There are no real substantive studies by unbiased and independent sources providing guidance either way. In general it would really depend on how far from the transmission lines you are, what you planned to do in the home, etc., etc. Leaving any potential health issues aside you would also need to consider other situations as well. For example the potential electromagnetic interference (EMI) they can present to radio frequency (RF) devices as well as other electronics in the home. Unless you are a Ham Radio Operator, experiment with various RF devices or even use them in the home it is generally not a problem. Most homes I have seen with high power transmission lines were far enough away from them to present little problem. Although I have seen one home that was amazingly close and it surprised me they allowed it to be built there.
You have an obvious concern and should direct it to a specialist who deals with measuring the effects of Electromagnetic Fields (EMF) as well as their effects. There are those out there that do specialize in this. Here is the WEB site for one such person http://www.scantech7.com/.
They are located in the Dallas/Fort Worth area but can direct you to others in your area as well as other resources to read up on the subject.
Emmanuel J. Scanlan
PS Inspection & Property Services LLC
TREC License # 7593
International Code Council, Residential Combination Inspector #5247015-R5 (Electrical, Mechanical, Plumbing and Building)
Certified Level I Thermographer (ASNT-TC1A Standards)
Texas Residential Construction Commission, Third Party Warranty Inspector #1593
Texas Residential Construction Commission, Inspector, County Inspection Program
Texas Department Of Insurance, VIP Inspector # 08507061016
Hayman Residential Engineering Services, Field Technician
CMC Energy - Certified Energy Auditor
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