Electric and magnetic fields
Electric and magnetic fields arise, among other things, when electricity is produced, transported and consumed. They are found almost everywhere in our environment, around both power lines and electrical devices that we use daily at home.
Around an overhead alternate current (AC) line there is an electric and a magnetic field. The voltage between the phases (lines) and the ground causes the electric field, while the current generates the magnetic field.
Svenska kraftnät follows the precautionary principles that the Swedish Radiation Safety Authority recommends together with the Swedish Work Environment Authority, the National Board of Housing, Building and Planning, the Swedish National Electrical Safety Board and the Public Health Agency of Sweden (which took over the responsibilities previously held by the National Board of Health and Welfare).
To clarifyour interpretation of the authorities' recommendations, we have developed a policy for the magnetic field levels around our lines. The authorities have not set any limits regarding magnetic fields. The choice of a precautionary level in our policy is therefore based on the overall research findings available and the recommendations that the authorities have produced.
Svenska kraftnät's magnetic field policy
When planning new lines we must ensure that magnetic fields do not normally exceed 0.4 micro tesla where people permanently reside.
Upon the renewal of concessions for existing lines we must consider measures that reduce exposure to magnetic fields. Measures must be implemented where people are exposed for sustained periods to magnetic fields that deviate significantly from what is normal. A prerequisite is that the costs and consequences are otherwise reasonable.
Implementation of the magnetic field policy
In conjunction with the renewal of permission for our AC lines, we take frequent measures to reduce the magnetic fields or offer to buy buildings that stand as close to the line that the magnetic field exceeds 4.0 μT.
For brand new AC lines our policy is that the magnetic field level must not exceed 0.4 μT where people live or stay permanently.