Real Life EMF Experiences?

ilander asks: "I've been looking to buy my first home recently and found one that seemed perfect. The one downside is that there are power lines directly overhead (in the yard) as well as a high tension power line tower in the empty lot in back, less than 200 feet away from the house. So does anyone have any personal experience working/living near power lines? Aside from the possible health risks, which may or not exist (depending on who you ask), will I run into any problems with my monitors and TVs? What about DSL, cable and my 802.11b network? How about digital satellite reception? Any help is appreciated!"

Comments

At the old house

[MImeKillEr]

Our first house was in close proximity to overhead powerlines. They were less than 200 ft away. More like less than 50.

The three years we lived there, we didn't notice anything strange health-wise.

I recall seeing some people do the following (not sure if this is indicative of possible health issues):

1.Take a florescent light bulb - like the overhead lights in most garages and offices. Make sure its dark out.

2. Stand under the powerline.

3. Grab the light fixture with both hands - one at either contact point (the metal ring around the outside, not the pins).

4. See if the light glows.

The theory (I guess) was that this indicated power/voltage/whatever was 'bleeding' from the powerlines. The folks who did this swore this was proof that the area wasn't safe to live in.

YMMV.

Re:At the old house

[Trelane]

Inductance. An AC (alternating current) electric line will generate a changing magnetic field (magnetic field first goes in one direction, then the other).

You have a changing magnetic field. You create a circuit (albeit one at several megaohms) when you touch the light like that. Indeed, you make a big loop.

You can find the equations for inductance in any elementary physics book. Essentially, the faster the change in magnetic field, the larger the loop the circuit forms, the larger the magnetic field change per unit time (e.g. larger oscillating magnetic field), the higher the electromotive force (voltage) induced.

Note that emv ~ dB/dt * A (B and A are vectors). That is, assuming your circuit is a 2D object (e.g. circle), then you should orient your circuit such that the magnetic field is perpendicular to it. This will give you the maximum effect.

Again, refer to college physics textbooks for more information on the subject.

Synopsis: good for scare-mongering (but remember, scare mongering's Good when you agree with the goals of the scare-mongering (e.g. nuclear power dangers) and Bad when you don't (e.g. Bush's terrorism stuff)!) but otherwise fairly pointless, unless the induced voltages and/or B/E-fields are scientifically proven to be dangerous to humans. To my knowledge, it's currently a wash. Note that statistical data for a region is questionable, since many factors enter in! (The prime exampe for correlation-does-not-prove-causation amongst my professors is the study that showed that, the more electric poles per square mile, the higher the murder rate. (Of course, the primary factor is that the denser the electric poles, the more densely populated the region)).

Resell Value

[Hungus]

BIggest issue I see is resale value. How long you plan to stay will affect things also. You may well be convinced that there are not problems with the power lines but it will be difficult to convince someone else to take it off your hands in x number of years.

I have

[slothman32]

I lived 15 years or so 200 feet from high voltage lines. And 500 from a substation. My family and my neighbors are fine. Of course I post on Slashdot so I guess that answers you question. I don't think anything happens from being near them. I didn't even care about it when I found out something might happen.

Real life induced charge

[chrisatslashdot]

I worked my way through college installing sprinkler systems for lawns and landscapes. We used a 16' metal trailer with an expanded steel deck, a steel pipe rack, and several metal lockers. On one job we parked the trailer under high voltage powerlines and got a sizeable shock if we touched the trailer with damp boots or sweaty hands.

I have also head of people filling a 55 gallon drum with coils of copper wire and stealing power from high-tension wires.

Re:Real life induced charge

[bill_mcgonigle]

I have also head of people filling a 55 gallon drum with coils of copper wire and stealing power from high-tension wires.

Very clever - I'd heard of 'clothes lines' but not drums full of coils. If they were burried with just the ends exposed they'd be pretty hard to track down.

So, what kind of electricity do you get out of such a drum? Is it clean enough to run through an inverter onto your home grid? Heh, in a reverse-metered state you could sell it back to the electric company (install a solar panel for cover).

Re:Real-Life EMF Experiences?

[dasunt]

Part of the uselessness called 'science' that they teach in schools deals with electrical current and magnetic fields.

IIRC, the strength of an electrical field is 1/(distance^2). If we have two distances, we can calculate the drop in the magnetic field as follows: (1/(d1^2)) / (1/(d2^2)) or, more simply: d1^2 / d2^2. Therefore, the difference between living directly under the power lines (assuming that the power lines are 50ft up in the air) and the difference between living a few houses away (say 200 ft) would be 2500/40000 or 5/80ths (about 6%). Living a few more houses away (say, 200 more ft) would result in a drop of 2500/160000 or about 1.5%

The point of all this math and science is that if power lines can cause cancer, it should be rather easy to detect - cancer rates would be high under the power lines, and fall off sharply.

I have never seen a study with this result, so its probably safe to assume that power lines do not cause cancer.