Introduction to Health Physics: Fourth Edition - Ruang Baca FMIPA UB

RADIATION SAFETY GUIDES 379
Figure 8-12. Fractional deposition in each region of the respiratory tract of a reference nose-breathing worker
as functions of (A). activity median thermodynamic diameter, AMTD, and (B). the activity median aerodynamic
diameter, AMAD. Deposition is expressed as a fraction of the activity present in the volume of inspired air, and
the radioactive particles sizes are log-normally distributed. The particles’ specific gravity is 3 and the shape factor
is 1.5. Abbreviations: AI, alveolar-interstitial; bb, bronchiolar; ET, extrathoracic; BB, bronchial. (Reproduced with
permission from ICRP Publication 66: Human Respiratory Tract Model for Radiological Protection. Ann ICRP. 1994;
24(1–3). Copyright c○ 1994 International Commission on Radiological Protection.)
For modeling purposes, the numerical values for the size-dependent parameter
fs in Table 8-12 is given for two categories of aerodynamic diameter, dae:
0.5 ρ
if dae ≤ 2.5 μm,
χ
then fs = 0.5.
0.5 ρ
if dae > 2.5 μm,
χ
χ
then fs = 0.5 exp −0.63 dae − 2.5 .
ρ
TABLE 8-11. Regional Deposition of 5-μm and 1-μm AMAD Aerosols in Two Persons
REGION WORKER, 5 μm (%) ADULT MALE, 1 μm (%)
ET1 33.9 16.5
ET2 39.9 21.1
BB 1.8 (33%in BB2) 1.2 (47% in BB2)
bb 1.1 (40% in bb2) 1.7 (49% in bb2)
AI 5.3 11.7
Total 82.0 51.2
Abbreviations: ET, extrathoracic; BB, bronchial; bb, bronchiolar; AI, alveolar-interstitial.
Reproduced with permission from Guide for the Practical Application of the ICRP Human Respiratory Tract Model,
Supporting Guidance 3. Ann ICRP. 2002; 32(1,2). Copyright c○ 2002 International Commission on Radiological Protection.