Concept explainers
The absorbed dose to the lung during 13-week period and during the 1-year period immediately following inhalation.
Answer to Problem 11.1P
In 13 weeks absorbed dose is
Explanation of Solution
Given:
Mean radioactivity concentration,
Formula used The effective half-life
The effective clearance rate constant for these particles is
The cumulated activity for all four compartments after
The dose from the activity in the lung is given
Calculation:
Since no particle size is given, the ICRP default value of
The inhaled activity:
The elimination constant for each of the compartments is calculated next.
ICRP 26 give the following depositions of
AMAD particles:
Deposition | Fraction in lungs | Total activity | Activity in lungs | |
N.P. | 30% | 0 |
| 0 |
T.B. |
| 0.08 |
|
|
P |
| 0.25 |
|
|
Total deposited in lung |
|
The effective clearance rate constant for these particles is
For 60 percent of the particles deposited in the P region , whose biological half --life
The effective half-life
Using ICRP 26 for following deposition of inhaled
Region | % cleared | As(0), Bq |
|
|
|
TB | 50 |
|
|
| 69.3 |
TB. | 50 |
|
|
| 3.47 |
P | 40 |
|
|
| 0.693 |
P | 60 |
| 50 | 32 | 0.022 |
The cumulated activity for all four compartments after
The cumulated activity for all four compartments after
Sulfur 35 emits a single beta whose mean energy is
Therefore
The dose from the activity in the lung is given
And,
Conclusion:
The absorbed dose in 13 weeks is
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