Exposures to power-frequency magnetic fields in the home

Abstract
Power-frequency magnetic fields in homes come from a variety of sources, internal (appliances and domestic wiring) and external (electricity distribution and transmission circuits). The authors present results from a survey of the fields encountered at home by 258 adults over one week each. Information on the major electrical features of each of the homes was collected and related to the exposures incurred. The strongest identified factor influencing exposure at home was the presence or absence of overhead lines at voltages of 132 kV or above within 100 m of the home (geometric-mean TWA field encountered by participants 208 nT near lines, 54 nT not near lines). Occupants of homes near overhead lines or supplies from 415 V to 66 kV did not on average encounter fields significantly different to those in homes without such lines (50 and 54 nT, respectively). Occupants of flats incurred greater exposures than those incurred by occupants of semi-detached and terraced houses, which were in turn greater than those incurred by occupants of detached houses (109, 60, 56 and 43 nT, respectively).