There are indications from epidemiological research that long-term exposure may be associated with a mildly elevated risk of leukaemia in children. For that reason, the International Agency for Research on Cancer (IARC) has classified low-frequency magnetic fields (originating from the electric power grid) as ‘possibly carcinogenic to humans’. ‘Long-term exposure’ refers to a long-term stay in places where the average magnetic field over 24 hours is higher than 0.3 – 0.4 µT, which could be the case near high-voltage power transmission lines.

The classification ‘possibly carcinogenic to humans’ is assigned to environmental factors and substances that show ‘limited epidemiological evidence’ in connection with cancer. As for 'limited indications', it is still possible that the connection is only apparent and that a coincidence or misrepresentation falsifies the results. The level of certainty when something is classified as 2B ('possibly carcinogenic in people') is lower than in the case of classification 2A ('probably carcinogenic') and 1 ('carcinogenic').

How great is the risk?

Childhood Leukaemia appears in 3 children in 100,000 each year. There are various risk factors that can increase the chance of developing childhood leukaemia, for example, ionising radiation (such as x-rays), genetic factors, household use of pesticides and certain solvents in paint, smoking and possibly alcohol use by the mother during the pregnancy.

If it should emerge from further investigation that ELF magnetic fields also belong on the list of risk factors, this factor would be responsible for less than 1% of the childhood leukaemia cases each year (in the Flemish region), according to the Superior Health Council.

Recommendation of the Superior Health Council

Although there is still much uncertainty regarding the precise role of magnetic fields in increasing the risk of childhood leukaemia, the Superior Health Council (advice no. 8081) recommends that children under the age of 15 not exceed the exposure limit of 0.4 µT (averaged over a long period).

This means that the home and in particular the bedroom should ideally be at a sufficient distance from electrical installations such as high-voltage power lines, distribution lines and substations. In addition, the bedroom and particularly the child’s bed should be placed at a sufficient distance from the home’s electrical installations (distribution board and wires, electric under-floor heating) and continuously operating devices (electric blankets, electric alarm clocks).

The table below provides an approximation of the distances to be maintained.

Installation Type Distance
1. Overhead high-voltage line70 kV 30 m
150 kV 45 m
220 kV 60 m
380 kV 100 m
2. Underground high-voltage cable36 kV   4 m
70 kV 5,5 m
150 kV 7,5 m
3. Medium- and low-voltage line Immediate surrounding (0.5 m)
4. Transformers From 30 kV towards 10 to 15 kV8 m
From 10 to 15 kV towards 220 to 400 V5 m
5. Installations in the residence
• Distribution cables for different residences (e.g. apartment buildings)
• Distributing board and meter for domestic use
• Electrical floor heating
Immediate surrounding (0.5 m)
6. Electrical devices, only:• Radio alarm clock
• Electric blankets 0.5 m
0,5 m

You can download all information of the section "Electricity" in its entirety as a PDF document (information sheet “Electricity and health”).