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In our office, there are frequent eletric shortages that harm my desktop computer, so I wanted to install a UPS. However, my office-mates pointed me to papers talking about hazardous radiation from the UPS. The UPS manufacturers themselves recommend to put the UPS several meters away from humans, which is not possible because our office is small (the power is about 0.5 meters from us). As an alternative to UPS, my office-mates recommended that I switch to a laptop, which has a battery so it's immune to shortages. I have several questions:

  1. Is it true that the radiation from a laptop battery is lower than the radiation from a UPS? They do just the same thing - supply power using a battery!

  2. If the answer to 1 is yes - is there an alternative way to attach a battery, similar to a laptop battery, to a desktop computer?

  3. If the answer to 1 is no - how can I prove this to my office-mates, so that they let me use UPS?

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Been sitting 1m away from my UPS 10+ years and have no symptoms. –  Aki Nov 23 '12 at 13:09
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(Ask your office-mates to find one scholarly article that documents, with real measurements of some kind, the danger of a UPS. Don't accept stuff from commercial web sites that are selling fear.) –  Daniel R Hicks Nov 23 '12 at 13:15
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If "there are frequent eletric shortages that harm my desktop computer" then a UPS would seem to be mandatory, any risk would have to be a compromise. This looks like a reasonably unbiased article on the subject: emwatch.com/Computers.htm –  w3d Nov 23 '12 at 13:19
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@w3d -- I wouldn't call that article "unbiased". The levels they call "a serious health risk" would not be considered so by the vast majority of researchers. –  Daniel R Hicks Nov 23 '12 at 13:34
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@w3d: That site makes silly claims, "ELF radiation from computers: 3-6 milligauss", "The magnetic portion of this electromagnetic radiation is the most dangerous part." And yet the earths natural magnetic field is 310-580 milligauss An MRI scanner produces up to 30,000,000 milligauss –  RedGrittyBrick Nov 23 '12 at 15:50

4 Answers 4

It should be noted that the term "radiation" is often misunderstood by the layman.

Radiation consists of either electro-magnetic radiation (radio waves) or energetic atomic particles.

Energetic atomic particles only come from high-energy reactions -- a nuclear reactor, the Sun and stars, and occasionally energetic lightning strikes in the atmosphere. No common electrical equipment emits these (though some smoke detectors contain a tiny bit of "radioactive" material).

Electro-magnetic radiation (EMR) comes in a spectrum, with infrared radiation (what you feel standing near a fire) near the low end, and gamma rays on the high end. Between infrared and gamma rays are visible light, ultraviolet, and xrays.

Below infrared in the spectrum is radio waves -- AM, FM, TV, cellphones, microwaves. At the very low end of radio waves are Ultra-Low Frequency (ULF) waves. Ordinary electrical power is at 50-60 Hz (compared to 500,000 to 1,500,000 Hz for AM radio) and would be classified as ULF.

Radiation can be hazardous for basically one of two reasons:

1) "Ionizing" radiation has the ability to "knock apart" molecules in the body, potentially causing cancer or genetic mutations. "Ionizing" radiation is basically either radiation from "energetic particles" or radiation in the electro-magnetic spectrum beginning with ultraviolet (which is why sunlight can cause skin cancer).

2) Any intense EMR has the ability to damage living cells via heating (hence microwave ovens). Even though the heating may be very slight and not perceptible, damage to the delicate inner workings of the cell can occur. But while the effect of "ionizing" radiation is cumulative -- low intensity for a long time is as bad as high intensity for a short time -- this is not true for EMR. Below a certain intensity EMR simply does not cause cell damage.

(The "radiation" emitted by a UPS would be EMR, of the ULF variety -- the same radiation emitted by every other plugged-in electrical device in the building.)

There is some disagreement with regard to what the threshold should be for considering EMR dangerous, but there's been at least 50 years of research in the area and no one has come up with any real evidence that the levels we experience in a common home or office environment are anyway near the harmful threshold.

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I don't want to go into the general disagreement about non-ionizing radiation, because the majority in my office believe it is harmful. So, I am only looking for a way to compare UPS radiation to laptop radiation. –  Erel Segal Halevi Nov 24 '12 at 21:54
    
@ErelSegal -- If anything, the laptop is more hazardous, since it emits EMR at many different frequencies. Also, many common office devices will be worse than a UPS. The old electric typewriter was probably worse. A copier or laser printer emits ozone in addition to EMR. Nothing special about a UPS vs any other device. –  Daniel R Hicks Nov 24 '12 at 23:33
    
@ErelSegal -- But of course you can never prove a negative. If they're convinced that the UPS is bad, build a Faraday cage around it -- a frame (wood or whatever) with aluminum or copper screen wire, completely enclosing the device (including under it). This will reduce EMR by a factor of 100, at least. –  Daniel R Hicks Nov 24 '12 at 23:36
    
"If anything, the laptop is more hazardous, since it emits EMR at many different frequencies" - That is interesting, do you have any evidence for this? –  Erel Segal Halevi Nov 27 '12 at 10:26
    
The laptop has oscillators that generate frequencies for the display refresh, for clocking memory, for clocking the CPU, for doing I/O. These are all different frequencies, and they are higher frequencies than would be present in the UPS, and higher frequencies are (to the extent that any are) more hazardous. –  Daniel R Hicks Nov 28 '12 at 22:58

The World Health Organisation say

Electric fields around most household appliances and equipment typically do not exceed 500 V/m and magnetic fields typically do not exceed 150 mT.

...

The only practical way that ELF fields interact with living tissues is by inducing electric fields and currents in them. However, the magnitude of these induced currents from exposure to ELF fields at levels normally found in our environment, is less than the currents occurring naturally in the body.

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Is it true that the radiation from a laptop battery is lower than the radiation from a UPS?

A laptop battery should not be radiating. You can consider that lower than anything else.

They do just the same thing - supply power using a battery!

No they do not. An UPS does a lot more, e.g. it monitors voltage levels, it sends out warnings if the voltage gets too low or too high. It supplies power is the main power fails, it charges itself if it is not completely charged, ...

You can worry about that, but then you will also need to worry about the chargers for electrical phones and laptops.

If the answer to 1 is yes - is there an alternative way to attach a battery, similar to a laptop battery, to a desktop computer?

Not realistically. A desktop usew AC, a battery provides DC. You would need to convert that power and the end result is that you just build a simple UPS.

If the answer to 1 is no - how can I prove this to my office-mates, so that they let me use UPS?

Ask then to leave their much more dangerous devices at home since you are concerned about health. No more mobile phones, no more ipads, ... ( I should find a page to substantiate that, but believe me, those things radiate far more than an nicely metal shielded UPS.)

Oh, and they really should not use those things (phone, ipad) at home either. Nor a television, or a monitor.

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A laptop battery is part of an uninterruptable power supply, and although it is not usually called a UPS in that context, it is not technically different and therefore does not produce significantly less harmful radiation than the kind of UPS you were planning to install. To be more specific, both produce no hazerdous radiation whatsoever, at least to the extent where it has long lost its relevance to office workers and becomes a theoretical discussion among physicists instead.

Thoroughly proving this is not possible. Scientific consensus basically boils down to there not being any valid reason to suspect the emitted electromagnetic radiation from everyday appliances poses a health risk. Sources for this are readily and abundantly available, but so are sources for the opposite and unfortunately, their credibility isn't easily assessed by laymen. If you bring up specific arguments you are facing, they could be individually discussed in more detail, but my advice for now would be to let it slide and diplomatically convince your co-workers to buy you a laptop.

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