Fluorescents and migraines??

http://tinyurl.com/296h8p
Is there any truth to this article?
I read another article claiming some of the old American house
wiring won't handle CFLs. How can that be if CFLs take less amperage than incandescents?
Dean
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That's more a medical question than an electrical one, but adjustments to how CFL's are manufactured could solve that problem.

That's just silly.
CS
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CS wrote:

Crossposted to sci.engr.lighting Does the spectrum cause migranies and "skin eruptions"? I thought migraines were flicker rate which should be a non-issue with CFLs.

I agree
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I think these might have started from a couple of BBC articles last week accompanying short news features on radio/TV.
http://news.bbc.co.uk/1/hi/health/7167860.stm is an article with an alarmist headline and nothing credible to back it up, and an explanation near the bottom of how the misunderstanding has come about. Basically an alarmist piece of crappy jornalism.
http://news.bbc.co.uk/1/hi/health/7167860.stm is the other article. It's been discussed on the radio and the people affected are affected by any bright light including sunlight.
These are remarkably poor articles, particularly for the BBC, which are being picked up and propapated by other parts of the media. It's been accompanied radio/TV coverage giving time to those who just want to moan about filament lamps being phased out.
There are actually real issues presented by the phasing out of filament lamps, but those aren't getting any coverage at all, of course.
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Andrew Gabriel wrote:

CFLs run at high frequency giving high frequency (probably totally invisible) flicker. Is the high frequency flicker modulated at 50Hz giving a visible flicker? (Just curious.)

(This is the same link.) CFLs shouldn't be brighter than incandescents???
So you can get migraines from "low intensity of the light" (1st article) and other problems from the bright light. And both problems are caused by CFLs.
Does the spectrum of fluorescents cause skin problems as the original link claimed?

It is comforting to know that bad news reporting is not unique to the US.

Thanks for the further information.
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No. There could be 100Hz modulation. There is with some filament lamps, but no one claims they give migranes.
You get 50Hz flicker from tubes on old magnetic control gear if they are partially rectifying the discharge. This can happen with badly manufactured tubes where one of the electrodes isn't working well, and tubes in the last couple of hours of life when the last bit of emissive material is just wearing off one end immediately prior to the tube going out. 50Hz flicker is certainly uncomfortable to many people, resulting in stress and headaches, and I suspect is a trigger for migraines in some people.
I think it's this effect which has got mixed up with the issue of compact fluorescents, although it's impossible with electronically ballasted fluorescents used in compact fluorescent retrofit lamps.

Oops, should have been http://news.bbc.co.uk/1/hi/health/7170246.stm
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Andrew Gabriel wrote:

I should have said 100Hz but comments about 50Hz are interesting. My guess is the DC drops substantially twice a cycle which should produce modulation. But the phosphor persistence would counteract that depending on the value of persistence. I hadn't thought about filament lamps...
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bud-- wrote: [snip]

If any, certainly not more severe than old style tubular fluorescents. There was a discussion in s.e.l. long time ago, where it was mentioned that the glass used on old style tubular fluorescents allows wavelengths down to 370-380nm.
Mercury at low pressure emits a triplet at 365nm, but it is strongly absorbed by the various phosphors used in fluorescent lamps, to the point where its existence can barely be detected on high precision spectroscopes.
There is no question for wavelengths below 365nm, because the soda lime glass used on fluorescents strongly absorbs such radiation.
I've measured many CFLs with my spectroscopes, and I cannot detect any appreciable radiation below 390-400nm.
There are lamps which emit radiation all the way down to 365nm, most notably high pressure mercury and metal halides. I've never heard any claims that these give rashes or skin problems. If the claim for CFLs was true, it certainly would be true for these lamps as well.
For example, black light mercury vapor lamps used in discos which emit most of their radiation at 365nm, would be the first obvious culprits for skin problems, but again, I've never heard such claims.
On the other hand if there are people who are skin-sensitive to the region between 370-400nm, then one could possibly make a case, but as with all things, this would be an exception.
Lighting is not designed with such rare population samples in mind.
[snip]

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The 365 nm triplet is actually a weak feature of the low pressure mercury vapor discharge. It is related to the 577-579 nm yellow triplet, which is also a strong feature of a high pressure mercery vapor discharge but a weak feature of the low pressure one.
Most fluorescent lamp phosphors do not utilize 365 nm, though the usual mid-blue component of triphosphors 3500K and higher does utilize it.
Also, soda lime glass is nearly enough transparent at least down to 340 nm. However, not much 310 nm gets through, and I think that is the next shorter wavelength significant spectral feature of mercury vapor (another triplet in the same series as the 577-579 and 365-366 nm ones).
Try exposing various fluorescents to a BLB blacklight. My experience is that triphosphor ones 3500K and higher glow bright blue, meaning the glass passes the UV. Most other fluorescents give little or no reaction, indicating that the phosphor does not utilize that wavelength.
- Don Klipstein ( snipped-for-privacy@misty.com)
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Don Klipstein wrote: [snip]

My Optics reference (K.D. Alexopoulos, General Physics, Optics, Athens, 1966), seems to agree with Don's 340nm for regular glass.
However, as much as I would hate to disagree with Don and with the above reference, in my experience the above is a tad low. I have in front of me the OSRAM catalog which gives the peak for UVA sun-tanning indium-amalgam fluorescents, L40W/79 K In, as 350nm.
If the 340nm lower bound for regular glass was correct, suntanning would be possible behind regular glass windows. But it's not. Hence the 340nm figure for soda lime glass cannot be correct.
[snip]

Note however that the direction of radiation with respect to the glass envelope and phosphor may be crucial to the transmissivity of UV. Whereas *outcoming* 365nm radiation may pass through the glass envelope and hit the phosphor and excite it, this *DOES NOT* mean that there is *incoming* 365nm radiation which manages to survive both the phosphor AND the CFL glass envelope and radiate outwards.
As I said, spectroscopic analysis does not show any appreciable amounts of radiation below 390nm, except traces in regular 2700K CFLs.
I will gladly stand corrected if anybody shows a specific spectrogram from a calibrated spectroscope with non-trace amounts of UV below 390nm.
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That sounds long to me for suntanning. Wavelengths longer than about 330-335 nm or so don't do that much.

I thik the effective cutoff wavelength is a little longer for windows and a little shorter for fluorescent lamps, in part from window glass being thicker, and in part from window glass having a slight tinting by iron.
As for fluorescents made specifically for suntanning - I think they would use a different glass to pass even shorter wavelengths.

I don't expect there to be a whole lot because the 365-366 nm triplet is a weak feature of the low pressure mercury vapor discharge.
Some spectral power distribution curves:
http://ledmuseum.home.att.net/spectra7.htm
Look for "Trisonic" 6500K (halophosphor) ones, all others noted as "dollar store" ones, and compact fluorescents noted as 2700 K, Sylvania "white" (halophosphor). The 365-366 nm feature is about half as strong as the 404.7 nm one in all of these.
Two non-phosphor lamps that emit UVC are shown also: A "Water Purifier" one and a "UVC" one (though with weak UVC output). The latter also has 365-366 about half as strong as 404.7, and the former has more 365 (I have seen a similar lamp get hotter and have higher mercury vapor pressure - that may be the explanation).
I tried getting the spectral power distribution of a Sylvania F40/350BL. (Copying and pasting links is messy with Sylvania's website - I would try searching their USA "business" lamp catalog for F40350BLECO 30/CS 1/SKU or 24922.)
The spectral power distribution has the 365-366 nm spike smaller than the 404.7 nm one, and there is a little one shown at 310 nm.
- Don Klipstein ( snipped-for-privacy@misty.com)
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Don Klipstein wrote: [snip]

I am not sure why you are bringing the above lamp kinds into the discussion.
These are UVA/UVB/UVC CFLs/fluoros, and they are not used for commercial lighting, so they are irrelevant to the question asked.
For the /third time/, and to return to one of the thread subjects: UV content in regular lighting CFLs is insignificant, so any claims of skin rashes coming from UV in CFLs are bogus, unless the test subject is skin-sensitive to the 390-440nm area.
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For a paper published some years ago on the UV output of "white" light linear fluorescent lamps, we found that there was a substantial UV differential between T8 lamps made in Europe and North American produced T8 lamps. An analysis indicated that the amount of iron in the glass was the primary reason. Higher iron content reduces UV output.
Terry McGowan
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I agree that the UV output below 390 nm of most general lighting fluorescents is low. I was adding data to support my claim as to why it is usually low - the low pressure mercury arc does not produce much between the 253.7 and 404.7 nm features, and that mid-UVA (specifically 365-366 nm) passes through most glass and many to most fluorescent lamp phosphors (so the glass is usually not the explanation for relative lack of mid-UVA and often the phosphor is not).
- Don Klipstein ( snipped-for-privacy@misty.com)
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| CFLs run at high frequency giving high frequency (probably totally | invisible) flicker. Is the high frequency flicker modulated at 50Hz | giving a visible flicker? (Just curious.)
If they convert to DC and smooth it first, the answer would be no. Since I see flicker from many CFLs, then it must be that not all of them do it. FYI, this flicker is not what bothers me.
| Does the spectrum of fluorescents cause skin problems as the original | link claimed?
What about unfiltered halogens?
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On 9 Jan 2008 05:57:59 GMT, snipped-for-privacy@ipal.net wrote:

They do smooth the DC - but not enough to remove all the 100/120 Hz flicker.
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| http://news.bbc.co.uk/1/hi/health/7167860.stm is the other | article. It's been discussed on the radio and the people | affected are affected by any bright light including sunlight.
I know I am affected by very bright light due to the brightness. But if restricted enough, and that light is fine for me as a task or reading light. Fluorescent lights, including CLFs, even when at low brightness, can give me a headache within about 20-30 minutes
| There are actually real issues presented by the phasing out | of filament lamps, but those aren't getting any coverage at | all, of course.
Like how many CFLs does it take to keep my ophidian friends warm?
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On 07 Jan 2008 19:25:00 GMT, snipped-for-privacy@cucumber.demon.co.uk (Andrew Gabriel) wrote:

Perhaps not so crappy, since integral CFLs can have flicker even if they use high frequency electronic ballasts. See my other note.

This is the same link as the first.0

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| Does the spectrum cause migranies and "skin eruptions"? I thought | migraines were flicker rate which should be a non-issue with CFLs.
I see CFLs that flicker. Probably very cheap ones. But they exist.
BTW, I bought an LED flashlight the other day that has a white spectrum that does not bother me like other LEDs and all fluorescents and metal halides do. And it's a rather bright and well built one. LEDs are now looking more like they could be my future efficient lighting method.
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On 9 Jan 2008 05:52:14 GMT, snipped-for-privacy@ipal.net wrote:

Line-powered LEDs can also flicker if the DC link is not properly filtered.
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