Dangers of Electromagnetic Waves

• Electromagnetic radiation


  Can be harmful to people
• Effects of EM radiation

  1. Enters living tissue

  2. Creates havoc

  3. Based on energy transfer
• Low frequency waves


  • Don't transfer much energy
  • Mostly pass through soft tissue without being absorbed
• High frequency waves (UV, X-rays, gamma rays)

  • Transfer lots of energy
  • Can cause lots of damage
• Harmful effects of UV radiation

  • Damages surface cells
  • Can lead to sunburn
  • Can cause skin to age prematurely
  • Can cause blindness
  • Can increase risk of skin cancer
• Ionising radiation (X-rays, gamma rays)


  • Carry enough energy to knock electrons off of atoms
  • Can cause gene mutation or cell destruction
  • Can cause cancer
• Radiation dose (measured in sieverts) is a measure of the risk of harm from the body being exposed to radiation
• Radiation dose is not a measure of the total amount of radiation that has been absorbed
• Radiation doses can be calculated for all types of radiation, not just UV, X-rays and gamma rays
• The risk depends on the total amount of radiation absorbed and how harmful the type of radiation is
• Sievert


  A large unit, so doses are often measured in millisieverts (mSv), where 1000 mSv = 1 Sv
• Radiation dose from CT scans

  • Head: 2.0 mSv
  • Chest: 8.0 mSv
• If a patient has a CT scan on their chest, they are four times more likely to suffer damage to their genes (and their added risk of harm is four times higher) than if they had a head scan