Dangers of Electromagnetic Waves (Cambridge (CIE) O Level Physics): Revision Note

Dangers of Electromagnetic Waves

• As the frequency of electromagnetic (EM) waves increases, so does the energy

• 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 a very important role

Ionising Region of Electromagnetic Spectrum

Ultraviolet, X-rays and gamma rays can all ionise atoms

• 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

• They can damage cells and cause mutations, making them cancerous

• 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

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

Dangers of EM Waves Table