Chuck: There is a comprehensive review and assessment of studies on this subject presented in the Oct. 1995 issue of the IEEE Spectrum.... probably the most trustworthy survey source for this type of information.
The EMC Society Newsletter (issue #168, winter 1996) had a brief comment on a 10-year study conducted by the National Council on Radiation Protection and Measurements that recommended housing, schools, etc. not be built under power lines IF FIELDS EXCEED 0.2 microtesla. National Geographic did a 1-hour special that essentially said "no problem," "inadequate correlation," and criticized the multi-billion dollar impact such unfounded fears have had on the US economy to date. I have lived under power lines for the last 20 years with no reports of my neighbors having any negative effects. In fact, I have measured the fields in and around my home (which is centered about 70 feet off the axis of the high voltage lines supplying the substation that is approximately 100 feet from my house). I found the fields OUTSIDE to be well under 0.1 microtesla; however, I measured many locations over a HUNDRED times higher INSIDE the home. Areas near refrigerators, fluorescent lights, clock radios, etc. ALL produced fields much greater than those generated by the outside power lines. The relative placement of the power lines on the support structure to achieve field cancellation is probably most important in providing compatibility of power distribution systems. It seems the housing construction standards (and perhaps electric appliances) are far more in need of the public's concern about the biological effects of low-frequency magnetic fields. Mike Conn Owner/Principal Consultant Mikon Consulting