| A | B |
|---|
| A radionuclide having a decay constant of 5E-02 per day has a biological removal constant of 5E-02 per day for a particular organ of reference | 6.93 days |
| In the shilding of gamma rays, the dose bildup factor accounts primarily for: | the dose contribution due to Compton scattered photons |
| ICRP stands for | Internatinal Commission on Radiological Programs |
| Acute radiation exposures are those | involving relatively large doses in a relatively short time. |
| A worker is exposed to an I-131 concentration of 3.6E-7 uCi/cc for 45 minutes. The DAC for I-131 is 2E-8 uCi/cc. Assuming that no respiratory equipment was used, how many DAC-hours of I-131 did the worker receive? | 14 DAC hours. |
| Which of the following is a symptom of the hemopoietic syndrome? | Depression of the immune system due to loss of white blood cells |
| Which of the following items is not requlated by the Nuclear Regulatory Commission under the Atomic Energy Act of 1954? | Natural uranium and thorium. |
| The dose buildup factor at a particular point outside the shield of a monoenergetic point gamma source is 1.5. The percentage of the dose contributed by secondary or scattered photons is: | 50% |
| An individual breathes a concentration of 2.0E-7 microcuries per milliliter of Cesium-137 for two and one-half hours. If the DAC for Cesium-137 is 6.0E-8 microcuries per milliliter, his approximate effective dose will be: | 21 millirem |
| A sample counted for 10 minutes resulted in 1000 counts. The background count was 250 counts over a 10 minute period. Assuming negligible radioactive decay of the sample during counting, the net count rate in counts per minute and the standard deviation are approximately: | 75 +/- 10 |
| Explain the mechanisms of direct and indirect action. | Direct action is when radiation (typically heavy particles) interact directly with the DNA, causing damage. Indirect action is where the radiation interacts with water in the body. THis causes ionizations, which result in free radicals. These free radicals then go on to damage DNA. Since many of these compounds are relatively stable, they can go on to damage areas outside of the irradiation portion of the body. |
| Define ALARA and explain what is means in the context of radiation protection | ALARA is As Low As Resonably Achievable. THis means protecting individuals from as much radiation as realisticaly possible. It is impossible to protect an individual from all radiation, especially becuase you recive a dose from the sun just being outdoors. Instead you try and limit radiation dose to a small enough ammount as as not to dramatically increase health risks. |
| What are the three routes of entry considered in internal radiaiton protection? | Ingestion Inhilation Absorption |
| Explain the difference between stochastic and non-stochastic effects, and give an example of each. | Stochastic effects are when an increase in dose increases the probability of a certain effect, where non-stochastic effects are where increase in dose increases the severity of a certain effect. An example of a stochastic effect is cancer. An example of a non-stochastic effect is hair loss or radiation burns. |
| A radionuclide having a decay constant of 5E-02 per day has a biological removal constant of 5E-02 per day for a particular organ of reference. The effective half-life is | 6.93 days |
| In the shilding of gamma rays, the dose bulding factor accounts primarily for: | the dose contribution due to Compton scattered photons. |
| ICRP stands for | International Commission on Radiological Protection |
| Acute radiation exposures are those | involving relatively large doses in a relatively short time. |
| A worker is exposed to an I-131 concentration of 3.6E-7 uCi/cc for 45 minutes. The DAC for I-131 is 2E-8 uCi/cc. Assuming that no respiratory equipment was used, how many DAC-hours of I-131 did the worker receive? | 14 DAC hours |
| Which of the following is a symptom of the hemopoietic syndrome? | Reddening of the skin |
| Which of the following items is not regulated by the Nuclear Regulatory Commission under the Atomic Energy Act of 1954? | Medical X-ray machines |
| The dose buildup factor at a particular point outside fothe sheild of a monoenergetic point gamma source is 1.5. The percentage of the dose contributed by secondary or scattered photons is | 33% |
| An individual breathes a concentration of 2.0E-7 microcuries per milliliter of Cesium-137 for two and one-half hours. If the DAC for Cesium-137 is 6.0E-8 microcuries per milliliter, his approximate effective dose will be: | 21 millirem. |
| A sample counted for 10 minutes resulted in 1000 counts. The background count was 250 counts over a 10 minute period. Assuming negligible radioactive decay of the sample during counting, the net count rate in counts per minute and the standard deviation are approximately: | 75 +/- 3.5 |
| Explain the mechanisms of direct and indirect action | In direct action, radiation damage sthe cell by depositing energy of damaged area (breakdown cells, DNA damage) In in-direct aciton, the radiation does damage by depositing energy else where, and the products cause damage. Often done by the radiation creating ions/free radicals where chemically react with biological materials and do damage. |
| Define ALARA and explain what it means in the context of radiation protection. | As Low As Reasonably Achievable This means radiation levels should be controlled as much as possible. We know that it is impossible/impractical to try to store all radiation, so whatever is practical should be done. Just becasue something is below the limit doesn't mean its ok |
| What are the three routes of entry considered in internal radiation protection? | Absorption, ingestion and inhalation |
| Explain the differnece between stochastic and non-stochastic effects, and give an example of each | Stochastic effects have to do with probability. Any amount of radiation could theordically cause these effects and chance increases with does they are also long term effects (cancer) -Non stochastic are usually short term effects which occur at given levels of radiation. Sometimes these have a threshold (radiation burn, sun burn, hair loss) |
