Aerial view of Brisbane city and the river

Electric & magnetic fields

Electric and Magnetic Fields (EMFs) are produced by any appliance with electric current flowing through it. That includes not only powerlines but just about every electrical appliance used in the house.

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.

EMFs and 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.

We recognise 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 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.

Our 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 address concerns about EMF exposure by:

  • Operating all powerlines and substations in our distribution area within current Australian standards
  • Keeping informed about engineering and scientific research on EMF exposure and reviewing its policies in the light of the most up-to-date research findings, with particular emphasis on the findings of eminent scientific review panels
  • Actively participating in industry and other forums that have the objective of broadening scientific knowledge of the effects of EMFs
  • Responding constructively and consistently to employee and community inquiries and referring inquirers to authoritative sources of information
  • Practising prudent avoidance (as established by good engineering and planning practice as it is applied, or is to be applied, at our operating locations) in siting new generation, transmission and distribution facilities
  • Undertaking monitoring and analysis of EMF levels associated with its network
  • Prudently managing public, and our employees' and contractors' occupational exposure to EMFs associated with our network.

Does undergrounding stop EMFs?

Putting powerlines underground does not stop EMFs. The earth does not shield magnetic fields. Design decisions such as using multiple phases (wires) and laying them closer together underground can help to reduce EMF levels. Importantly, similar design decisions can often be used with overhead wires to help cancel out magnetic fields.

Common sources of EMFs

Detailed information on electricity and health can be found on the ARPANSA and 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 EMF Typical measurement (in milligauss) Range of measurements (in milligauss)
Hair dryer 25 10-70
Electric blanket 20 5-30
Electric stove 6 2-30
Personal computer 5 2-20
Toaster 3 2-10
Kettle 3 2-10
Fridge 2 2-5
TV 1 0.2-2
Pedestal fan 1 0.2-2
Electricity network
Transmission powerlines
(under line)
20 10-200
33 kV underground cables
(directly above buried cable) 
(1 meter above ground)
(4 meters away)
Transmission powerlines
(at end of easement)
10 2-50
Distribution powerlines
(under line)
10 2-20
Distribution powerlines
(8 meters away)
2 0.4-4
Pad mounted distribution transformer 2
(at 5 meters)
(10 meters to close up)
Major zone substation 2
(at substation fence)
(at substation fence)
Modular substation 1.5
(at substation fence)
(at substation fence)

For more information read the Energy Networks Association, Australia, brochure ENA EMF Management Handbook.

Exposure levels

The Energy Networks Association recommends the following limits of exposure:

  • Public exposure to magnetic fields of 200 microtesla (µT)
  • Occupational exposure to magnetic fields of 1,000 microtesla (µT)
  • Public exposure to electric fields of 5 kilovolts per metre (kV/m)
  • Occupational exposure to electric fields of 10 kilovolts per metre (kV/m)


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.