uses and risks of radiation Flashcards
1
Q
gamma sources
A
medical tracers
2
Q
how do medical tracers work?
A
- radioactive isotopes are injected/swallowed and their progress around the body is followed using an external detector
- a computer converts the reading into a display, showing where the strongest reading is coming from
3
Q
iodine-123
A
- absorbed by the thyroid gland
- gives out radiation
- can be detected to indicate whether the thyroid gland is taking in iodine, as it should
4
Q
why are gamma emitters used in medical tracing?
A
- so radiation passes out of the body without causing too much ionisation
- short half-life so radioactivity quickly disappears
5
Q
radiotherapy
A
- gamma rays directed carefully at the right dosage to kill cancer cells
- some damage done to normal cells which makes patient feel ill
- beta emitters also used as radiation emitting implants
6
Q
when does tissue damage occur?
A
when radiation enters living cells and ionises atoms with them
7
Q
what can happen with too low doses?
A
- cause minor damage without killing cells
- give rise to mutant cells
- divide uncontrollably
- this is cancer
8
Q
what can happen with too high doses?
A
- kill cells completely
- cause radiation sickness if a lot of cells get blasted at once
9
Q
perceived risk
A
how risky a person thinks something is
10
Q
benefits of tracers that outweigh negatives
A
- used to diagnose life threatening conditions
- risk of cancer from one tracer very small
11
Q
benefits of radiotherapy that outweighs negatives
A
- can get rid of cancer entirely
- however prolonged exposure poses future risks and cause side effects
