NODES{|
|!
1
t
:
'
1
|
'
!' LYMPH NODES}
ee 4
BLOCK DIAGRAM FOR MODIFICATIONS TO THE SDB MODEL
673
||
|
'
LoL LLL i
FIGURE 7.
3%
if;
'
' —_rrI
i
|
(77)
(78)
3
30%
BONE
(40 YEARS
B. 5%
oT
68%
0.2%
f
i
(40 YEARS)
|