What annual effective dose equivalent to the lungs would you receive from 210Po by
smoking one pack of cigarettes per day? Calculate this first analytically; then modify the
Stella lung model provided to perform the same calculation and compare. Define any
assumptions you make. The activity inhaled per pack is 123 mBq. (20 pts)
2. As you probably know, natural potassium, which we consume every day, contains small
amounts of 40K. Assume you have the following breakfast: a few dried apricots, a banana,
a glass of orange juice, and a bowl of bran flakes. Then for lunch, you consume a glass of
skim milk, a medium potato, a pinch of potassium chloride as a salt substitute and a 3 oz.
chicken breast.
Each of the following contains the stated activity of 40K:
a few dried apricots 409 pCi
a fresh banana 368 pCi
a glass of orange juice 409 pCi
a bowl of bran flakes 155 pCi
a glass of skim milk 285 pCi
a medium potato 690 pCi
a pinch of salt substitute 499 pCi
3 oz. chicken breast 180 pCi
a. Based on your breakfast and lunch menu, the intake data above, and referencing ICRP
30 and 38 for any parameters you need, determine your 40K committed effective dose
from ingestion. (20 pts)
b. Now assume that the same activity of 40K was inhaled. Using ICRP 38 as a reference, and
defining any assumptions you make, analytically calculate your committed effective
dose. Then construct a STELLA model to determine the integrated activity in your body
(nt) as a function of time and estimate your committed effective dose (again, state any
assumptions you’ve made). (20 pts)
c. Finally, use your results to estimate an ingestion ALI, and the inhalation ALI and DAC for
40K. Compare those values with what’s published in the metabolic data. (20 pts)
To calculate the annual effective dose equivalent received from 210Po by smoking one pack of cigarettes per day, we first need to understand the relevant parameters and equations.
1. Analytical Calculation:
The effective dose equivalent can be calculated using the following formula:
Annual Effective Dose Equivalent (mSv/y) = Inhaled Activity (Bq/y) x Dose Coefficient (Sv/Bq)
Here, the inhaled activity from one pack of cigarettes is given as 123 mBq and the dose coefficient needs to be determined. The dose coefficient for 210Po can be found in publications such as the International Commission on Radiological Protection (ICRP) reports or other authoritative sources.
2. Stella Lung Model:
To modify the Stella lung model to perform the same calculation, we would need the Stella model and access to the relevant parameters associated with 210Po inhalation. By inputting the inhaled activity and using appropriate modeling methods, the Stella model can estimate the dose received.
Assumptions for both calculations:
- The smoking of one pack per day is consistent throughout the year.
- The dose coefficient used is accurate and up-to-date.
- No other sources of 210Po exposure are considered.
Moving on to the second part of the question:
a. To determine the 40K committed effective dose from ingestion, we need to calculate the intake of 40K from the given food items and use relevant dose coefficients.
The committed effective dose from ingestion can be calculated using the formula:
Committed Effective Dose (Sv) = Ingestion Activity (Bq) x Dose Coefficient (Sv/Bq)
Using the provided 40K activity values and respective food items, sum up the total ingestion activity and multiply it by the dose coefficient for 40K.
b. To calculate the committed effective dose from inhalation of 40K, we need to use the appropriate dose coefficients for inhaled 40K. Similar to the previous case, the dose coefficients can be found in ICRP reports or other authoritative sources.
Using the same formula as before, the committed effective dose from inhalation can be calculated by multiplying the inhaled activity by the dose coefficient for 40K.
To construct a Stella model, we would need access to the model itself and the parameters related to 40K inhalation. By inputting the inhaled activity and using the appropriate modeling methods, the Stella model can estimate the dose received over time.
Assumptions for the inhalation calculation:
- The activity values for inhaled 40K are accurate.
- The respiratory parameters used in the Stella model (e.g., breathing rate, lung retention) align with reference guidelines such as ICRP 38.
c. To estimate an ingestion ALI (Annual Limit on Intake) as well as inhalation ALI and DAC (Derived Air Concentration) for 40K, we would need to compare the calculated committed effective doses from parts a and b with the published metabolic data. ALI and DAC values can be found in publications or databases such as the International Atomic Energy Agency's "Handbook of Parameter Values for the Prediction of Radionuclide Transfer in Terrestrial and Freshwater Environments."
By comparing the calculated committed effective doses to the published values, we can estimate the ingestion ALI and inhalation ALI and DAC for 40K.
Remember to refer to authoritative sources such as ICRP reports and other relevant publications to obtain accurate and up-to-date data for dose coefficients and parameters.