I used to work on high voltage systems but I'm alright noooOWWW. (Ok, I did. We supplied at 6.6KV down our pit when I was an electrician there and when I worked on the pit top, one winding house had an 11KV motor. Serious stuff.....)

Seriously, there may be long term issues, and there may not be. I am aware that there are very long term clinical studies being carried out in a number countries on this and other RFI type issues such as mobile phone masts, microwave repeater towers and TV transmitters.

The UK has laws governing exposure of magnetic flux and radio waves in clinical settings, (covering X Ray, scanners, ultrasound etc) and if anybody is interested, the regs are called The Ionising Radiation (Medical Exposure) Regulations 2000, (IR(ME)R 2000.)

These ensure nobody has unnecessary exposure in a medical setting. Now, I am sure there are good reasons why exposure levels are set in law, and the background to the tolerance levels may have a bearing on this discussion. However, the strong local exposure through, (to give the best comparison) MRI scanners will be umpteen times as powerful as living near a pylon. However, for a much shorter sustained period.

Interesting stuff. I assume it will be some time before the long term studies can give us anything conclusive but I don't see it as an issue till told otherwise, my take on it.