Electric & magnetic fields

Electric and magnetic fields in and around the home can be produced by anything with electric current flowing through it, including nearby powerlines, your home wiring system or electrical appliances.

Powerlines generally contribute little to the electrical fields that can be measured inside a house or office. This is because the walls of the building, in fact any solid object, create a shield from the electrical field.

A typical house generally shields at least 90 per cent of the electrical fields from outside.

Magnetic fields from powerlines

Magnetic fields associated with powerlines depend on the amount of current flowing and the distance from the powerline. Fields rapidly decrease in strength with distance, therefore inside a house, magnetic fields from nearby powerlines are usually similar to that from wiring and appliances. In many cases, high voltage lines are constructed on easements where building is not permitted.

Energex recognises the community concern about the potential health impacts of electric and magnetic fields (EMFS).  We rely on expert advice from health authorities in Australia and around the world to ensure that we as a business, practise prudent avoidance when designing South East Queensland’s electricity network.

Industry expertise

The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) is the Australian Government’s primary authority on radiation protection and nuclear safety. ARPANSA undertakes research, provides services, and promotes national uniformity and the implementation of international best practice across all jurisdictions

The Energy Networks Association (ENA) is the National Industry Association representing the businesses operating Australia’s electricity transmission and distribution and gas distribution networks

What is Energex’s response to EMF?

As an Energy Networks Association (ENA) member, we adopt an approach of prudent avoidance. This involves designing, locating and operating electricity assets to minimise field strengths and offer the best value to electricity users.

  • we operate all powerlines and substations in our distribution area within current Australian standards.
  • we conduct our own monitoring and analysis of EMF levels associated with our network in South East Queensland.
  • we maintain contact with a number of bodies and committees which regularly meet to discuss and evaluate any new research into EMF.

Where can I find more information on EMF?

Detailed information on electricity and health can be found on the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) and Energy Networks Association (ENA) websites.

The following table shows typical magnetic field strengths from a number of common sources, including powerlines. Fields are measured in a unit 'milligauss'. To give you an idea of the relative strength of EMFs, the following guide shows the typical magnetic fields from appliances and under powerlines.

Common sources of EMFTypical measurement
(in milligauss)
Range of measurements
(in milligauss)
Electric stove62-30
Personal computer52-20
Television10.2-2
Electric blanket205-30
Hair dryer2510-70
Fridge22-5
Toaster32-10
Kettle32-10
Pedestal fan10.2-2
Distribution powerlines
(under line)
102-20
Distribution powerlines
(8 metres away)
20.4-4
33 kV underground cables
(directly above buried cable)
12
(1 metre above ground)
3
(4 metres away)
Pad mounted distribution transformer2
(at 5 metres)
1-20
(10 metres to close up)
Major zone substation2
(at substation fence)
1-6
(at substation fence)
Modular substation1.5
(at substation fence)
0.5-3
(at substation fence)
Transmission powerlines
(under line)
2010-200
Transmission powerlines
(at edge of easement)
102-50

Note:

Appliance measurements taken at normal user distance. Variations in the design of electrical appliances and the loadings on powerlines can cause magnetic field levels to vary. The table above is based on consistent measurements undertaken by power authorities in Australia, using similar techniques and protocols used overseas. Because of the difference in appliance design and voltage overseas, there can often be different levels shown in overseas publications.