There isn't a definitive answer as to health. But there are answers as to the impact on sales. Here's one site to read. http://www.ehow.com/list_7449879_risks-living-near-power-lin
Perception and motivation are linked.
The lastest word I've heard, is that no one can tell! Nothing definitive! No concensus! Nobody agrees!
I would bet that if it was dangerous, there would all kinds of proof and law suits.
You'll have to go with your gut on this.
Good luck and may God bless