So now I have to worry about "dirty electricity"??

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My wife asked me last night, after reading an article in a health magazine, what dirty electricity really is and why are all the CFL bulb we just put in the house effected and unhealthy. For the first time, I didnt have an informed response.

Some quick research turned up mostly filtering products and no real scientific explanation other than a handfull of studies. The following is the basic gist:

"Most of the dirty electricity is created by electrical devices in our own homes. Computers, TVs, florescent tube, CFL and low-voltage halogen lighting and virtually all of today's energy-efficient electronic devices induce high levels of high frequency harmonics and electrical "noise" back onto circuits and then into a building's electrical system creating an invisible, powerful, high frequency EMF called "dirty Electricity". This happens when transformers and power supplies convert our AC current to the low voltage power used to run all of our electronics. In the process of saving energy these energy-efficient devices chop up the conventional AC 60Hz sine wave and create what are known as electrical "transients".

So this, coupled with the risks from my radiating cell phone and WiFi equipment are now ranking up there with the concerns regarding all the ingested and inhaled carcinogens that are threaten my household.:D

Whats the deal, from an engineering perspective. :confused:

amt
 
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I have never heard that this is a health risk to humans, it is more a problem for devices that are powered off of the AC mains. It's not a new issue either, and arguments rage over the effects of EMI in everyday life.. There is very little credible evidence to support the contention that normal levels of EMI encountered in household environments constitute a real risk, that said I would not want to live near high tension transmission lines, but practically that is where I draw the line. I am not aware of any occupational risk for the linemen who work on high tension circuits beyond exposure, electrocution usually due to a moment of carelessness (but not always) and falling from high places. (Ouch)

Standard fluorescents aren't particularly good in regard to EMI either, the particular issue with CFL is most of them use electronic ballasts which generate a lot of conducted EMI on the power line and which may interfere with cordless phones, entertainment electronics, power line based signaling, and lab electronics.

Your home pc is not generally nice either unless it has a power factor (PF) corrected power supply. (Same can be said for many flat screen tv sets and computer screens if they do not use PF corrected power supplies.)

Many of the outrageously expensive A/V line conditioners you see these days were designed to deal with this issue as well as line transients due to lightening strikes (not necessarily anywhere nearby) and abrupt changes in industrial loads, etc.

To sum it up it is not something I would spend much time worrying about - the impact to you is it may degrade the performance of your entertainment electronics in some cases. Revised commercial standards for EMI and PF should reduce these issues somewhat over time as products that comply with more stringent standards become the norm.

I will admit that I do not like the light generated by CFL bulbs and will avoid them if possible anywhere I spend significant time. (I do use a few here and there, and use a lot in our Christmas decorations.) I turn off lights when not in use.

Power factor and conducted EMI are a major problem for the power utilities.
 
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iko

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For HAM enthusiasts it's a well known fact that there's a lot of transmitting devices in a regular household, sometimes where you least expect it, such as oven clocks, light dimmers, switching power supplies, etc. They usually try to fix this because it interferes with their radio stuff. As for health problems related to this, get ready for a huge debate.
 
Just don't break any CFLs as they contain mercury.

The radiation from household EMI is insignificant. You get way more from a morning in the sun.

Having seen the magnitude of high order harmonics and RF noise on the mains supply, I always put a common mode choke, power line capacitors & ferrites on my mains input (in addition to a TVS or MOV - we get lots of brownouts in the boonies)
 
The radiation from household EMI is insignificant. You get way more from a morning in the sun.

The crystal wavers are becoming nightmares for many industries. Telecom is under assault by the well meaning but tragically uninformed who can't grasp 'geometrically falling with distance' and see no paradox in using cellular and wireless to organize against transmission towers. In the Pac NW it's escalated to industrial sabotage, such as arson and towers knocked down with stolen earth moving gear.
I know tower climbers who for decades gauged their personal radiation exposure limits by joint heat. When their joints started to feel warm they came down for a while. Makes the rectification hash back-fed into the Romex behind dry wall sound inconsequential.
 
When I was going to engineering school at the University of Utah, they were doing research for some cellphone companies into the health risks of cell phone use. The brain and the eyes are very absorbent of EMF and the study of the new cell phones was turning up significant risk. So, the companies pulled the plug on the research.

I read the same article about dirty electricity, and it was centered around a problem high school. This new school had very high rate of cancer. And they found it had very high levels of electrical transients, due to poor electrical layout, and other things like widespread use of broadband networking.
 
Those two observations must be related then:rolleyes:

I'm sure the cancer rate at that school had nothing to do with prior land use or water contamination from local industry.

That's non of my concern and up to the people investigating the problem, to determine the cause. Though I'd think water contamination by industry would affect a much wider area that just the school.

It has long been argued that high voltage power lines near homes causes an increased cancer risks.
 
Yes, argued, but never demonstrated.

Correlation is not causality.

You can find a direct relationship between a person's heighth and their SAT scores. Given that 5 year olds are generally a lot less tall than 18 year olds, this should not be surprising, yet, the correlation exists.

Dirty power is not something radiated into you, it is noise on the power line that has the potential to cause noise on your audio gear, little sparkles on your video imagery, and so on.
 
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One of the most important issues... as most electronic products use full wave rectifiers... is just where do all those negative half cycles go :)

Fullwave rectifiers rectify on both half cycles so the negative half cycle goes to exactly the same place as the positive. The problem arises with half wave rectifiers... Note that many lamp dimmers (incandescent) are half wave unfortunately. Half wave rectifiers can result in measurable dc on the power line and transformers and motors don't like that much..
 
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From what I gather, DC feeding back into the AC line creates much of the noise problems but as to the radiation factor of a particular device, is it a proximity issue regarding each particular unit or is it a whole house cummulative level? It seems that the WiFi transmissions, AC lines as well as PC, CFL cell phone radiations, etc are all lumped into one large hazard.

amt
 
Yes, argued, but never demonstrated.

Correlation is not causality.

You can find a direct relationship between a person's heighth and their SAT scores. Given that 5 year olds are generally a lot less tall than 18 year olds, this should not be surprising, yet, the correlation exists.

I think most people including those investigating these problems are well aware that other factors cause cancer. I guess some people feel that we shouldn't take some simple precautions unless there is iron clad proof that there is a significant danger.

Very high frequency EMF like x-rays (ionizing radiation) can cause cancer and that is a fact.

Dirty power is not something radiated into you, it is noise on the power line that has the potential to cause noise on your audio gear, little sparkles on your video imagery, and so on.

They sure do radiate into you. So, does all the RF signals being transmitted in our world.

How much depends on the the power associated with the noise. I don't know if there is a risk with these "transient" EMF noise on power lines. Depends on the frequency and power of the noise as well as time of exposure. Would it be terrible if people started using shielded wire for power?

Energy efficient fluorescent lighting can burn your skin if in close proximity to it for an extended period of time. That's a fact. Though that's probably caused by UV light radiation.
 
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I think most people including those investigating these problems are well aware that other factors cause cancer. I guess some people feel that we shouldn't take some simple precautions unless there is iron clad proof that there is a significant danger.
I think that the issue here is that people would like at least some evidence that there actually might be a risk, before investing time and money on fixing problems that likely don't exist, especially since there are real risks that could be fixed with those resources, like traffic safety issues.

It's unfortunate that you don't remember the details of the story, because I believe it would be a good case example of the sort of nonsense that certain media outlets peddle all the time. How many cases of cancer would you need to have to have a statistical significant rate of cancer in the school to say that you have a problem? Something like 5 in one year might seem a lot, when the average is probably a lot less than 1, but it would be well within expectable numbers. Also you mentioned that the school building was new. Cancer takes years to develop, so how could they have caught cancer from EM in the new building that they just recently moved into?

There are people who are utterly convinced that low power non-ionizing EM causes all sorts of ailments and those people won't let inconvenient things like facts get in the way of their crusade; their delusions fueled by scandal-seeking media and populist politicians. Fortunately there are also people who are doing real studies on the issue, but they don't get so much media attention.
 
Corben,

I agree with you about the media and alarmists and such. Just saying that if there is a concern, that say high levels of high frequency EMFs at a school are causing health problems, it should be looked at seriously.

Here's the article, and it is qualified with a question mark in the title. We're not throwing out all our compact fluorescent bulbs yet.

Electromagnetic Fields and Your Health - Prevention.com

Here is something I found interesting in the article on page 4:

Electrical hypersensitivity (EHS) is becoming more widespread.

Symptoms of EHS, a recently identified condition, include fatigue, facial irritation (resembling rosacea), tinnitus, dizziness, and digestive disturbances, which occur after exposure to visual display units, mobile phones, WiFi equipment, and commonplace appliances. Experts say up to 3% of all people are clinically hypersensitive, as many as one-third of us to a lesser degree.

You might find this funny ... Ha, Ha, Ha? But having dealt with hyperacusis, tinnitus and global brain sensitivity for the past 12 years, I'm perfectly open to this. Who's to say the brain can't pick up and respond to these signals. Or it could also be a phobic reaction too, I don't know.

You ask an ENT about treatment for tinnitus or hyperacusis (increased sensitivity to sounds) and most will tell you it's permanent and there's not much you can do. Absolutely not true. Same for neurologists who tell their patients that neuropathy is permanent. There is a lot of ignorance (or lack of understanding) on both sides of the isle.

The truth is we don't yet know if there is a correlation between high frequency (non-ionizing) EMFs and more studies need to be done. The studies that I've seen mentioned on the internet only dealt with the low frequency EMFs commonly found in homes at the time. But, home environments are changing.

Here are some links on EMF and cancer at the national cancer institute. No proof yet that there is any connection:

Cellular Telephone Use and Cancer Risk - National Cancer Institute

Electric and Magnetic Field Exposure (EMF) and Cancer - National Cancer Institute
 
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They sure do radiate into you. So, does all the RF signals being transmitted in our world.

Exactly. The gravity of the effect, as you say, does depend on the intensity of the field, the time of exposure and the rate of exposure.

RF is RF. Microwave ovens are RF. Microwaves bake. RF bakes. RF burns. I'm not making up anything here.

As we all know, MW ovens are used to bake anything containing water in it, even at other frequencies than 2,4GHz.

RF bakes.

Need I say it again?

It probably also mutates cells and triggers diseases(too many to list) and cancer present in our bodies, but that is yet not proven.
 
Dirty electricity usually means harmonics and strange effects due to varying and possibly non linear loads.

Then there is electromagnetic radiation, which supposedly is very bad or some people think cell phones can cause brain cancer and tumors, I have heard from reliable sources (political news) that using a cell phone can increase brain temperature by one degree. I wonder how this could work - there isn't the energy to cause that effect directly, but it may trigger something else.
 
It's interesting to note that permitted radio exposure levels in the Soviet Union were a fraction of those permitted in the West. Of course these low levels were often exceeded in practise as their equipment was often crude by comparison. Still, these levels were set by their medical profession in the absence of commercial pressure. They were obviously precautionary to a degree, but at the same time, the people setting them thought they were justified for one reason or another. If we had followed them we sure as hell wouldn't have mobiles now.

I think the dangers of radio are exaggerated by the anti-phone-mast lobby, there's a known mechanism causing damage in the case of ionising radiation, but you'd have to work hard to feel that you'd got good evidence to work with now, the waters have been muddied (in some cases deliberately) by numerous interested parties.

If there is a health risk it is from permitted emissions rather than EMI tho'. EMI is, however, a serious threat to comms and nobody should lightly create circuits causing a load of EMI. I think that qualifies as 'tarnishing the Golden Rule'.

w

I once drilled a little hole in my fingernail with the RF from a 12 Watt HF radio. That had an antenna tuner tho'. 12 Watts. I treated the 200 Watt ones with a bit more respect after that.
 
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"Not-so-reliable sources. "

I think maybe some people have way to much faith in our scientific establishment to make a statement like that. Just because people are scientists does not make their public opinions scientific. If there is a danger with electromagnetic or electropotential radiation, I would bet there is a huge and very powerful interest to cover it up. Science has become political science in the universities. There is no shortage of scientists that will say that, even before climate gate, Al Gore and his melting polar bears.
 
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