Electromagnetic fields (EMFs)

What are electromagnetic fields (EMFs)?

Low frequency electric and magnetic fields (EMFs) are invisible lines of force around any electrical device. They are around all wires that carry electricity. You would find them around your television, kettle, house wiring and also in the power lines and cables that supply power to your house. 

Mobile phones, photocopiers and some medical equipment also produce EMFs, but these emissions differ to those caused by electrical wires.

About EMFs

  • EMFs from most home appliances are low, as they usually operate at low voltage. The solid objects in your home also shield or weaken electrical fields. For example, a typical house shields at least 90% of the electrical fields found outside. Magnetic fields are not necessarily shielded.

  • generally, EMFs found within 30cms of a home electrical appliance exceed the EMF levels caused by power lines on a typical street.

Health effects of EMFs

To date, results of scientific studies on the health effects of EMFs are varied and inconclusive. Very limited evidence supports a link between magnetic fields and childhood leukaemia and there is no evidence of any other adverse health effects. In the two decades since the link between electricity lines and health was first raised, extensive research has given limited answers. While future studies may help, it is possible that the very low levels of potential risks and overall exposures will mean that an absolute answer may not be possible.

Despite little evidence of any health risk, there is significant community interest in EMFs and we:

  • maintain contact with bodies that regularly meet to review the latest EMF research

  • operate a free testing service for anyone who has concerns about EMF levels on their property

  • provide free advice on how to minimise EMF levels in homes and businesses

  • monitor EMF levels around our network

  • operate all power lines and associated equipment within national guidelines.

For testing and advice about EMFs, please contact us on 03 363 9731 or email us.

A booklet on "Electric and magnetic fields and your health" is available from the Ministry of Health website.

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