Hazards of Contamination & Irradiation (AQA GCSE Physics Combined Science): Revision Notes

4.2.8 Hazards of Contamination & Irradiation

Irradiation and Contamination

Risks

• Radiation can enter living cells and ionise atoms within them. This can damage the cells (which can cause things like cancer).

Irradiation

Definition:

• Exposure to radiation.
• Irradiating something does not make it radioactive.
• Reducing Effects of Irradiation:
  • Keep sources in lead-lined boxes.
  • Stand behind barriers.

Contamination

Definition:

• When unwanted radioactive atoms enter into or onto an object.
• These atoms decay, releasing harmful radiation.
• Preventive Measures:
  • Gloves and tongs (prevent contact with skin).
  • Protective suits (prevent inhalation).

Irradiation and Contamination

General Information

• Radiation can be ionising:
  • It can form ions.
  • Ionising radiation can increase the risk of cancer in humans.

Irradiation

Definition:

• Exposing an object to nuclear radiation.
• Gamma radiation kills any bacteria present (e.g., needles).
• Characteristics:
  • The object does not become radioactive because it only comes in contact with the radiation, not the radioactive isotope.
• Risks:
  • Ionising radiation can increase the risk of cancer.
• Precautions:
  • People who work with radioactive isotopes have to take precautions.
  • Shielding:
  • Gloves can protect against alpha radiation.
  • Lead aprons for beta and gamma radiation.
  • Lead walls, lead glass screens.
  • Monitoring:
  • A radiation monitor measures how much radiation has been received.
  • If a person has received too much radiation, they must stop working with radioactive isotopes.

Radioactive Contamination

• Hazards:
  • This is hazardous as the radioactive atoms decay and emit ionising radiation.