Transmission lines mostly use three phase alternating current (AC),
Electricity is transmitted at high voltages (110 kV or above)
![](http://upload.wikimedia.org/wikipedia/commons/6/66/Electric_transmission_lines.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/c/cf/Electicaltransmissionlines3800ppx.JPG/800px-Electicaltransmissionlines3800ppx.JPG)
看看這家就在高壓線旁
![](http://siliconvalleyrealestateinfo.com/wp-content/uploads/2008/01/powerlnsmall.jpg)
其它的你看到的可能不是高壓線
讀讀這篇文章很好:
http://www.siliconvalleyrealestateinfo.com/2008/01/03/electric-and-magnetic-fields-emfs-and-how-they-effect-real-estate-prices/