Biomedical Engineering Reference
In-Depth Information
conveys an idea of the detailed nature of the model. It also shows the relationship
to the N-P, T-B, and P regions from the ICRP-30 model. Clearance and absorption
compete in each compartment with time-dependent rates in the revised model.
Breathing rates, volumes, and other parameters have been revised. The default
particle-size AMAD is increased from 1
µ
mto5
µ
m. The revised model allows
dose calculations for specific target regions containing cells that are considered
to be susceptible to cancer induction, in contrast to the mean dose furnished by
ICRP-30. The methodology can be applied to males and females, young and old.
Effects of smoking and other inhaled pollutants can be included.
16.6
ICRP-30 Dosimetric Model for the Gastrointestinal Tract
The ICRP dosimetric model for the GI tract is shown in Fig. 16.8. Each of the four
sections consists of a single compartment: the stomach (ST), small intestine (SI),
upper large intestine (ULI), and lower large intestine (LLI). There are two pathways
out of the SI. One leads to the ULI and the other to the body fluids, the only route
Fig. 16.8
Dosimetric model for the gastrointestinal system.
Table gives masses of the sections and their contents and
clearance-rate data. [Reprinted with permission from
Annals of
the ICRP
, Vol. 2, No. 3/4, ICRP Publ. 30, Part I, p. 33,
International Commission on Radiological Protection, Sutton,
England (1979). Copyright 1979 by ICRP.]
