Hazards and use of radioactive emissions and background

• Give 4 sources of background radiation

  1. Rocks
  2. cosmic rays from space
  3. nuclear weapon testing
  4. nuclear accidents
• How should back ground radiation be dealt with in calculations

  The background count should be subtracted from any readings before calculations are attempted
• What’s the unit used to measure radiation dosage

  Sieverts (Sv)
• How many millisieverts equal 1 sievert

  1000 millisieverts = 1 sievert
• Why might the radiation dosage that different people experience differ

  • Some occupations involve working with radiation
  • background radiation differs with location due to things such as the locality of nuclear power stations or radiation related testings
• What factor determines how dangerous a particular radioactive isotope

  The half life of the isotope
• Why are isotopes with long half life’s particularly harmful

  • They remain radioactive for much longer periods of time
  • they must be stored in specific ways to avoid humans and the environment from being exposed to radiation for too long
• Star two uses of nuclear radiation in the field of medicine

  1. Examining of internal organs
  2. controlling and destroying unwanted tissue
• How is radiation used in sterilisation

  Gamma emitters are used to kill bacteria / parasites on equipment
• Explain the process of radio therapy

  • Gamma emitters direct gamma rays at the cancerous cells
  • the cancerous cells absorb the radiation and are killed
• How are medical tracers chosen

  They should have a short half life and decay into a stable isotope which can be excreted

  they should only release gamma radiation since it’s weakly ionising and can easily pass through body tissue without damaging it