background radiation

• Background radiation


  Radiation that is present all around us all the time
• Main sources of natural background radiation

  • Radioactive rock (e.g. granite)
  • Cosmic rays from space
• Main sources of man-made background radiation

  • Fallout from nuclear weapons testing
  • Nuclear accidents (e.g. Fukushima)
• Nuclear testing has been mainly phased out, but the radioactive isotopes still remain in the environment
• The Fukushima nuclear accident in 2011 released huge amounts of radioactive isotopes into the environment, and it will take decades to clean up
• Location and occupation


  Can affect your exposure to background radiation
• People living in regions with large amounts of granite, such as Cornwall or northern Scotland, experience greater levels of background radiation
• Cabin crew and airline pilots may be exposed to higher levels of cosmic radiation
• Dose of radiation


  Measured in sieverts or millisieverts (1 millisievert = 1/1000 sievert)