Dangers of radiation Flashcards
What does ionising radiation do to atoms?
it knocks electrons out of atoms, turning them into ions
ionisation and cellular mutation
ions are formed by radiation, and are very reactive and can cause mutations to the DNA in cells, leading to cancer
- energy transferred by ionising radiation removes electrons from atoms to form ions
- ions are reactive and cause mutations to the DNA in cells
- damaged DNA can lead to cancer
ionising radiation can also cause damage to cell tissue in the form of radiation burns
when its energy is high enough it can also kill cells
precautions and safety (3)
limiting the time of exposure - keep the time that a person is in contact with ionising radiation as low as possible
wearing protective clothing - wearing a lead apron will absorb much of the ionising radiation
increasing the distance from the person to the radioactive source - the further a person is from the ionising radiation, the less damage it will do
half-life of a source and danger
the greater the half-life of a source is, the longer it will remain dangerous
precautions that can be taken to monitor/minimise exposure (specific) (2)
wearing a film badge
holding a radioactive source away from a person using tongs, and not pointing it at people
Describe two precautions taken by dentists and dental nurses to reduce their exposure to ionising radiation while taking an X-ray. [2]
1) they go out of the room in which the X-ray is taking place
2) they keep the X-ray pulse as short as possible (this also minimises the patient’s exposure)
State two ways in which ionising radiation can be dangerous to humans [2]
can cause cells to become ionised, which leads to chemical reaction taking place in cells
causing them to die or mutate, which can lead to cancer
Explain why ionising radiation is more dangerous than non-ionising radiation [3]
ionising radiation knocks electrons from shells, making them more reactive and allowing change to DNA to occur, whereas non ionising radiation cannot do this as there is not enough energy to knock electrons from cells
Film badges have been superseded in some places by the use of semiconductor devices that measure levels of ionising radiation. Suggest why these devices are preferred to film badges. [3]
measure radiation using a semiconductor crystal as opposed to film (cheaper?), record specific exposure, do not need to be developed so can provide information immediately, are more reliable/less likely to give faulty results
