Dangers of EM Waves (Oxford AQA IGCSE Physics)

Dangers of EM Waves

• In general, electromagnetic waves become more dangerous the shorter their wavelength

• The main risks associated with electromagnetic waves are summarised in the table below:

Dangers of EM Waves Table

Ionising Radiation

• Radiation from radioactive emissions and short wavelength regions of the electromagnetic spectrum can ionise atoms

  • This is referred to as ionising radiation 

• Beyond the visible part of the spectrum, the energy becomes large enough to ionise atoms

• As a result of this, the danger associated with EM waves increases along with the frequency

  • The shorter the wavelength, the more ionising the radiation

  • Although the intensity of a wave also plays an important role

• In general, electromagnetic waves become more dangerous the shorter their wavelength

  • For example, radio waves have no known harmful effects whilst gamma rays can cause cancer and are regarded as extremely dangerous

• Because of ionisation, ultraviolet waves, X-rays and gamma rays can have hazardous effects on human body tissue

  • The effects depend on the type of radiation and the size of the dose

• Ionising radiation can interact with atoms, damaging cells by the energy they carry and causing mutations, making them cancerous

Ionising regions in the electromagnetic spectrum

• Because of the harmful effects of ionising radiation, safety precautions must be taken during exposure

  • UV protection (sun lotion) should be worn to protect skin from harmful ultraviolet radiation when out in the sun

  • Time limits should be adhered to when using UV tanning beds, along with goggles to protect eyes from damage

  • Film badges should be used for people who work with X-rays to monitor exposure levels

  • Lead aprons or vests should be worn by people having X-ray scans

  • Gamma rays for cancer treatments should be aimed at the target from different directions to minimise exposure to healthy tissues