Contamination & Irradiation (OCR GCSE Physics A (Gateway Science Suite)): Revision Notes

4.2.7 Contamination & Irradiation

Contamination and Irradiation

Contamination

• Lasts for a long period of time
• The source of the radiation is transferred to an object
  • Radioactive contamination is the unwanted presence of radioactive atoms on other materials – the hazard is the decaying of the contaminated atoms releasing radiation.
  • Example: radioactive dust settling on your skin (your skin becomes contaminated)

Irradiation

• Lasts only for a short period of time
• The source emits radiation, which reaches the object
  • Exposing an object to nuclear radiation, but this does not make it radioactive.
  • Example: radioactive dust emitting beta radiation, which "irradiates" your skin.
  • Medical items are irradiated sometimes to kill bacteria on their surface, but not to make the medical tools themselves radioactive.

Scientific Reports and Peer Review

• Scientific reports published need to be peer-reviewed.
  • If they are on the effects of radiation on humans, peer review is essential.
  • If initial studies got measurements wrong, safety levels based on the study may cause people to die.