24 Hour recording of a (50 Hz or 60 Hz) magnetic field strength radiated by a 400 000 v high-voltage power line

A few reminders:

  • 400 000 v high-voltage lines are strong emitters of electric fields but particularly of magnetic fields

  • The radiation strength of a (50 Hz or 60 Hz) magnetic field is directly proportionate to the amount of electrical current being consumed on the line.

  • The higher the current consumption (the use of heating in winter, air-conditioners in summer), the stronger the magnetic field. This increases the exposure of local residents.

  • The most critical moments are therefore winter cold spells and heatwaves (air-conditioning systems).

Emission strength around high-voltage lines depends not only on the period of the year but also on the time of the day

The strength of the radiated magnetic field varies according to the period of the year and the time of the day as shown in a recording that I carried out using a Gigahertz NFA 1000 measuring device.


Recording carried out during a summer heatwave (3 August 208) using the Gigahertz NFA1000 at a 20m distance from a 400 000 v power line.

Recording carried out during a winter cold spell (February 2018)using the Gigahertz NFA1000 ata 20m distance from a 400 000 Volts power line.

24 hour average 2123 nT (nano Tesla)

The Bioinitiative standard advocates a permanent maximum exposure limit of 50 nT in the home.

24 hour average 2256 nT (nano Tesla)

The Bioinitiative standard advocates a permanent maximum exposure limit of 50 nT in the home.

effet du champ magnétique sur la santé
    • According to the two magnetic field recordings, we can see that the electrical consumption is practically identical during a summer heatwave or a winter cold spell.

    • Exposure of local residents to the (50 Hz or 60 Hz) magnetic field of high voltage power lines is maximum at these periods of the year.

    • A peak in the consumption of electricity can be seen from 23H. The setting off of off-peak hour systems for water heaters, washing machines and washing-up machines.

How to protect yourself from the permanent magnetic field ?

Walls do not act as a barrier to a (50 Hz or 60 Hz) magnetic field (no attenuation)

The installing of sheeting (Mumetal) in homes to efficiently attenuate magnetic field radiation from a high-voltage power line is both a costly solution and difficult to implement.

The only real form of protection from a magnetic field is to remain at a distance.

It is advisable to live at a distance of at least 400 meters from a 400 000 v power line to permanently benefit from a reasonable below-the-threshold exposure limit (according to the standards advocated by Bioinitiative 2012). The Bioinitiative standards advocate a maximum permanent exposure level of 50 nT in the home.