Concept explainers
(a)
The dose to the thyroid due to an acute exposure of
(a)
Answer to Problem 11.9P
Explanation of Solution
Given:
Mass of thyroid is
Formula used:
The initial dose rate is
Where,
Calculation:
According to Appendix C average person breaths 20 L per min. So, the light activity is:
The below table is drawn referring ICRP 2:
|
| |||||
|
|
|
|
|
| |
Thyroid |
|
|
|
|
|
|
Body |
|
|
|
|
|
|
The dose is calculated as:
The initial dose rate for is
For
So, dose to the thyroid is:
Conclusion:
The dose to the thyroid due to an acute exposure of
(b)
The dose to the thyroid due to an acute exposure of
(b)
Answer to Problem 11.9P
Explanation of Solution
Given:
Mass of thyroid is
Formula used:
The initial dose rate is,
Where,
Calculation:
The initial dose rate is,
For
So, dose to the thyroid is:
Conclusion:
The dose to the thyroid due to an acute exposure of
(c)
The total body dose due to the protein bound iodine.
(c)
Answer to Problem 11.9P
Explanation of Solution
Given:
Mass of body is
Formula used:
The initial dose rate is,
Where,
Calculation:
The dose is calculated as:
The initial dose rate for is
For
So, dose to the thyroid is:
Conclusion:
The total body dose due to the protein bound iodine is
(d)
The effective dose for body from each isotope.
(d)
Answer to Problem 11.9P
Explanation of Solution
Given:
Mass of body is
Formula used:
The initial dose rate is,
Where,
Calculation:
The dose is calculated as:
The initial dose rate for is,
For
So, dose to the thyroid is:
Conclusion:
The effective dose for body from each isotope is
Want to see more full solutions like this?
- Estimate the exposure rate 2 m from 4 Ci sources of 57Co,22Na,65Zn?Exposure Rate constant for 57Co=0.9 (R.cm2) / (hr.mCi)Exposure Rate constant for 22Na =12 (R.cm2) / (hr.mCi)Exposure Rate constant for 65Zn =2.7 (R.cm2) / (hr.mCi)arrow_forwardIf a patient receives a dose with an activity of 37.5 mCi of technetium-99m for cardiac imaging, how much radioactivity will be left in the patient’s body 72 hours after injection?arrow_forwardA particular radioactive source produces 100 mrad of 2-MeV gamma rays per hour at a distance of 1.0 m. (a) How long could a person stand at this distance before accumulating an intolerable dose of 1 rem? (b) Assuming the gamma radiation is emitted uniformly in all directions, at what distance would a person receive a dose of 10 mrad/h from this source?arrow_forward
- given 4hrs of 80dBA exposure ,2hrs of90 dBA exposure and 2hrs of 85 dBA exposure,what is the % dose? is this person overexposed to noisearrow_forwardA particular radioactive source produces 100. mrad of 2- MeV gamma rays per hour at a distance of 1.0 m. (a) How long could a person stand at this distance before accumulating an intolerable dose of 1.0 rem? (b) Assuming the gamma radiation is emitted uniformly in all directions, at what distance would a person receive a dose of 10. mrad/h from this source?arrow_forwardSuppose one load irradiation plant uses a 137Cs source while another uses an equal activity of 60Co. Assuming equal fractions of the (rays from the sources are absorbed, why is more time needed to get the same dose using me 137Cs source?arrow_forward
- The radionuclide 32P (T1/2 = 14.28 d) is often used as a tracer to follow the course of biochemical reactions involving phosphorus. (a) If the counting rate in a particular experimental setup is initially 3050 counts/s, how much time will the rate take to fall to 170 counts/s? (b) A solution containing 32P is fed to the root system of an experimental tomato plant, and the 32P activity in a leaf is measured 3.48 days later. By what factor must this reading be multiplied to correct for the decay that has occurred since the experiment began?arrow_forwardHow many Gy of exposure is needed to give a canceroustumor a dose of 40 Sv if it is exposed to α activity?arrow_forwardif a normal dose CT scan delivers 700 mrem of radiation, how many CT scans would a patient have to have to feel mild radiation sickness (50 rem)?arrow_forward
- The (effective) dose to a patient can be measured in milli-Serverts (mSv) or expressed as the time taken to receive the equivalent dose from background radiation. A certain radiograph gives a 1.232 mSv dose which is equivalent to a background radiation dose of 32 weeks.a)How many days in 32 weeks? Give your answer as a whole number. b)Using the information for the radiograph in this question, calculate the UK daily background dose (in mSv/day). Give your answer to 5 decimal places and use it to this accuracy, if needed in subsequent calculations. c)Another radiograph has a 0.0054 mSv dose. Work out the equivalent background dose (in days) for this radiograph. Give your answer to 2 decimal places and use it to this accuracy in any subsequent calculations. d)How many hours is the number of days in part c) equivalent to? Give your answer to 2 decimal places.arrow_forwardWhat is the half-life, t½, (in hr) when the concentration was 100 mg/L?arrow_forwardWhat is the dose in mSv for 1.5 mGy of α exposure?arrow_forward
- College PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax College