|| RTSM Table Of Contents ||

RADIATION SAFETY TRAINING MANUAL

CHAPTER 12
SELF-ASSESSMENT QUIZ & ANSWERS

QUIZ

CHAPTER 1: PROPERTIES OF IONIZING RADIATION

1. What thickness of lead is required to give complete absorption of gamma-rays?

2. When comparing Beta-emitters, the average path length in air is proportional to what property of the Beta-particle?

3. Why is it better to use plastic, rather than lead, to shield energetic beta-emitters such as ³²P?

4. What is the difference between the shielding required for positrons and for negatively charged beta-particles of the same energy?

5. The path length of a beta-particle in water is about what fraction of its path length in air?

6. The path length of a beta-particle in water is about what fraction of its path length in lead?

7. You purchased a radionuclide with a 14 day half-life. Eight weeks later, how much is left?

8. Both gamma-rays and x-rays are electromagnetic radiation. How do they differ?

9. If the intensity of gamma-radiation at 1 cm is 1 mR/hr, what is it at 10 cm?

10. The half-value layer of lead for ¹²⁵I is .02 mm. What fraction of the gamma-rays gets through 0.04 mm?

11. What is the value of the curie expressed in Becquerels?

CHAPTER 2: UNITS FOR MEASURING IONIZING RADIATION

1. What are the three energy units used to measure the interaction of ionizing radiation with matter?

2. For beta, gamma and x-rays how are these three units related?

3. The total damage caused by radioactive material is dependent on:

a. the number of disintegrations per second

b. the energy of the decay particle

c. the nature of the decay particle

d. all of the above.

4. Match the following terms:

CHAPTER 3: MAXIMUM PERMISSIBLE EXPOSURES

1. The State of California's limit for whole body radiation exposure is 5000 mrem/yr for people over 18. What is the UCSF alert level?

2. Do we know that exposure to the maximum amounts approved by the State will cause cancer, or is this an extrapolation from high doses?

3. What is the philosophy of UCSF on radiation exposure reduction?

4. How does the background radiation in San Francisco compare with the State guideline for maximum radiation exposure per year?

5. If a researcher receives a dose of 10 rem/yr to the skin in one calendar year, has he/she exceeded the maximum permitted dose?

6. Does the State allow radiation users and non-users to be exposed to the same radiation levels?

7. How much radiation can a fetus maximally be exposed to during gestation?

8. Have the dangers due to low levels of exposure to ionizing radiation been scientifically proven?

9. If you are pregnant and you have received 0.5 rem of exposure in the first three months of pregnancy, what should you do?

10. As supervisor of female workers considering pregnancy and who use ionizing radiation, your responsibilities are:

a. none, the responsibilities are the woman's

b. to encourage her to read this Training Manual

c. to insist that she know of and be familiar with the contents of the Supplemental Guide on Prenatal Radiation Exposure available from EH&S.

CHAPTER 4: BIOLOGICAL EFFECTS OF RADIATION

1.Give an example of (a) a prompt and (b) a delayed somatic effect due to high levels of radiation.

2. Are genetic delayed effects of ionizing radiation less or more severe than the cancer producing effects?

3. Which types of tissue are more sensitive to radiation?

CHAPTER 5: Safety Hazards Associated with Commonly Used Radionuclides

1. The annual limit of ingestion of radionuclides gives the maximum amount that can be inadvertently ingested or inhaled yet remain below the guidelines. For ¹²⁵I it is:

a. 1 mCi

b. 10 uCi

c. 0.1 uCi

2. What depth through the skin do ³H, ¹⁴C and ³²P penetrate?

3. 1 uCi of ¹⁴C on 1 cm of skin delivers approximately how much radiation to basal cells of the skin:

a. none

b. about 3 mrads/hr

c. about 3 rads/hr?

4. Will external ³²P sources do much radiation damage to internal organs?

5. The commonly used radionuclide ¹²⁵I has a Gamma Factor of 0.7 roentgens/hr/mCi. How many roentgens/hr are generated by 1 mCi at 1 cm? At 10 cm from the source?

6. Why is the eye the major organ at risk when working with an external source of ³²P?

7. What level of radiation does UCSF allow at 30 cm from a stored gamma-emitter?

CHAPTER 6: PRACTICAL STEPS TO RADIATION SAFETY

1. Why should one practice a procedure first with non-radioactive material?

2. What are tongs used for in a well-equipped radiation safety laboratory?

3. If it takes 0.1 mm of lead to reduce ¹²⁵I generated gamma-rays by one-tenth, how much is needed to reduce it by one-thousandth?

4. Why are the regulations so insistent on the absence of food and drink from areas where radionuclides are used or stored?

5. When a potentially volatile radionuclide such as ¹²⁵I is used, where must experiments be performed?

6. What four precautions are essential for every manipulation involving radionuclides?

7. If you have been working with ³H, how is contamination assayed?

8. What should be done about radioactive signs on cartons used for shipping before disposal?

9. Before storing a radioactive sample or leaving a radioactive waste container on your bench, it should be marked with radioactive tape specifying what?

10. What thickness of lucite effectively screens ³²P:

a. none

b. 1 mm

c. 1 cm

11. Why should deliveries of radionuclides be opened wearing disposable gloves?

12. What bookkeeping is required when a new batch of radionuclides arrives?

13. Why should one wear two pairs of gloves during iodinations and change them every 10 minutes?

14. Why should ¹²⁵I and ¹³¹I wastes be wrapped before disposal?

15. When is mouth pipetting allowed?

16. Can you lend 5 mCi of Na¹²⁵I to a laboratory until their license gets approved?

17. Can you lend 5 mCi of Na¹²⁵I to another laboratory that has run out and needs it?

18. You may store food in a refrigerator containing radionuclides if the food is kept in a sealed container. True or False?

19. You must use a specialized container for the disposal of used hypodermic syringes prior to placing them in the dry radioactive waste box. True or False?

20. Your G-M counter registers 150 mR/hr. How long can you work in the area and remain under the campus' monthly limit?

21. You must monitor your laboratory by wipe method:

a. monthly or weekly as specified by the activity used in the lab

b. only when EH&S detects contamination

c. from time to time

d. twice per year

e. after each experiment in which a volatile iodide is used

CHAPTER 7: Measurements of Radiation Exposure

1. Your film badge records

a. ³²P and ¹⁴C

b. ³H and ⁶⁰Co

c. ³²P and ¹²⁵I

d. ³⁵S and ¹⁴C

e. ³H and ¹²⁵I

2. You are required to wear your ring badge when working with 1 mCi of ³²P. True or False?

3. Finger rings should be worn when working with which radionuclides?

4. A thyroid scan must be performed if more than what quantity of volatile ¹²⁵I is used routinely per month?

5. What is the equivalent amount for ¹³¹I?

6. If you work with more than 100 mCi of a ³H-nucleotide precursor, what are you required to do?

7. Does a Geiger-Mueller counter measure mRoentgens directly?

8. If, while monitoring your laboratory, you detect some small amount of contamination, you must:

a. disregard the contamination

b. clean it up if it is over 2 x background cpm

c. call Radiation Safety and report the findings

d. send Radiation Safety a "Report of Laboratory Contamination" form

CHAPTER 8: RECORD KEEPING

1.How often are you required to monitor your laboratory?

a. each day

b. each week

c. each month

d. each year

e. as specific by the activity amount being used, weekly if > or = 100 uCi, monthly if < 100 uCi.

2. Why are you required to keep a map of your laboratory?

a. to know where to find radionuclides

b. to keep a record of where you have monitored for contamination

c. to help you if lost

d. all of the above

CHAPTER 9: RADIOACTIVE WASTE DISPOSAL

1. What is the limit for "de minimus" liquid scintillation vials?

2. How is radioactive waste segregated:

a. by category (e.g. dry, biological)

b. by half-life

c. by disposal cost

d. (a) & (b)

3. What do you do with radioactive scintillation vials?

a. separate them into those with ³H and ¹⁴C

b. make sure levels of radioactivity are below 0.5 mCi/ml

c. mark them "counting vials"

d. keep them in storage flats, if possible

e. all of the above

4. Dry waste containers must have what three items of information in addition to the radiation symbol?

a. chemical form

b. name of Principal Investigator

c. radionuclides and amount

d. date

e. recharge account number

5. When disposing of an outer shipping box that a vendor has used to send you radionuclides, you:

a. must use the radioactive trash box in your laboratory and crush the shipping container to save space.

b. may throw it in the normal trash.

c. may leave it in the hall with a note saying "trash", for custodial personnel to remove.

d. monitor to verify it is not contaminated, remove or deface all labels then throw in normal trash.

e. must bring it down to the loading docks, separate from your regular waste, on the assigned day for pickups.

6.You accidentally spill some radionuclide on yourself and it contaminates your skin. You must:

a. call Radiation Safety

b. go to the Student Health center

c. wash the skin in cold water with hand soap

d. first (c) then (a)

7. Aqueous liquid radioactive waste must:

a. contain no organic compounds

b. be stored in capped plastic jars

c. be segregated by half-life category

d. all of the above

8. Contaminated animal carcasses must be:

a. packaged in red bags

b. taken to the designated freezer

c. segregated by half-life category

d. all of the above

9. Sharps and blades used in animal surgery must be:

a. packaged with animal carcasses

b. packaged with dry waste

c. packaged in sharps container

CHAPTER 10: EMERGENCY PROCEDURES

1. What should be done first if there is a major accident involving radioactivity?

2. What is the best method of skin decontamination?

3. What if the skin is broken?

SELF-ASSESSMENT QUIZ ANSWERS

CHAPTER 1: PROPERTIES OF IONIZING RADIATION

1. Statistically speaking there is no such thickness.

2. E_mean

3. To minimize Bremsstrahlung production.

4. Positrons produce x-rays by annihilation.

5. About 1/1000

6. About 1/10,000

7. 1/16

8. Their origin; x-rays come from electron shells; gamma-rays from the nucleus.

9. 1/100

10. One-quarter

11. 3.7x10¹⁰ Becquerels

CHAPTER 2: UNITS FOR MEASURING IONIZING RADIATION

1. Roentgens, rems, rads

2. Nominally the same

3. (d)

4.:

(d) Roentgen a) Unit of radioactivity

(c) Rem b) Amount of radioactivity/gram

(a) Curie c) Unit of radiation dose

(b) Specific activity d) Unit of radiation exposure

(e) Film badge e) A device which measures cumulative radiation dose

CHAPTER 3: MAXIMUM PERMISSIBLE EXPOSURES

1. 100 mrem/month

2. The latter

3. The philosophy of ALARA, As Low As is Reasonably Achievable.

4. One fiftieth

5. No. The maximum permissible dose to the hands is 50 rem/year as opposed to 5 rem for the whole body.

6. No, those who are certified as trained in the use of ionizing radiation can receive up to 10 times more.

7. 0.5 rems/gestation period (500 mrem/gestation period)

8. No, they are extrapolations from high levels of radiation. They could be low estimates or high.

9. Stop working with ionizing radiation immediately, until a fetal dose evaluation is performed.

10. (c)

CHAPTER 4: BIOLOGICAL EFFECTS OF RADIATION

1. (a) Radiation burns, sterility, etc., (b) Cancer

2. Less

3. Those which are rapidly dividing.

CHAPTER 5: SAFETY HAZARDS ASSOCIATED WITH COMMONLY USED RADIONUCLIDES

1. (b)

2. 0, 0.3 mm and 1 cm

3. (c)

4. No, their beta-particles only penetrate 1 cm in tissue

5. 0.7, 0.007

6. Since ³²P only penetrates 1 cm into tissue, the eye is the major radiation sensitive organ exposed.

7. 2 mR/hr

CHAPTER 6: PRACTICAL STEPS TO RADIATION SAFETY

1. To reduce time of exposure by practice.

2. To enhance distance between the user and the source.

3. 0.3 mm

4. Because the major danger, especially for low energy beta-emitters, is from ingestion.

5. In an approved fume hood.

6.:

a. Use of protective clothing, gloves and lab coats.

b. Anticipation of accidental spills by using absorbent paper, trays, etc.

c. Disposing of waste appropriately afterwards.

d. Monitoring the work area for contamination.

7. By wipe and liquid scintillation counting.

8. Defaced or removed.

9. The date, the radionuclide, the amount and the user.

10. (c)

11. Shipments are often contaminated due to leakage during transport.

12. The date, amount and chemical form must be logged into the laboratory usage records.

13. Iodide vapor penetrates through the material.

14. To reduce leaks due to volatilization.

15. NEVER

16. No

17. If they have authorization to receive 5 mCi of Na¹²⁵I, and after completion of the proper "Transfer Form".

18. False

19. True

20. Forty minutes

21. (a)

CHAPTER 7: MEASUREMENTS OF RADIATION EXPOSURE

1. (c)

2. True

3. High energy beta and gamma-emitters.

4. 15 mCi

5. 1 mCi

6. Tritium urinalysis after each use.

7. No. It measures events, that is, counts per minute independent of energy. Conversion of cpm to mR/hr depends on the calibration of the system to a specific energy.

8. (b)

CHAPTER 8: RECORD KEEPING

1. (e)

2. (b)

CHAPTER 9: RADIOACTIVE WASTE DISPOSAL

1. 0.05 uCi/ml

2. (d)

3. (e)

4. (a, c, d)

5. (d)

6. (d)

7. (d)

8. (d)

9. (c)

CHAPTER 10: Emergency procedures

1.:

a. Attend to injured

b. Wash contaminated skin

c. Call your DSA

d. Call the Radiation Safety Office immediately

2. Thorough washing with soap and water.

3. Wash with a strong stream of water and seek medical help.

.|| Top Of Page || Glossary || Table Of Contents ||