Residential exposure

New Australian study investigates magnetic field exposures in homes

Australian investigators have shown that high magnetic fields are often found in residences, whether or not they’re located close to high voltage power lines.

In a study published in the journal Measurement Dr Malka Halgamuge and Lyn McLean, report on electromagnetic fields present in a hundred Australian homes.

‘Our results show that high magnetic fields are often present in typical homes,’ said Dr Halgamuge, a lecturer in electrical engineering at the University of Melbourne. ‘They can be present from microwave ovens, conductive water pipes, meter boxes, and wiring, as well as external sources such as power lines, transformers and substations.’

The study analysed 3163 measurements of magnetic fields from 100 houses in different parts of Australia and provides data for appliances, different locations, conductive plumbing and other sources. It found that fields of above 4 milliGauss – a level classed as a possible carcinogen by the IARC – were present in many situations, with the potential of exposing residents in high-use locations such as beds.

The results also showed that some brands of appliances generated much higher magnetic fields than others, suggesting that appliances can be designed in ways that reduce exposure to users.

‘Our results highlight the importance of measuring fields in every home,’ said Lyn McLean, Director of EMR Australia PL. ‘That way people can identify the magnetic fields that are present and take steps to reduce their exposure.’

Reducing exposure is a common-sense approach to dealing with potential risks and is in line with every-day precautions such as wearing seat belts, installing pool fences or warning signs for slippery floors and with policies for wearing sun hats in schools, the authors say.

Halgamuge and McLean suggest that some of the ways that exposure can be reduced are as follows.

Bedrooms

  • Measure magnetic fields in a room before positioning a bed.

Ensure that beds are located away from meter boxes, the back of a fridge (where fields are higher), conductive plumbing and wiring configurations that produce high · fields.

  • Keep sources of high fields – such as transformers, electrical cables, clock radios and televisions – away from beds.
  • Use electric blankets to warm the bed and then turn them off at the power point before sleeping.

Study

  • Keep the screen and hard drive of a Personal Computer (PC) and transformers a distance from a user’s body.
  • Avoid using laptops on the lap.

Kitchen

  • Position appliances with high fields away from locations where people spend time, such as food preparation benches or eating areas.
  • Prepare food on benches that are located away from appliances that are operating, including microwave ovens, even when they are not operating.
  • If a microwave oven is located near a high-use area, turn it off at the power point when it is not being used.

Loungeroom/family room

  • Measure fields before locating furniture where people will spend time, such as lounges, chairs and tables.

Laundry and bathroom

  • Hold hairdryers away from the scalp when drying hair.
  • Professional hairdressers should avoid holding hairdryers near foetal position when pregnant.
  • Manufacturers can design hairdryers to minimise users’ exposure at the handle and head.
  • Sensitive people could wait till irons reach desired temperatures before commencing ironing.

Other appliances

  • Select new appliances – especially those to be used in close proximity to the body – that have minimal magnetic fields. For example, digital clock radios, which are often located next to the bed, have high magnetic fields, whereas battery operated clocks have no alternating magnetic field.
  • Manufacturers should design appliances so that fields are low at the positions closest to the body.

Workers and employers can:

  • keep workstations a distance from sources of high magnetic fields, such as photocopiers, transformers, electrical cables and power lines (especially on the second-storey of a building);
  • design appliances to minimise magnetic fields, eg locating the motor away from parts of the appliance operated close to the body;
  • provide information about the magnetic fields emitted by workplace equipment;
  • develop policies to limit unnecessary exposure to workers.

Planners and builders can:

  • position meter boxes away from bedroom walls, preferably on the wall of a garage or cupboard;
  • keep high-current electrical cabling away from sleeping and living areas
  • install wiring so that the active and neutral wires are run close together to minimize magnetic fields;
  • locate buildings away from high voltage (above- or underground) power lines.

Halgamuge, MN and McLean, L, ‘Measurement and analysis of power-frequency magnetic fields in residences: Results from a pilot study’, Measurement 125:415-24, 2018.

From EMR Australia’s ‘EMR and Health’ 14(3), Jun, 2018.

https://www.sciencedirect.com/science/article/pii/S0263224118303920
Back to Blog