Electric Power Facilities

Electricity is generated at various types of power stations including “nuclear power stations”, “thermal power stations”, “hydro power stations”, “wind power stations” and “photovoltaic stations” etc. It is then transmitted to homes and factories via transmission lines, substations and distribution lines. The collective term for these structures is referred to as “electric power facilities”.

Features of Electromagnetic Field Generated from Electric Power Facilities

The strength of electromagnetic fields (specifically the magnetic field) generated from electric power facilities relies on “magnitude of the electric current” passing through the facilities and “distance from the sources”.

The strength of magnetic field increases with the magnitude of electric current and decreases rapidly as the distance from the sources increases (inversely proportional to the square or cube of the distance).

Strength of Magnetic Field Generated from Electric Power Facilities

In Japan, a regulation has been implemented regarding electric power facilities to protect general public from health effect of short-term exposure to magnetic field. The levels of magnetic fields generated from electric power facilities are as shown in the following figure. The reference levels recommended by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines for 50/60 Hz MFs is 200 µT (micro-tesla). This reference value is significantly higher than that emitted by home appliances used in our daily lives.

Scientifically Established Effects of Magnetic Fields on Humans

Magnetic fields generated from electric power facilities and encountered in our living environment do not affect humans. Even when exposed to very strong magnetic field, several hundred times more than those typically encountered in living environment, due to the phenomenon called electromagnetic induction may occur, potentially hindering the activities of nerves and muscles. And much stronger magnetic fields have been identified to impact the functioning of the heart. For further details, please refer here.

For scientifically unestablished effects (effect from long-term exposure), please read here.