gcw20877@uxa.cso.uiuc.edu (George Wang) (04/10/90)
I am just curious whether GAS PLASMA SCREENS (such as the one found in Toshiba laptops) emit some form of radiation like those found in CRT screens... How do Gas Plasma screens work exactly? If they don't emit radiation are they safer from a health viewpoint? Please reply via email and I will post a summary if needed.. Thanks George -- George Wang University of Illinois gcw20877@uxa.cso.uiuc.edu
jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) (04/11/90)
In article <1990Apr10.002440.9812@ux1.cso.uiuc.edu> gcw20877@uxa.cso.uiuc.edu (George Wang) writes: >I am just curious whether GAS PLASMA SCREENS (such as the one found >in Toshiba laptops) emit some form of radiation like those found >in CRT screens... CRT's DO NOT emit any radiation other than visible light! Anyone that says otherwise is a vendor trying to use scare tactics to get you to buy his screen filter product. Probably the thing that some people mistakenly think is radiation is the static electric charge on the surface of the screen that you can feel when you bring your arm near to the screen. >How do Gas Plasma screens work exactly? If they don't emit radiation >are they safer from a health viewpoint? Gas plasma screens work like miniature neon lights. The gas ionizes and gives off light. -- John Dudeck "You want to read the code closely..." jdudeck@Polyslo.CalPoly.Edu -- C. Staley, in OS course, teaching ESL: 62013975 Tel: 805-545-9549 Tanenbaum's MINIX operating system.
kdq@demott.COM (Kevin D. Quitt) (04/12/90)
In article <26226d66.1467@petunia.CalPoly.EDU> jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) writes: > >In article <1990Apr10.002440.9812@ux1.cso.uiuc.edu> gcw20877@uxa.cso.uiuc.edu (George Wang) writes: >>I am just curious whether GAS PLASMA SCREENS (such as the one found >>in Toshiba laptops) emit some form of radiation like those found >>in CRT screens... > >CRT's DO NOT emit any radiation other than visible light! You're making a joke, right? Besides the RF they produce at both horizontal and vertical scanning frequencies (plus harmonics, plus hetrodynes), and besides the electrons that get through the phosphor, color CRTs give off xrays, mostly in the direction of the user. Commercial Xray machines have a beam of electrons slam into a metal target to generate the radiation. In a color CRT, one or more beams of electrons slam into the shadow mask to prevent any but the center group to pass to the phosphor - the results are the same. The only question is how much radiation comes out, and that varies depending upon the type of glass used on the face of the tube, but mostly on the voltage applied between the cathode and anode on the tube itself. kdq -- _ Kevin D. Quitt Manager, Software Development DeMott Electronics Co. VOICE (818) 988-4975 14707 Keswick St. FAX (818) 997-1190 Van Nuys, CA 91405-1266 MODEM (818) 997-4496 Telebit PEP last 34 12 N 118 27 W srhqla!demott!kdq kdq@demott.com "Next time, Jack, write a God-damned memo!" - Jack Ryan - Hunt for Red October
dts@pwllheli.sw.stratus.com (Daniel Senie) (04/12/90)
In article <26226d66.1467@petunia.CalPoly.EDU>, jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) writes: |>CRT's DO NOT emit any radiation other than visible light! Explain this: Take the handset off of a standard telephone (Bell 2500 saeries, for example) and unplug it from the phone. Hold the handset near your CRT and put your ear to the receiver. Where do you suppose the buzzing noise you hear is coming from? CRTs most certainly emit radiation other than visible light. Daniel Senie UUCP: uunet!lectroid!dts Stratus Computer, Inc. ARPA: dts@lectroid.sw.stratus.com 55 Fairbanks Blvd. CSRV: 74176,1347 Marlboro, MA 01752 TEL.: 508 - 460 - 2686
feg@moss.ATT.COM (Forrest Gehrke,2C-119,7239,ATTBL) (04/12/90)
In article <140@demott.COM>, kdq@demott.COM (Kevin D. Quitt) writes: > In article <26226d66.1467@petunia.CalPoly.EDU> jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) writes: > > > >CRT's DO NOT emit any radiation other than visible light! > > You're making a joke, right? Besides the RF they produce at both > horizontal and vertical scanning frequencies (plus harmonics, plus > hetrodynes), and besides the electrons that get through the phosphor, > color CRTs give off xrays, mostly in the direction of the user. > Before spouting off for the whole world, please determine some facts. If you pasted a piece of X-ray photographic film on the face of a color crt for a month, you MIGHT, just might, find a faint amount of evidence of X-ray emission. Faces of crt are fairly thick and are made of lead glass. Any x-ray emission through lead glass had better be damned energetic. X-ray emission from the much higher voltage TV color CRT's is still soft x-rays and is mostly emitted from the edges of the CRT where the glass envelope is much thinner. All manufacturers are aware of this and are required to provide shielding in the outer edge areas. Still, this is soft xrays and you would have to have your face up against the glass for hours to get any amount of penetration from this radiation. If you can find any electrons penetrating the glass face you are a better magician than Houdini ever was. As to RF at the low frequencies involved (just above the audible range--15khz for most, up to 35 khz for some of the VGA's) and the low power, if you can find time to worry about that, you should definitely avoid driving past standard broadcast antenna farms. The main concern with PC's is the RFI they produce for desired radio reception, not the other way around. This is why the FCC requires certification from PC manufacturers. Forrest Gehrke feg@dodger.ATT.COM
feg@moss.ATT.COM (Forrest Gehrke,2C-119,7239,ATTBL) (04/12/90)
In article <1074@lectroid.sw.stratus.com>, dts@pwllheli.sw.stratus.com (Daniel Senie) writes: > In article <26226d66.1467@petunia.CalPoly.EDU>, > jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) writes: > > |>CRT's DO NOT emit any radiation other than visible light! > > Explain this: Take the handset off of a standard telephone (Bell 2500 > saeries, for example) and unplug it from the phone. Hold the handset > near your CRT and put your ear to the receiver. Where do you suppose the > buzzing noise you hear is coming from? > Before we get too far down this path, let's be certain everyone knows the difference between electromagnetic radiation (radio, for instance), and ionizing radiation (xrays, for instance). What you are hearing in your telephone is the detection of the scanning circuits electromagnetic radiation. If you place a radio receiver near your PC you will hear all sorts of radio radiation produced by the various circuits in the PC. None of this is produced by the CRT. This radio emission is the same you will hear if you place a receiver near a TV set. The latter is producing a good deal more than a PC, BTW. Forrest Gehrke feg@dodger.ATT.COM
kaleb@mars.jpl.nasa.gov (Kaleb Keithley) (04/12/90)
In article <26226d66.1467@petunia.CalPoly.EDU>, >jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) writes: >CRT's DO NOT emit any radiation other than visible light! Bzzzzzzt! Wrong! If CRTs don't emit any radiation, then please explain: 1. Why pregnant women who work in front of CRTs have a statistically higher chance of miscarriage than pregnant women who don't work in front of CRTs. 2. Why the Scandinavian countries *require* CRTs with additional shielding to reduce the emission of electro-magnetic radiation. 3. Not really germain to the subject, but why do families who live near high tension (voltage) power lines have a statistically higher rate of cancer, miscarriage, learning disabilities, and other maladies. In fact so much higher, that in many countries, housing may not be built anywhere near such power lines. This sounds like the age old dillusion; If you can't see it, it must not exist. Probably tens of thousands of people in the not too distant past suffered from horrible maladies, because they could not see things like X-rays or gamma rays. X-rays were used as party gimmicks around the turn of the century, everyone at a party would stand for an X-ray picture, during which the room would be flooded with high energy X-rays. Factory workers at Curie's factory outside of Pittsburgh, PA. routinely took home used bricks and other building materials which had been exposed to radioactivity; to use in their own homes, exposing themselves and their families to long term, low level, radiation doses. I know, this isn't really the appropriate arena for this topic, but we must fight ignorance wherever it exists. If you must, flame me by email so that the rest of the world won't be subjected to it. kaleb@mars.jpl.nasa.gov Jet Propeller Labs Kaleb Keithley spelling and grammar flames > /dev/null
truesdel@sun418.nas.nasa.gov (David A. Truesdell) (04/13/90)
feg@moss.ATT.COM (Forrest Gehrke,2C-119,7239,ATTBL) writes: >In article <1074@lectroid.sw.stratus.com>, dts@pwllheli.sw.stratus.com (Daniel Senie) writes: >> In article <26226d66.1467@petunia.CalPoly.EDU>, >> jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) writes: >> |>CRT's DO NOT emit any radiation other than visible light! >> Explain this: Take the handset off of a standard telephone (Bell 2500 >> saeries, for example) and unplug it from the phone. Hold the handset >> near your CRT and put your ear to the receiver. Where do you suppose the >> buzzing noise you hear is coming from? >Before we get too far down this path, let's be certain everyone >knows the difference between electromagnetic radiation (radio, >for instance), and ionizing radiation (xrays, for instance). Yes, lets make sure that everyone DOES know the difference between between radio waves, and x-rays. Except for the energy level of the photons... THERE IS NO DIFFERENCE. Radio waves and X-rays are just differnt forms of the same thing. If you don't understand this I'd suggest that you refresh your knowledge of basic science, and quickly. >What you are hearing in your telephone is the detection of the >scanning circuits electromagnetic radiation. If you place a >radio receiver near your PC you will hear all sorts of radio >radiation produced by the various circuits in the PC. None >of this is produced by the CRT. This radio emission is the >same you will hear if you place a receiver near a TV set. What do the "scanning ciruits" of a CRT emit? Electromagnetic radiation. What does a PC emit? Electomagnetic radiation. What does a TV emit? Electomagnetic radiation. What does a Xray machine emit? Electomagnetic radiation. It's all the same thing, just different at different frequencys. Oh, and a radio receiver is not the best tool for the job of measuring EM emissions. It's designed to only look at a small portion of the broadcast band, which is why it can pick out individual stations. I expect what you are picking up from the CRT's and TV sets is the fairly strong, low frequency (10's to 100's of kHz), emissions from the scanning circuits being picked up by the amplifier, while the tuner is probably picking up the higher frequency harmonics from the switching of the digital circuits inside the PC. -- T.T.F.N., dave truesdell (truesdel@prandtl.nas.nasa.gov)
truesdel@sun418.nas.nasa.gov (David A. Truesdell) (04/13/90)
kaleb@mars.jpl.nasa.gov (Kaleb Keithley) writes: >In article <26226d66.1467@petunia.CalPoly.EDU>, >>jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) writes: >>CRT's DO NOT emit any radiation other than visible light! >Bzzzzzzt! Wrong! If CRTs don't emit any radiation, then please explain: >1. Why pregnant women who work in front of CRTs have a statistically higher > chance of miscarriage than pregnant women who don't work in front of > CRTs. From what I remember, the study you're referring to didn't take into account the socio-economic status of the women. A possible alternate explanation could be that the women who use CRT's the most (Word-processing, data entry) had lower incomes, and thus could not afford the same level of prenatal care, then the women who would use CRT's the least (managers). Note that I'm not saying that the effect isn't real, just that it hasn't been proven to be linked to CRT's. >2. Why the Scandinavian countries *require* CRTs with additional shielding > to reduce the emission of electro-magnetic radiation. It would be interesting to know what study's prompted this. >3. Not really germain to the subject, but why do families who live near > high tension (voltage) power lines have a statistically higher rate of > cancer, miscarriage, learning disabilities, and other maladies. In fact > so much higher, that in many countries, housing may not be built anywhere > near such power lines. Really? What countrys have such restrictions. From what I've read on the subject the difference in the disease rates hasn't been shown to be very large at all. >This sounds like the age old dillusion; If you can't see it, it must not exist. >Probably tens of thousands of people in the not too distant past suffered from >horrible maladies, because they could not see things like X-rays or gamma rays. >X-rays were used as party gimmicks around the turn of the century, everyone >at a party would stand for an X-ray picture, during which the room would be >flooded with high energy X-rays. Factory workers at Curie's factory outside >of Pittsburgh, PA. routinely took home used bricks and other building >materials which had been exposed to radioactivity; to use in their own homes, >exposing themselves and their families to long term, low level, radiation >doses. Be careful, as it sounds like you might be suffering from one of those delusions yourself. First, a large number of those people died, not because the radiation was invisible, but because many quacks were selling Xray treatments as magic cures for any ailment. Others sold "radium water" as medicine. People today still visit an old uranium mine, because they believe that breathing radon gas will help treat arthritis. The problem with Curie and the workers was that they didn't know the dangers of excessive exposure, and that they took no precautions against inhaling the radioactive dust, or against carrying it home on their clothing. Second, "long term, low level" radiation probably isn't as harmful as many technophobe activists make it out to be. If it were, you would expect that those who live in areas with higher levels of backgound radiation to have a higher incidence of cancer and related diseases, and this turns out not to be the case. -- T.T.F.N., dave truesdell (truesdel@prandtl.nas.nasa.gov)
chuck@eng.umd.edu (Chuck Harris) (04/13/90)
In article <5096@cbnewsl.ATT.COM> feg@moss.ATT.COM writes: >In article <1074@lectroid.sw.stratus.com>, dts@pwllheli.sw.stratus.com (Daniel Senie) writes: >> In article <26226d66.1467@petunia.CalPoly.EDU>, >> jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) writes: >> >> |>CRT's DO NOT emit any radiation other than visible light! - A number of years ago I got curious about COLOR CRT's and ionizing - radiation. So to find out a bit about it I just put a Geiger Counter - to the face of the color TV's CRT, and guess what??? - The CRT was increasing the background radiation by about 2 times! - - Well, your mention of CRT radiation reminded me of that experiment, so - since I spend a lot of time in front of a COLOR CRT, I thought I'd measure - the x-rays again, and guess what??? NOTHING, Nada, none! - - How can this be? Did I remember wrong? No, my memory is ok, it is just - that the first time I measured a color CRT was about 15 years ago. In the - 15 years since then, color CRT's have changed from being a "window to the - world" that sat 6-7 feet away from the viewers to the common CRT on your - desk 18" away from your face. - - The old color TV of 15 years ago used about 30Kv anode potential. Your - new color terminal/PC uses about 20Kv and has LEAD in the glass to block - any of the soft X-Rays that are produced. >> >> Explain this: Take the handset off of a standard telephone (Bell 2500 >> saeries, for example) and unplug it from the phone. Hold the handset >> near your CRT and put your ear to the receiver. Where do you suppose the >> buzzing noise you hear is coming from? >> > - This effect is the one that worries me more than any X-Rays coming from - your PC's monitor. There are a lot of people theorizing that Extremely - Low Frequencies (ELF) radiated from Cathode Ray TERMINALS (CRT is ambigous), - and the power lines, might be causing Cancer, Leukemia, miscarraiges and - birth defects. - - As they say: "all the facts aren't in yet" I am anxiously awaiting the - facts. Chuck Harris C.F. Harris - Consulting
dhinds@portia.Stanford.EDU (David Hinds) (04/13/90)
In article <3366@jato.Jpl.Nasa.Gov>, kaleb@mars.jpl.nasa.gov (Kaleb Keithley) writes: > In article <26226d66.1467@petunia.CalPoly.EDU>, > >jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) writes: > > >CRT's DO NOT emit any radiation other than visible light! > > Bzzzzzzt! Wrong! If CRTs don't emit any radiation, then please explain: > > 1. Why pregnant women who work in front of CRTs have a statistically higher > chance of miscarriage than pregnant women who don't work in front of > CRTs. A statistical correlation does not imply cause and effect relationships. CRT's DO emit very low levels of soft X-rays, in addition to low amounts of non-ionizing electromagnetic radiation. The effect of long-term exposure to this sort of radiation has been notoriously difficult to pin down. It is extremely difficult to make sound statistical judgements about human populations when the signal to noise is already expected to be weak - how do you control for the effects of sitting in a particular position for extended amounts of time? Perhaps eye strain, or stress in general, is the relevant causal factor in this case. Maybe people who work for long periods in front of CRT's tend to be more irritable than others. Or maybe they tend to drink too much coffee to combat their sore eyes. If it were shown that when women work with better-shielded CRT's their risk of miscarriage declines to baseline, then this would be convincing. > 2. Why the Scandinavian countries *require* CRTs with additional shielding > to reduce the emission of electro-magnetic radiation. Government regulatory policy is seldom a reliable guide in risk assessment. > 3. Not really germain to the subject, but why do families who live near > high tension (voltage) power lines have a statistically higher rate of > cancer, miscarriage, learning disabilities, and other maladies. In fact > so much higher, that in many countries, housing may not be built anywhere > near such power lines. I don't know if this is true or false, but I thought the issue had not been resolved. The levels of low-frequency radiation emitted by an unshielded 115000 volt power line are considerably higher than those from a CRT, however. > This sounds like the age old delusion; If you can't see it, it must not exist. As opposed to the growing delusion that if you can't see it, or spell it, or know your grandfather lived to a ripe old age eating it, it must be bad for you. Neither is much of a substitute for careful analysis of risks. You might say, err on the side of caution, but if these "invisible enemies" come to dominate popular conceptions of risk, many ordinary yet far more serious risks may be neglected. -David Hinds dhinds@popserver.stanford.edu
kdq@demott.COM (Kevin D. Quitt) (04/13/90)
In article <5096@cbnewsl.ATT.COM> feg@moss.ATT.COM (Forrest Gehrke,2C-119,7239,ATTBL) writes: >In article <1074@lectroid.sw.stratus.com>, dts@pwllheli.sw.stratus.com (Daniel Senie) writes: >>In article <26226d66.1467@petunia.CalPoly.EDU>, >>jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) writes: >> >>|>CRT's DO NOT emit any radiation other than visible light! >> >>Explain this: Take the handset off of a standard telephone (Bell 2500 >>saeries, for example) and unplug it from the phone. Hold the handset >>near your CRT and put your ear to the receiver. Where do you suppose the >>buzzing noise you hear is coming from? >> > >Before we get too far down this path, let's be certain everyone >knows the difference between electromagnetic radiation (radio, >for instance), and ionizing radiation (xrays, for instance). Forest, you gotta read the whole thing. The first guy said *ANY* radiation - that's what we both jumped on. Nobody said how much. kdq
wallwey@boulder.Colorado.EDU (WALLWEY DEAN WILLIAM) (04/13/90)
For those of you who are interested in the health risks assosiated with CTRs and computers, Check out the article a couple of months ago on it in PC Magazine. I think its the one announcing the new HP-EISA 486, but not sure--Don't have the magazine here. PC Mag. did quite a few tests, and it seems like me, unless you keep your face within about 10 inches of the screen, you don't have too much to worry about. Personally I would worry more about your water-bed heater or electric blanket than your computer / electric power lines! (This last sentence is purely a personal opinion-not by any means a proven fact!!!) Even if the radiation is twice background, that is still alomost nill. I live here in Boulder Colo. and due to the high altitude and lots of radon (relatively) coming out of the ground, I probably endure a couple of times higher radiation rate just due to where I live 24Hrs a day than most people get from their computers(esp. since most people don't live within 24 inches of their computers 24Hrs. a day). Note this last paragraph is pure speculation!!!!(Don't flame-broil me if I'm wrong!) Hope that helps, Dean Wallwey
cramer@optilink.UUCP (Clayton Cramer) (04/14/90)
In article <3366@jato.Jpl.Nasa.Gov>, kaleb@mars.jpl.nasa.gov (Kaleb Keithley) writes: > In article <26226d66.1467@petunia.CalPoly.EDU>, > >jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) writes: > > >CRT's DO NOT emit any radiation other than visible light! > > Bzzzzzzt! Wrong! If CRTs don't emit any radiation, then please explain: > > 1. Why pregnant women who work in front of CRTs have a statistically higher > chance of miscarriage than pregnant women who don't work in front of > CRTs. Other possibilities include: 1. Prolonged sitting position putting strain on the abdomen and back, with deleterious effects on the baby. (I can tell you working in front a CRTs gives male engineers very high rates of back and neck pain -- but not because of radiation). 2. Other shared characteristics of the work force? In my experience, women working as data entry operators are FAR more likely to smoke than women who work in other office jobs. This may be a quirk of the places I've worked -- but I wouldn't discount the possibility that there are explanations. A few years ago, someone found that cancer rates in one of the Bay Area counties were extremely high. The obvious conclusion was that air pollution from the oil refinery was at fault. A more careful study found that the oil refinery hired large numbers of blue collar workers, relative to the surrounding counties, and blue collar workers are much likely to smoke. THIS was the cause of the cancers -- not air pollution from the refinery. > 2. Why the Scandinavian countries *require* CRTs with additional shielding > to reduce the emission of electro-magnetic radiation. Very effective lobbying efforts are all that this demonstrates. > 3. Not really germain to the subject, but why do families who live near > high tension (voltage) power lines have a statistically higher rate of > cancer, miscarriage, learning disabilities, and other maladies. In fact > so much higher, that in many countries, housing may not be built anywhere > near such power lines. I've read enough about this to believe there may be a problem associated with high tension power lines, but those aren't CRTs. > kaleb@mars.jpl.nasa.gov Jet Propeller Labs -- Clayton E. Cramer {pyramid,pixar,tekbspa}!optilink!cramer Politicians prefer unarmed peasants. Ask the Lithuanians. ---------------------------------------------------------------------------- Disclaimer? You must be kidding! No company would hold opinions like mine!
cramer@optilink.UUCP (Clayton Cramer) (04/14/90)
In article <5601@amelia.nas.nasa.gov>, truesdel@sun418.nas.nasa.gov (David A. Truesdell) writes: > feg@moss.ATT.COM (Forrest Gehrke,2C-119,7239,ATTBL) writes: > > >In article <1074@lectroid.sw.stratus.com>, dts@pwllheli.sw.stratus.com (Daniel Senie) writes: > >> In article <26226d66.1467@petunia.CalPoly.EDU>, > >> jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) writes: # ## |#CRT's DO NOT emit any radiation other than visible light! # ## Explain this: Take the handset off of a standard telephone (Bell 2500 # ## saeries, for example) and unplug it from the phone. Hold the handset # ## near your CRT and put your ear to the receiver. Where do you suppose the # ## buzzing noise you hear is coming from? # # #Before we get too far down this path, let's be certain everyone # #knows the difference between electromagnetic radiation (radio, # #for instance), and ionizing radiation (xrays, for instance). # # Yes, lets make sure that everyone DOES know the difference between # between radio waves, and x-rays. Except for the energy level of the # photons... # # THERE IS NO DIFFERENCE. # # Radio waves and X-rays are just differnt forms of the same thing. # # If you don't understand this I'd suggest that you refresh your knowledge of # basic science, and quickly. Hey! Stop directing those headlights at me! You're going to give me cancer! :-) The difference in energy is substantial, and makes the difference between a wave that you can spend all day looking at (visible light), and a wave that will crisp your insides (microwaves), and a wave that will rearrange your DNA (gamma rays). This carelessness about distinguishing ionizing radiation from non-ionizing radiation is going to lead us back into the Green Dark Ages. # dave truesdell (truesdel@prandtl.nas.nasa.gov) -- Clayton E. Cramer {pyramid,pixar,tekbspa}!optilink!cramer Politicians prefer unarmed peasants. Ask the Lithuanians. ---------------------------------------------------------------------------- Disclaimer? You must be kidding! No company would hold opinions like mine!
dmurdoch@watstat.waterloo.edu (Duncan Murdoch) (04/14/90)
Most of the discussion of radiation from CRTs so far has been about xray and RF electromagnetic radiation. But most CRTs are also strong ultrasound emitters. Personally, I find it very irritating to be in the same room as some colour TVs or CGA monitors for long: they're both emitting strongly at 15 KHz or so, just within the range I can hear, and very nerve racking. I remember once having my IBM EGA monitor tested, and in CGA modes the 15 KHz emission was easily detectable, but in the EGA modes, where I thought things were fine, it was even louder at 20+ KHz. I wonder how many health effects from CRTs are actually due to the sound, not the EM radiation? Duncan Murdoch
jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) (04/14/90)
I see that my remark to the effect that CRT's don't emit any radiation except visible light caused quite a reaction, due, I suppose, to the fact that I didn't take care to mention all the facts, which were subsequently enumerated by many netters. A few of you understood my statement in the sense that I intended, which was to raise a protest against the notion that CRT's posed a health hazard due to the ionizing radiation that they emit. The article to which I was responding was asking whether gas plasma screens are any less of a health hazard in regards to their emission of radiation. I knew perfectly well that crt's emit radio frequency and audio frequency electromagnetic radiation, and I know that the larger CRT's may even emit an X-ray here or there. But the point is that they are so infinitesimally weak that they can be ignored. It seems to be one of the characteristics of our modern society that there is a lot of concern about the infinitesimally small risks, while ignoring the major ones. But that is a topic for a different newsgroup. -- John Dudeck "You want to read the code closely..." jdudeck@Polyslo.CalPoly.Edu -- C. Staley, in OS course, teaching ESL: 62013975 Tel: 805-545-9549 Tanenbaum's MINIX operating system.
kdq@demott.COM (Kevin D. Quitt) (04/14/90)
It was never my intention to indicate that the radiation that comes
from CRTs is, in fact, harmful. (It may be, but that has yet to be
properly determined). My purpose was to correct an obviously false
statement.
Boy, one word ("harmful") would have saved a lot of band-width!
(8-{)} (See? We're all happy again)
kdq
--
_
Kevin D. Quitt Manager, Software Development
DeMott Electronics Co. VOICE (818) 988-4975
14707 Keswick St. FAX (818) 997-1190
Van Nuys, CA 91405-1266 MODEM (818) 997-4496 Telebit PEP last
34 12 N 118 27 W srhqla!demott!kdq kdq@demott.com
"Next time, Jack, write a God-damned memo!" - Jack Ryan - Hunt for Red October