极低频电磁场(Extremely low frequency electromagne ticfields,ELF-EMF)指频率为0～300Hz的交变电磁场。电场强度随电压或电势的升高而增强,磁场强度随电流的升高而增强,两者都随距离发生源的远近而迅速变化。电场很容易被建筑物遮挡,其穿透能力很弱。相比而言,穿透能力很强,即使被建筑物遮挡也不容易减弱,因此人们更关心磁场对健康的影响。 Extremely low frequency electromagnetic fields (ELF-EMF) refer to alternating magnetic fields with frequencies of 0-300 Hz. The electric field intensity increases with the increase of voltage or potential, and the magnetic field intensity increases with the increase of current, both of which change rapidly with the distance from the source. Electric field is easily blocked by the building, its penetration is very weak. In contrast, the penetrating power is so strong that it is not easily weakened even if it is blocked by buildings. Therefore, people are more concerned about the health effects of the magnetic field.