As a side note, I was born and raised in Los Angeles and for 22 years our home was in very close proximity to very high tension power lines. I'm fine and still kicking and so are my two sisters and even Mom who is now 87.
Good luck--I hope this is helpful.
I suggest you research it yourself and see what I mean. The studies that we were able to find could not show clear evidence, but there were discussions. Try googling the topic, or put on ask.com and see what they say.
The bigger debate for us was whether you could hear the humming sound emitted. I personally couldn't hear it all even when standing right at the end of the property and listening for it. When asking others, some heard it and some didn't. When someone hears it, they might find it an annoyance.