Uses and Risk - Radiation

Question 1

what happens when radiation enters living cells

Answer 1

• ionise atoms + molecules within them –> tissue damage

Question 2

what effects do lower doses have

Answer 2

• minor damage without killing cells
• can give rise to mutant cells which divide uncontrollably = cancer

Question 3

what effects do higher doses have

Answer 3

• kill cells completely causing radiation sickness (vomiting, tiredness, hair loss), if a lot of cells killed at one

Question 4

what are the 2 main uses of radiation in medicine

Answer 4

• medical tracers
• radiotherapy

Question 5

what radiation source is normally used in medical traacers

Answer 5

gamma

Question 6

explain how medical tracers work

Answer 6

• radioactive isotopes injected or swallowed
• medical tracers trace the substance through the body using a external detector
• computer converts reading to display where strongest reding is coming from

Question 7

example for where medical tracers can be used on in the body

Answer 7

• use of iodine-123, which is absorbed by the thyroid gland
• gives out radiation which can be **detected* to show whether thyroid gland is taking in iodine as it should

Question 8

what type of radioactive isotope is normally taken within the body and why

Answer 8

Gamma- so radiation passes out of the body without causing much ionisation
- should have a short half-life so radioactivity inside the patient quickly disappears

Question 9

describe how radiotherapy kills cancer

Answer 9

• Gamma beams directed carefully and at the right dosage to kill cancer cells without damaging normal cells
• Radiation-emitting implants can also be put next to or inside tumour

Question 10

what is the downside to radioactivity

Answer 10

• fair bit of damage to healthy cells –> can make patient feel ill

Question 11

why do people still use radioactive material if there are risks

Answer 11

benefits outweigh risks (esp. for cancer)