Lecture Notes: Irradiation and Radioactive Contamination

Objectives

• Understand the concepts of irradiation and radioactive contamination.
• Describe the hazards associated with each.
• Learn the precautions to take against these hazards.

Key Concepts

Background on Radioactive Isotopes

• Radioactive Isotopes: Emit radiation as they decay.
• Ionizing Radiation: Can create charged atoms (ions) and increase cancer risk.

Irradiation

• Definition: Exposing an object to nuclear radiation (alpha, beta, gamma, or neutrons).
• Example: Sterilization of medical equipment using gamma radiation.
  • Objects like syringes are sterilized without heating by exposing them to gamma radiation.
  • Gamma radiation kills bacteria, but the object remains non-radioactive as it is not in contact with the radioactive isotope.
• Precautions:
  • Shielding: To stop radiation exposure.
    • Alpha Radiation: Stopped by gloves.
    • Beta & Gamma Radiation: Require lead aprons or specialized protective setups.
    • High Radiation Levels: Use lead walls or screens with lead-containing glass.
  • Radiation Monitors: Measure exposure to ensure safe levels.

Radioactive Contamination

• Definition: Unwanted radioactive isotopes on materials.
• Hazards:
  • Radioactive atoms decay and emit ionizing radiation.
  • With contamination, the radioactive source is on/in you.
  • Alpha Emitters:
    • Strongly ionizing; dangerous if inhaled or swallowed.
    • Stopped by skin but can damage internal living cells.
  • Beta Emitters:
    • Less ionizing but can penetrate the body.
  • Gamma Rays:
    • Weakly ionizing; pass through the body but usually less hazardous.

Research and Safety

• Peer Review: Critical for verifying scientific research on radiation effects.
• Study Sharing: Ensures accuracy and validity.

Additional Resources

• Revision Workbook: For practice questions on irradiation and contamination.
• Link provided in the lecture for access.

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