Tag Archives: Electric

EMF Power Lines & Safe Distance for Protection – What is Wrong with this Picture?

Mark Twain once commented:

“Figures often beguile me,” he wrote, “particularly when I have the arranging of them myself; in which case the remark attributed to Disraeli would often apply with justice and force: ‘There are three kinds of lies: lies, damned lies, and statistics.”

So what is beguiling about this figure?

safe-living-distance-to-power-lines

Deceptive depiction of EMF fields from high voltage powerlines.

It gives greatly oversimplified answers to alleged effects based on solely on DISTANCE instead of actual ELECTRIC OR MAGNETIC FIELD STRENGTH. It is understandable that most clients and residential home owners want a simple formula or guideline to the question “How far or what distance from high voltage power lines is safe, or within safety levels for my family and I?”

Unfortunately, the answer isn’t that simple for the following reasons.

Because of the poor coupling between electric fields and the human body, even strong external AC electric fields have a vanishingly small effect on the voltages induced in the body compared to the bio-electric energies already present in the heart, brain and nervous system. Magnetic fields have a stronger potential for affecting the human organism, but the only parameter mentioned is the 765 kilo-volts present on the line which pertains to the electric field, not the magnetic component which would relate to current measured in amps.

There is also a fine nuance in the graphic itself that most people not familiar with electromagnetic theory would miss. The field is shown as radiating out from three different points on the tower in concentric circles. This is indicative of a magnetic field, not an electric field. The electric field comes straight out of the wire and that is based on voltage which is the only metric given. So the implication is that the main parameter for an electric field is given, but a magnetic field illustration is given by mistake instead.

Notice that certain critical information is lacking. There is no mention of any parameters that actually govern magnetic fields such as amperage, phasing or physical specifications of the tower. Furthermore, in my experience of measuring high voltage towers, I have never seen one that could influence ambient fields (EMFs) out to 2 kilometers (over a mile) with any conventional AC gaussmeter or electric field meter.

And with regard to the safety levels, what does the term “stunted growth” mean or apply to? Is it based on studies of children or even human beings? How is the term “stunted” even quantified? Is it 1%, 10% or 34.25%? Do certain effects such as abnormal EEGs actually begin (or end) at exactly 507 meters? This figure is presented without any form of context, explanation, references or other supporting data and very little clarity. This sort of anti-information only serves to distort known physical laws into a neat and convenient visual bite that gives the reader a false sense of knowledge.

The only concept the diagram illustrates to any degree is the idea that electromagnetic fields “fall off” or diminish with increasing distance, though it does that rather badly by not explicitly stating it. But notice what is so compelling about the graphic; it is attractive, neat and gives a tabulated numbers versus certain biological effects causality that urges a viewer to adopt it as accepted fact without argument.

To re-invoke the perennial wisdom of Twain:

It ain’t so much what we know that gets us into trouble. It’s what we know that just ain’t so.

Then this sort of pseudo-scientific mythology gets incorporated into the bylaws of how EMF works (such as proliferating on the Internet) and only dilutes the cause of actual knowledge by displacing it with misdirected garbage which is worse than useless.

I have sat in on numerous high level PhD thesis defenses and if the presenter had used a slide like this, I guarantee they would be discredited on the spot for the aforementioned reasons. But without peer review or challenge, there are some who think they can become an authority on a complex subject merely by skimming some articles found online.

A phrase found in Nature (one of the most highly respected scientific journals known) in 1885, page 74 Nov 26, 1885 exemplifies this phenomena:

“A well-known lawyer, now a judge, once grouped witnesses into three classes: simple liars, damned liars, and experts.

More information can be found here:  http://scantech7.com/EMF_Survey_FAQ.htm