Opinions on the dangers of EMF

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Karl,
You would have to understand NIH politics and the competition for research money from the different scientific groups inside.
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I think that issue exists everywhere...it seems that the conclusion of most if not all "scientific" reports matches the agenda of the group that funded the research.
Don
 
I did a paper on this back in 1992 associated with work that PG&E was involved with. One of the issues I see being missed here, although I have to admit I did not fine tooth comb all the posts, is that you have to separate electric fields from magnetic fields for this discussion. It is the magnetic fields that have caused people to be concerned.

The long and short of what I was tasked with was to determine the strength of magnetic fields from household appliances in comparison to power lines. It was found that the fields in our homes from appliances, especially microwaves and heating blankets, have much higher magnetic fields then those you will encounter from overhead power lines.

Also of note, is that unlike electric fields, magnetic fields are not easily blocked. There are special mesh materials that can be used, but simply putting power lines in the ground does no good, and actually puts the fields closer to the public.

To date, I know of no study that has conclusively been able to tie health risks/effects to magnetic fields. But, we only know what we know.

Sorta reminds me of house fires, have you ever noticed that when they can't explain how a house fire started, it's always the electrical system.
 
kingpb, what you say surprises me. Some appliances with transformers or motors (coils) have high fields which weaken very fast, with the cube of the distance. You have no exposure just a few feet away. Careful studies in CA have shown that exposure to fields from appliances is minimal compared with faulty wiring and power lines if present.

Second, undergrounding does usually reduce the fields considerably. The reason is that the conductors are close together and hence the cancellation is excellent. Surely you know this if you wrote a paper.??

Science is rational at it's core. What interferes with its progress is the pressure of 1) egos of the senior scientists who are threatened by the new theory, 2) scientific groups whose funding is threatened by a new concern, 3)industries which stand to loose revenue 4) governments whose interests (usually military) feel threatened, 5) the general media-shared concensus as to what we want to believe. (Example: this is the age of technology and communication and ipods and smart houses, etc etc. The general social attitude is go go go. Any health dangers from, say, cell phones definitely goes against the stream).

It has been hard for me to just look at the research without getting indignant when I see the spin doctors at work.

By the way, PG&E was one of the best utilities I dealt with. A number of good honest engineers there in the 80s and 90s.

Karl
 
Karl,

I've studied electrical and magnetic fields, and how they interact with all manner of things, since about the time the initial "EMF Causes Leukemia" study was published in 1979. My primary professional interest, relative to EMF, has been with how EMF wrecks havoc on such things as data and network cabling, and increasingly on how EMF affects wireless devices. (I can tell stories about people who've run RS-232 cables above flourescent lights and wondered why they were getting data errors. Go figure.) Additionally, I'm well-educated in such areas as TEMPEST (EMF related to computer security).

My undergraduate work was in Software, Mechanical and Electrical engineering. In terms of analyzing scientific studies, I've studied statistics and statistical analysis at the graduate level. Professionally, in addition to the three fields of engineering I mentioned earlier, I've worked in the Marine engineering field -- I can tell you why things float, and if they don't float, why they sink. Or break in two. Or capsize. :shock:

That's my C.V.

On a personal level (as opposed to a professional one), I've spent the majority of my life -- more than 60%, 27 out of 44 years -- on the target end of an electron gun in the form of a CRT. I tend to spend a lot of time sitting near transformers and other devices that generate strong fields. Seeing as I'd like to live to be a gray haired old lady, I have a vested interest in separating fact from fiction. I'd also like to have grandchildren and maybe even great-grandchildren some day.

First, I'm in complete agreement with you that the wiring needs to be fixed if it is generating fields. And I'll go one further -- I don't think it matters if it's a code violation or not, but discussing this on a NEC code forum, that's what some here are going to use as the guideline. Is it a code violation? Our living environment is becoming more electronic, not less, and EMF is not something that needs to be created in greater amounts.

However, when it comes to EMF and health risks, I've not seen evidence which, when taken as a whole along with all other evidence, supports a conclusion that power-line frequency EMF poses a health risk. For what it's worth, I've also not seen evidence which supports a conclusion that it doesn't. Even the California website states that the jury is still out --

Frequently Asked Questions About Magnetic Fields and Homes

When I'm told, as you've done here --

The most un-biased review of the research I know of was done by the California Health Services, a multi-year review. They identified lower levels as probable carcinogens. Curiously, I just went back to their website and put in EMF under the site search. There was nothing except a review of childhood brain tumors. A couple of years ago all aspects of the review I am speaking of was displayed. All traces have been removed.
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-- I'm going to review the literature. Again, not because of "neener, neener", but because I have a personal vested interest in knowing if sitting next to more than half a dozen little transformers, including the ones in the switching power supplies for the computers I'm sitting near, are going to kill me.

As several here have mentioned the EC&M article, I'll provide a quote from it --

The IARC panel concluded that magnetic fields were a ?possible? (IARC category 2B) human carcinogen, based on the ?limited? evidence on childhood leukemia from epidemiologic studies and the lack of supporting evidence from cell and animal studies. The evidence concerning all other cancers was insufficient to form a basis for IARC's conclusion. To put this classification in perspective, coffee, pickled vegetables, chloroform, and welding fumes are among over 200 other exposures included in IARC's ?possible? carcinogen category. IARC stated that the association between childhood leukemia and magnetic fields was not likely to be due to chance but conceded that epidemiologic artifacts could not be excluded.
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I think that the best approach remains working on problems with known risks, and relative to this forum that is working on problems with dubious electrical wiring that coincidentally generates high EMF fields.
 
Julie, good post. My only comment is that the paragraph you quote from EC&M was actually written by an EPRI spokesman. Thus one has to also consider the interest of the industry represented. The main reason I pay atention to the Cal Health Services evaluation of the research is the lack of an agenda. I am acquainted with the main scientists at CHS and admire them as human beings. The multi-year study, including the measurements in 90 schools statewide, in which I conducted the pilot study of 5 schools to nail down the field sources, was called the Cal EMFP, (electromagnetic field program.)

Many of the jobs I was called in on were in respect to EMI of sensitive electronic equipment. Tracing the fields with a gaussmeter, and then switching to a clamp-on ammerter to follow the net currents in the circuits was and is always interesting. Electricity is completely logical so the detective work always successful in the end. Do you use a gaussmeter? Without one the idea of magnetic fields is speculative and one tends to either have an image of fields all over the place, or one has to say the heck with it, I'm not going to worry. In actuality, the most electrified building should have almost zero magnetic fields through most of the space, except near devices with coils. If there is a miswired circuit (including 3-way light switching) the gaussmeter shows it like a sore thumb.

Karl
 
karl riley said:
Julie, good post. My only comment is that the paragraph you quote from EC&M was actually written by an EPRI spokesman. Thus one has to also consider the interest of the industry represented. The main reason I pay atention to the Cal Health Services evaluation of the research is the lack of an agenda. I am acquainted with the main scientists at CHS and admire them as human beings. The multi-year study, including the measurements in 90 schools statewide, in which I conducted the pilot study of 5 schools to nail down the field sources, was called the Cal EMFP, (electromagnetic field program.)
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Did anyone do a study (I've read a lot of studies -- just never seen one involving schools ...) which attempted to correlate what you found during your surveys with disease?

Many of the jobs I was called in on were in respect to EMI of sensitive electronic equipment. Tracing the fields with a gaussmeter, and then switching to a clamp-on ammerter to follow the net currents in the circuits was and is always interesting. Electricity is completely logical so the detective work always successful in the end. Do you use a gaussmeter? Without one the idea of magnetic fields is speculative and one tends to either have an image of fields all over the place, or one has to say the heck with it, I'm not going to worry. In actuality, the most electrified building should have almost zero magnetic fields through most of the space, except near devices with coils. If there is a miswired circuit (including 3-way light switching) the gaussmeter shows it like a sore thumb.

Karl
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Putting me on a plane to find out that computer cabling has no business anywhere around strong EMF would be a waste of time and money. I live in an office and try to avoid leaving it as much as possible. Except to go home.

My experience is that I have an intuitive sense of what breaks computers. Bits go in one end and come out the other. If the wrong bits come out the other end, there's only so many ways for that to happen.
 
It is the magnetic fields that have caused people to be concerned.
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That doesn?t make sense to me. How can we specify if it?s the e-field or the h-field that is the danger? Where you find one, you will likely find the other.

And if one has a biological affect then it would lay suspicion that the other might too.
Which brings gravity and acceleration under suspicion too, as a possible hazard.
 
johnny watt said:
That doesn?t make sense to me. How can we specify if it?s the e-field or the h-field that is the danger? Where you find one, you will likely find the other.

And if one has a biological affect then it would lay suspicion that the other might too.
Which brings gravity and acceleration under suspicion too, as a possible hazard.
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Research has done a very good job of ruling out electric fields already.

As for gravity and acceleration, both of those have biological affects. Plants know which way is "up", no?
 
A changing E field will _always_ be associated with a changing B field, and a changing B field will always be associated with a changing E field. This is the basis of electromagnetic radiation.

However for the purpose of the present discussion, we are looking at relatively low frequency, low intensity B fields, and the associated E fields are so low that for the purpose of discussion they get ignored.

-Jon
 
don_resqcapt19 said:
I think that it is really a sudden deceleration that is the big hazard.
Don
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That's the truth!!!! :D

Roger
 
Electric fields at power frequencies are a function of voltage; magnetic fields are a function of amperage. Electric fields are easy to shield; magnetic fields require expensive materials like mu metal or iron/aluminum sandwiches. Net current magnetic fields cannot be shielded with materials, just with counter-currents. When you correct the wiring error you re-establish the counter current.

Since one can measure electric and magnetic fields separately, researchers have had no trouble testing their effects seperately. The main place where electric fields showed up together with magnetic fields as associated with adult cancers (including lung) was in a large study of Canadian utility workers combined with workers in France. 20+ years of exposure, as I remember, showed up in the statistics most clearly. But these electric fields were associated with high voltage such as with substation workers, and would not be seen in most buildings. Researchers wanted to study this data, but as I remember Ontario Hydro owned it and refused to release it. That's the way it goes.

And Julie, the 90 school study in CA was not a health study, since they had already conceeded the concern. It was to see, originally, what the power line fields were. They were surprised (not me) that the major exposure by far was from miswiring of circuits produciung net current magnetic fields. My job was to identify and verify each error which produced the magnetic fields previously measured.

Karl
 
Karl,

What's the current state of the art with contact current research? I'd not run into that the last time I went looking at the literature, and it looks fairly promising (in a bad way) in terms of producing results.
 
There is a lot of data re: cows. Search "stray voltage". As for humans, aside from the limits built into GFIs, the only reference I know was in the EC&M article. Since that was a reprint of an EPRI article, you might search their site.

Karl
 
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