In the domain of field characterization,
magnetic fields in the vicinity of power facilities have been extensively surveyed in recent years and sources generating a substantial magnetic field have been identify.
These are under ground cables, overhead transmission and distribution lines, underground structures, sub-stations and other individual power system equipment. Their typical values were found to be in the range of a few mG up to a few hundreds of mG in living and working places.
These values are generally higher than the magnetic field levels identified in epidemiological studies