Electric and magnetic fields
Electricity is first transmitted from the power plant to the consumer over high-voltage transmission lines (400, 220 and 110 kV in Finland), then by means of medium-voltage overhead lines and cables (50, 20 and 10 kV) and finally by low-voltage wiring (0.4 kV). transmission lines generate electric and magnetic fields in their surroundings.
On 12 July 1999, the Council of the European Union published a recommendation on limiting the exposure of the population to electric and magnetic fields. The aim of the recommendation is to protect the health of citizens from the direct health effects of the fields. The decree of the Ministry of Social Affairs and Health (STM) that came into force on 15 December 2018 is based on this recommendation.
In accordance with the decree, the action level for restricting the exposure of the population to low-frequency magnetic fields generated by transmission lines is 200 microtesla (µT).
The decree shall not be applied to the threshold values for the electric fields of transmission lines, as provisions have been set out under the Electrical Safety Act on transmission lines which, when adhered to, guarantee that the strength of an electric field in the vicinity of a transmission line is at a safe level.
The Ministry of Social Affairs and Health has published a guide on public exposure to low-frequency electric and magnetic fields in Finland (Ministry of Social Affairs and Health Guides 2003:12), comprising an information package on the electric and magnetic fields of electricity transmission and distribution systems.
Transmission lines are designed and constructed in such a way that the values specified in the recommendation of the Council of the European Union and the decree of the Ministry of Social Affairs and Health are not exceeded.
General information on the subject, collected by Fingrid, is presented in the position paper on electric and magnetic fields of the transmission lines of the main grid. Read the position paper here. You can also find the attachment on the right under Additional information.
Potential health effects
The studies have also addressed the issue of a possible link between magnetic fields and health aspects such as cancer diseases.
Tampere University of Technology has prepared a brochure on the electric and magnetic fields of transmission lines and their possible health effects.
Fingrid also monitors new research findings relating to the health effects of electric and magnetic fields. Since 2009, we have worked in co-operation with professor Leena Korpinen, publishing situation reports a couple of times a year, discussing medically-focused research related to electric and magnetic fields that are of particular interest from the perspective of population exposure.