Background Radiation

• What is meant by background radiation?

  Radiation present in the environment all the time
• What are the main sources of background radiation?

  Natural and man-made sources
• What is the first natural source of background radiation?

  Radioactive rock in the ground
• Which type of rock is a major source of background radiation in the UK?

  Granite
• What are cosmic rays?

  High energy particles from space
• What is one source of cosmic rays?

  Supernovae, which are exploding stars
• What is the first man-made source of background radiation?

  Fallout from nuclear weapons testing
• Why do radioactive isotopes from nuclear weapons testing remain in the environment?

  They are released into the environment for decades
• What is the second man-made source of background radiation?

  Nuclear accidents
• What happened at the nuclear power station in Japan in 2011?

  A tsunami caused a release of radioactive isotopes
• How does location affect exposure to background radiation?

  Some areas have higher natural radiation levels
• Which occupations may experience higher levels of cosmic radiation?

  Cabin crew and airline pilots
• How is the dose of radiation measured?

  In sieverts (Sv)
• What is 1 millisievert (mSv) in sieverts (Sv)?

  1 mSv is 0.001 Sv
• What are the two natural sources of background radiation?

  • Radioactive rock (e.g., granite)
  • Cosmic rays from space
• What are the two man-made sources of background radiation?

  • Fallout from nuclear weapons testing
  • Nuclear accidents
• How does background radiation exposure vary among individuals?

  • Depends on location (e.g., granite areas)
  • Depends on occupation (e.g., airline pilots)