UV

• What is the definition of radiation?

  Energy in the form of waves or particles
• What is the international symbol for radiation?

  The "tri-foil" symbol
• What colors can the radiation symbol be?

  Magenta or black on yellow
• Where is the radiation symbol posted?

  Where radioactive materials are handled
• What are the two main classifications of radiation?

  Ionizing and non-ionizing radiation
• What is ionizing radiation?

  Higher energy waves that can dislodge electrons
• What is non-ionizing radiation?

  Lower energy waves that cannot dislodge electrons
• What is the definition of ionizing radiation?

  Radiation that disrupts atoms and molecules
• What are the primary types of ionizing radiation?

  Gamma rays, X-rays, and neutrons
• What are the three types of radiation that can kill microbes?

  1. Ionizing Radiation

  • Gamma rays, X-rays, electron beams
  • Short wavelengths (less than 1 nanometer)
  • Causes mutations in DNA

  1. Non-ionizing Radiation

  • Ultraviolet light
  • Longer wavelengths (greater than 1 nanometer)
• How does ionizing radiation affect DNA?

  It causes mutations and produces peroxides
• What is a disadvantage of ionizing radiation?

  It penetrates human tissues
• What is a disadvantage of non-ionizing radiation?

  It damages skin and eyes
• What type of damage does ultraviolet light cause?

  It produces thymine dimers in DNA
• What is the wavelength range of ultraviolet radiation?

  Between 40 and 400 nm
• What is the primary natural source of UV radiation?

  The sun
• What is UVC radiation used for?

  To kill bacteria with germicidal lamps
• What are the harmful effects of UVB radiation?

  Sunburn, cataracts, skin cancer
• What is UVA radiation commonly associated with?

  Tanning and skin darkening effects
• What is the wavelength range of microwave radiation?

  From 1 millimeter to 1 meter
• How does microwave radiation kill microbes?

  By heating water molecules in food
• What is a limitation of microwave radiation?

  Bacterial endospores are not damaged
• What health risk is associated with microwaved pork?

  Trichinosis outbreaks
• What are the differences between ionizing and non-ionizing radiation?

  • Ionizing Radiation:
  • Higher energy
  • Can dislodge electrons
  • Causes DNA mutations
  • Non-ionizing Radiation:
  • Lower energy
  • Cannot dislodge electrons
  • Can excite electrons
• What is the effect of UVC radiation on humans?

  It can cause corneal burns
• What is the effect of UVB radiation on humans?

  It can cause sunburn and skin cancer
• What is the effect of UVA radiation on humans?

  It can suppress the immune system