Objective To investigate residential power-frequency electromagnetic field exposure in Baoshan District, Shanghai.
Methods A total of 160 residential households were selected and the intensity of power frequency electromagnetic field were recorded at various spots in residential households with household appliances on and off.
Results In the state of appliances disconnected from power line, both the intensities of power-frequency electric field and the magnetic field in the houses within 100 m range to high voltage lines were significantly higher than those in the houses having more than 100 m gap to high voltage lines. Compared with the house beyond 100 m range to high voltage lines when appliances were on, there were no significant difference in the intensities of power-frequency electric field in the houses within beyond 100 m range to high voltage lines but the in tensities of power-frequency magnetic field were significantly higher which suggested a distance-dependent manner. No matter the on/off state of the household appliances, the intensities of power-frequency electric field and magnetic field were both higher than the background electromagnetic radiation of Shanghai, although they were far below the limits of national standards. In addition, the in tensities of power-frequency electric field at the center of the houses were higher than those off-center spots but no such pattern observed in the magnetic field measurement.
Conclusion The residential power-frequency electromagnetic field levels in current study are higher than local background level and both far from the related national standards.
DownLoad: