Background Radiation and Contamination

Question 1

What is meant by background radiation? Give two sources of it.

Answer 1

Background radiation is the low-level radiation that’s around us all the time. Sources include e.g. air, rocks, cosmic rays, fallout from nuclear explosions, nuclear waste

Question 2

True or false? An object irradiated with alpha, beta or gamma radiation will become radioactive.

Answer 2

False

An irradiated object is exposed to nuclear radiation, but doesn’t become radioactive

Question 3

Describe how ionising radiation can damage the body.

Answer 3

E.g. radiation can cause damage to cells which can give rise to mutant cells that divide uncontrollably, causing cancer. Radiation can also kill cells, which causes radiation sickness. This leads to vomiting, tiredness and hair loss

Question 4

What is the difference between irradiation and contamination?

Answer 4

Irradiation is exposure to radiation, whereas contamination is unwanted radioactive atoms getting onto an object

Question 5

Give one example of a way to reduce the risks of irradiation to medical staff. How can their exposure to radiation be monitored?

Answer 5

e.g. standing behind barriers, leaving the room, using remote-controlled arms. Exposure can be monitored by wearing photographic film badges

Question 6

Explain why it is usually more dangerous to be contaminated by alpha radiation from the same source.

Answer 6

Alpha particles are strongly ionising. If the inside of the body becomes contaminated with an alpha source, the alpha particles can do a lot of damage in a localised area. An irradiating alpha source won’t be as dangerous, as the alpha particles will mostly be absorbed by the air before reaching the body/ can’t penetrate the skin