Plutonium Biokinetics in Human Body A. Luciani - Kit-Bibliothek - FZK

For the routine application of Model-b in the radiation protection practice, the E(50)
coefficients for a subject of age 40 at the moment of the intake can be assumed as base case
values for two main reasons:
1. The E(50) coefficients are only slightly dependent on the age of the subject;
2. A subject aged forty is representing the mean age of workers.
The main contributions from organs and tissues to the E(50) coefficients for a 40 years
old subject were calculated as well (Table 3.1.16) in terms of organ or tissue equivalent dose,
H T (see Annex). The values are compared with the same values using the ICRP 67 model, in
order to evaluate the effect of the modification in dosimetric terms introduced by the new
model. The equivalent dose to the lung is also given, because it can significantly contribute to
the E(50), particularly in case of absorption type S. No difference in lung equivalent dose is
expected because it just depends on the respiratory tract model. From Table 3.1.16 it can be
seen that Model-b, on average for all the standard scenarios of contamination, predicts higher
equivalent doses for the bone marrow (+35%,) and smaller ones for the bone surfaces and the
liver (–7% and –12%, respectively) than does ICRP 67. The previous considerations relating
to 239 Pu can also be applied to the other Plutonium radioisotopes.
E(50) coefficients for a forty years old subject in case of inhalation and ingestion of
the main Plutonium radioisotopes are finally given in Table 3.1.17 for standard conditions of
exposure. They were partially already published in a recent publication [163]. These
coefficients can be directly applied in the practical radiation protection procedures.
Table 3.1.16 The main contributions from organs and tissues to the E(50) coefficients for a
forty years old subject in term of organ or tissue equivalent dose (H T(50)).
Scenario:
AMAD–Type
or f 1
Inhalation
117
Organ or tissue
Bone Marrow Bone Surfaces Liver Lung
Model-b.
1 µm - M 9.6•10 -5
1 µm - S 1.1•10 -5
5 µm - M 6.6•10 -5
5 µm - S 6.0•10 -6
Ingestion
5•10 -4
1•10 -4
1•10 -5
5.4•10 -7
1.1•10 -7
1.1•10 -8
ICRP67
7.1•10 -5
8.6•10 -6
4.9•10 -5
4.6•10 -6
4.0•10 -7
8.1•10 -8
8.6•10 -9
Model-b.
1.4•10 -3
1.6•10 -4
9.7•10 -4
8.5•10 -5
7.9•10 -6
1.6•10 -6
1.6•10 -7
ICRP67
1.5•10 -3
1.7•10 -4
1.0•10 -3
9.1•10 -5
8.2•10 -6
1.7•10 -6
1.7•10 -7
Model-b.
2.7•10 -4
3.2•10 -5
1.9•10 -4
1.7•10 -5
1.5•10 -6
3.0•10 -7
3.1•10 -8
ICRP67
3.1•10 -4
3.6•10 -5
2.1•10 -4
1.9•10 -5
1.7•10 -6
3.5•10 -8
3.5•10 -8
Model-b.
2.8•10 -5
7.9•10 -5
1.9•10 -5
4.7•10 -5
~0
~0
~0
ICRP67
2.8•10 -5
7.9•10 -5
1.9•10 -5
4.7•10 -5
~0
~0
~0