Exam 5 Flashcards
Radiation-induced cataracts in humans follow a ______ dose–response relationship.
- threshold, linear
- threshold, nonlinear
- nonthreshold, linear
- nonthreshold, nonlinear
threshold, nonlinear
Which of the following late effects caused by exposure to ionizing radiation is considered to be most important?
- None; all are considered to be of equal importance.
- Cataract formation
- Cancer
- Embryologic or birth defects
Cancer
In which of the following human populations is the risk of causing radiation-induced cancer not directly measurable?
- All patients in diagnostic radiology subjected to a radiation dose below 0.1 Sv
- Chernobyl radiation accident victims living in contaminated villages
- Atomic bomb survivors
1 only
Existing data on radiation-induced genetic effects in humans
- Prove conclusively that radiation causes major genetic effects.
- Prove conclusively that radiation causes only minor genetic effects.
- Prove conclusively that radiation does not cause genetic effects.
- Are both contradictory and inconclusive.
Are both contradictory and inconclusive.
When a prediction is made that the number of excess cancers rises as the natural incidence of cancer increases with advancing age in the population, the risk is considered to be
- quadratic.
- relative.
- absolute.
- excess.
relative.
What do agents such as specific chemicals, viruses, and ionizing radiation have in common?
- They always cause spontaneous abortions during the first trimester of pregnancy.
- They can increase the frequency of mutations in only those members of the population who are already genetically impaired.
- They are all mutagens that may increase the frequency of mutations.
- Nothing
They are all mutagens that may increase the frequency of mutations.
Which of the following are sources of low-level radiation exposure?
- X-rays and radioactive materials used for diagnostic purposes.
- Employment-related exposure in medicine and industry.
- Natural background radiation.
1, 2, and 3
After the Chernobyl disaster in 1986, an attempt was made to prevent thyroid cancer in Poland and some other countries, resulting from the accidental overdose of iodine-131. _______________ was administered to children as a substitute to block the gland’s uptake of iodine-131.
- Ibuprofen
- Potassium iodide
- Sodium bicarbonate
- Potassium bromide
Potassium iodide
The term linear non-threshold relationship implies that the biologic response to ionizing radiation is
- inversely proportional to the dose all the way down to levels approaching zero.
- inversely proportional to the square of the dose all the way down to levels approaching zero.
- directly proportional to the square of the dose all the way down to levels approaching zero.
- directly proportional to the dose all the way down to levels approaching zero.
directly proportional to the dose all the way down to levels approaching zero.
Genetic mutations at the molecular level are called
- molecular mutations.
- chromosome mutations.
- molecular mutations.
- point mutations.
point mutations.
Which of the following terms involves a random effect of ionizing radiation?
- Early tissue reactions
- Change in white blood cell count
- Stochastic event
- Reddening of the skin
Stochastic event
Which of the following agencies was previously known as the Atomic Energy Commission?
- NRC
- NCRP
- FDA
- ICRP
NRC
Determine the cumulative effective dose (CumEfD) limit to the whole body of an occupationally exposed person who is 46 years old.
- 46 mSv
- 4.6 mSv
- 4600 mSv
- 460 mSv
460 mSv
The main function of the Nuclear Regulatory Commission (NRC) is to
- inspect imaging facilities.
- oversee the nuclear energy industry.
- regulate imaging facilities
2 only
The effective dose (EfD) limiting system supersedes
- the Consumer-Patient Radiation Health and Safety Act of 1981.
- all Occupational Safety and Health Administration (OSHA) regulations.
- the maximum permissible dose (MPD) system.
- all Nuclear Regulatory Commission (NRC) regulations.
the maximum permissible dose (MPD) system.
