Radioactive Emissions & Background Radiation

• What is one source of background radiation?

  Rocks
• Name a source of background radiation from space.

  Cosmic rays from space
• What is a source of background radiation related to military activities?

  Nuclear weapon testing
• What is a source of background radiation from industrial incidents?

  Nuclear accidents
• How should background radiation be treated in calculations?

  It should be subtracted from readings
• What unit is used to measure radiation dosage?

  Sieverts (Sv)
• How many millisieverts are in one sievert?

  1000 millisieverts = 1 sievert
• Why might radiation dosage vary among individuals?

  • Some occupations involve radiation exposure
  • Background radiation varies by location
  • Locality of nuclear power stations affects dosage
• What factor determines the danger level of a radioactive isotope?

  The half-life of the isotope
• Why are isotopes with long half-lives particularly harmful?

  • Remain radioactive for longer periods
  • Require specific storage to avoid exposure
• What are two uses of nuclear radiation in medicine?

  1. Examining internal organs
  2. Controlling and destroying unwanted tissue
• How is radiation used in sterilization?

  Gamma emitters kill bacteria on equipment
• Explain the process of radiotherapy.

  • Gamma emitters direct gamma rays at cancer cells
  • Cancer cells absorb radiation and are killed
• How are medical tracers selected for use?

  They should have a short half-life
• What type of radiation should medical tracers release?

  Only gamma radiation
• Why is gamma radiation preferred for medical tracers?

  It is weakly ionising and penetrates tissue