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

392 CHAPTER 8
AF(T←S) is the fraction of the energy emitted from the source S by the target
tissue T (from Table 8-17, which is abstracted from Tables H.1 to H.5,
ICRP 66),
m is the mass of the target tissue (Table 8-14 from Table 5, ICRP 66), and
w T is the tissue weighting factor (from Table 8-14).
Using the disintegration data from Table 8-15, the values of AF(T←S) from
Table 8-17, the tissue weighting factor, w T, from Table 8-3 and tissue mass, m, from
Table 8-13, we can calculate the dose to each region. For example, for the basal cells
in the BB region, we have
COMPARTMENT NC, DISINTEGRATIONS AF(T←S)C
BB1 604 0.0508
BB2 16,956 0.0542
BBseq 1,072 0.0985
AI 4,647,546 0
Ē = 0.0498 MeV,
w T = 0.1665 (= 1/2 of 0.333), and
m = 0.00043 kg.
We obtain the dose to the basal cells in the BB region by summing the contributions
from each of the compartments
H(BB)bas =
E Mev
dis × 1.6 × 10−13 J
MeV × w T × w R
m kg × 1 J/kg
Gy
Sv
Gy
× NC dis × AF(T ← S)C, (8.37)
Substituting the respective values from the table above, we calculate
H(BB) bas = 3.256 × 10 −9 Sv.
In a similar manner, we can calculate the doses to the other cells in the lung, the
secretory cells in the BB region and in the bb region, then add the respective doses
to obtain the dose to the lung. The data for making these calculations, as well as the
data for the BB basal cells (which are calculated above), are listed in Table 8-19.
The weighted sum of all the doses to the various parts of the lung is the dose
to the lung from the inhalation, by an adult male, of 1 Bq of 14 C tagged tungsten
carbide, WC, (type S) whose AMAD is 5 μm, is 2.8 × 10 −8 Sv. Doses to other organs
depend on the fate of the activity transferred to the blood. When calculating the
EDE from this inhalation, the lung dose must be multiplied by the weighting factor
for the lung, 0.12.
Gases and Vapors. Inhaled gases either dissolve in the fluids of the airway surfaces
and are “deposited” there, or are exhaled. Those gases that dissolve may interact