Tabte I.
PARAMETER VALUES
Task Group Lung Model Parameter Values
values of f. and T, [3] are
Typical values of Ds D,» and D, and recommended
FRACTION OF INHALED PARTICLES DEPOSITED
(a)
IN THE RESPIRATORY SYSTFM VERSUS PARTICLE DIAMETER
Particle Size
AMAD
Micrometers
given in Table 1.
Fraction of Inhaled Quantity Retained
Nasopharyngeal
Tracheotronchial
Pulmonary
Region, D3
Region, D,
Region, De
0.05
0.1
0.3
0.5
1.0
2.0
5.0
0.001
0.008
0.063
0.13
0.29
0.50
0.77
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.59
0.50
0.36
0.31
0.23
0.17
0.11
classificaTable 3 of Ref. [1] gives the pulmonary clearance
,
For suitable values of fis f5> Th Ty
tion (D,W,Y¥) of inorganic compounds.
M_, and A EEF(RBE)n), see Refs. [3,4,5].
n
GENERAL TREATMENT
by clearance
The subcompartments of the respiratory tract are identified
pathways (K = a,b,...h).
Equations for calculating burden, dose, and dose
commitment for a given subcompartment are as follows:
Burden = a
dQ,
CLEARANCE PARAMETER vatues ©)
=e
=
=
=
Compartment
k
NP
TB
P
L
a
a
=
b
dt
D
qT,
fy
Translocation Class
W
b
b
T..
f.
Ty.
SQ. + MQ = £,D Q/8. if Q, is constant
Y
fy
b
0.01
0.01
0.50
0.01
0.10
0.01
0.40
0.99
c
0.01
0.95
0.01
0.50
0.01
0.01
d
0.20
6.05
0.20
0.50
0.20
0.99
e
0.50
0.80
50
1
50
50
Q.15
0,40
0.40
0.05
500
0.05
i
0.50
1.00
50
1.00
1000
0.90
£
gz
h
= EO
a So
n.a.
Nea.
0.50
0.50
Ta.
n.a.
0.20
0.40
0.90
1
500
500
(a) Estimated from data of Task Group on Lung Dynamics. (9)
0.01
0.40
0.40
0.15
Qe = FPn@y/SE8 + AY?
Q, = (EDI /Ay) (exp Gay t))
(1)
Dose = Dd
t
De = RED aly (L-exp(-A, t) dt
Dd. = (REDQh) (.
1-exp(-A,t) }
ik
(b) As amended by ICRP Publication 19 (2).
D.W.Y. = Days, Weeks, Years
loc, = Clearance pathway (See Figure 1)
ry = Biological half-time (days) for pathway k
fi. = Fraction cleared by pathway k
694
695
(2)