4.3: hazards and uses of radioactive emissions and background radiation

some sources of background radiation are

rocks, cosmic rays from space, nuclear weapon testing, nuclear accident

in calculations, how should background radiation be dealt with

should be subtracted from any readings before calculations are attempted

how is radiation dosage measured

sieverts (Sv)

why might the radiation dosage people experience differ

some occupations involve working with radiation, background radiation differs with location

what determines how dangerous a radioactive isotope is

the half-life of the isotope

isotopes with …………. are more harmful

longer half-lifes

why are isotopes with long half-lives more harmful

they remain radioactive for longer so must be stored in specific ways to avoid humans and the environment being exposed to radiation for too long

how is nuclear radiation used in the field of medicine

examining of internal organs, controlling and destroying unwanted tissue

how is radiation used in sterilisation

gamma emitters are used to kill bacteria/parasites on equipment

the process of radiotherapy is

gamma emitters direct gamma rays at cancerous cells which absorb the radiation and are killed

medical tracers are chosen by

them having a short half-life and decay into stable atoms which can be excreted, they should only release gamma radiation as its the least ionising and can pass through body tissue without damaging it