irradiation and contamination

• Irradiation


  Process of exposing an object to a source of radiation
• Contamination


  Occurs if a radioactive source is on or in an object
• Irradiation


  Doesn't cause the object to become radioactive
• Contamination


  The contaminated object will be radioactive for as long as the source is on or in it
• Irradiation


  Can be blocked with suitable shielding or moving away
• Contamination


  Once an object is contaminated, the radiation cannot be blocked from it
• Irradiation


  Stops as soon as the source is removed
• Contamination


  It can be very difficult to remove all of the contamination
• Irradiation uses


  • Preserving fruit by exposing it to a radioactive source like Cobalt 60
  • Sterilising surgical instruments
• Contamination uses


  • Doctors can deliberately contaminate a patient's body to help with diagnosis, e.g. drinking a radioactive mixture (barium meal) or introducing technetium-99 into the body
• Irradiation and contamination are different processes