Differences between ELF and RF EMFs

This website deals with power-frequency EMFs.  The scientific term for these EMFs is “Extremely Low Frequency” (ELF).

At much higher frequencies, EMFs are described as “radiofrequency” or RF.  This website doesn’t cover RF fields.  But we provide a page of links to organisations that do cover RF EMFs.  And here we summarise some of the key differences.

Power-frequency EMFs Radiofrequency EMFs
The frequency is 50 hertz (60 hertz in the USA) and harmonics The frequency is hundreds of kilohertz upwards, all the way up to tens of gigahertz – millions or tens of millions times higher than power frequencies
They are produced by mains electricitypower lines, substations, electricity in the home, appliances They are produced by many different technologies – broadcast TV and radio, cell phones and other radio communications, wi-fi, wi-max, Tetra, etc etc
There haven’t been many major changes in the technologies producing them for many decades The technologies are changing all the time
The electric and magnetic fields are separate phenomena The electric and magnetic fields are coupled together as radiation
They can induce currents in the body but do not cause heating They can cause heating in the body
They tend to be relatively straightforward waveforms (a sine wave with only a few harmonics) The modulations used to transmit signals mean the waveforms are highly complex


There are some similarities as well though:

  • neither causes ionisation in body tissues
  • both are the subject of exposure limits
  • both have been classified by IARC as “possibly carcinogenic”, though based on completely different bodies of evidence
  • both are now inextricably linked with modern societies and lifestyles