Power lines and sub stations not responsible for all high domestic magnetic fields

A recent survey and study of the sources of magnetic fields in the home has
found that less than 2.5% of UK homes have background magnetic fields above
0.2µT (microtesla) associated with the electricity power supply, and most of
these are not close to major power lines or electricity substations.

The Radiation Protection Division of HPA carried out this study on behalf of
the Leukaemia Research Fund (Epidemiology and Genetics Unit, University of
York) which was funded by the Department of Trade and Industry and the Energy
Networks Association.

Investigation and Identification of Sources of Residential Magnetic Field
Exposures in the United Kingdom Childhood Cancer Study (UKCCS) studied sources
of power frequency magnetic fields associated with nearly 200 homes identified
from the UK Childhood Cancer Study (UKCCS) and found that:

  • the most common source of magnetic field exposure above 0.2µT in homes arose
    from currents in the supply to the home and possible wiring faults (32%);
    followed by nearby high voltage power lines of 132kV and above (20%);
  • the effect of currents in low voltage distribution mains cables located near
    to homes (16%), (often characterised by little or no front garden and closer to
  • the other individual sources identified were 275kV cables, low voltage
    overhead lines, electrical appliances and a nearby electrified train line;
  • the magnetic fields in the remaining homes were due to a possible combination
    of low voltage sources;
  • of 21 homes with exposures of 0.4 µT and above, the most common single source
    was high voltage overhead lines (43%), followed by currents in the supply to
    the home and possible internal wiring faults (33%); the various low voltage
    sources taken together accounted for 57% of the exposures.

Most UK homes have background magnetic fields in the range 0.01 to 0.1 µT and
less than 2.5% have levels above 0.2 µT.

Further Information

AplusA-online.de - Source: Health and Safety Executive (HSE)