jvz@sdcsvax.UCSD.EDU (John Van Zandt) (07/01/87)
I recently heard of a screen cover for shielding the user from radiation generated by the video monitors. Does anyone know the name of companies which build/sell these items? As usual, email to me and I'll summarize the results. Thanks, John Van Zandt uucp: ucbvax!sdcsvax!jvz arpa: jvz@UCSD
wtm@neoucom.UUCP (Bill Mayhew) (07/04/87)
About a year ago we tested several different types of terminals and CRT screens for personal computers in our building for emission of ionizing radiation. I don't have quantitative figures at hand, but all screens gave off very little radiation. The safety officer concluded there ought to be little health risk unless you routinely sit within an inch or two of the screen, which isn't likely. Chances are pretty good that the so-called radiation filter screens would not significatly reduce the amount of radiation reaching the user. Remeber that they do very little to reduce the emission from the sides and bottom of the case. There is a very, very tiny amount of merit in the protective CRT screens in that they may tend to reduce, slightly, the static electricity build-up. This ought to slightly reduce the likelyhood of computer crashes due to static discharge. We've found that the most objectionable aspect of CRT screens is that some emit very intense ultrasonic acoustical energy. While I'm not a physician, I'd imagine that this has a greater physiolgical impact on computer users than RF energcy coming from CRTs. Some CRT terminals emit a very high pitched whine (probably ~15 KHz) that I can hear; I've found it very uncomfortable to work at those terminals for more than a short time. My suggestion would be to look into getting a computer that is equipped with an LCD or plasma display type screen, if you are concerned with RF emissions from CRTs. The voltages present in LCDs and plasma screens is quite low: ~200 volts or less. That should prevent any sighnificant high energy radiation from being generated. Note, however, that some plasma screens do emit a discernible audio whine at ~2 KHz. While not dangerous, such a whine might prove distracting if the computer is used in a very quiet area. The newer "turbo" models of the Zenith Z-181 can make quite acceptible desktop units, if you feel avoiding radiation is that important. The above does not reflect any policy or medical opinions of my employer or the State of Ohio. Opinions expressed are strictly personal. Bill Mayhew Division of Basic Medical Sciences Northeastern Ohio Universities' College of Medicine Rootstown, OH 44272-9989 USA phone: 216-325-23511
john@uw-nsr.UUCP (John Sambrook) (07/05/87)
In article <3392@sdcsvax.UCSD.EDU> jvz@sdcsvax.UCSD.EDU (John Van Zandt) writes: >I recently heard of a screen cover for shielding the user from >radiation generated by the video monitors. Does anyone know the >name of companies which build/sell these items? As usual, >email to me and I'll summarize the results. > The last time I had my eyes checked the doctor mentioned that it is possible to purchase eyeglasses that have been treated to reduce UV transmission. Whether this is important or not I can't say. Even if you don't need corrective lenses you can obtain eyeglasses that have "plain" glass lenses that have been treated to reduce UV transmission. -- John Sambrook Dial: (206) 545-7433 University of Washington WD-12 Inet: john@nsr.acs.washington.edu Seattle, Washington 98195 UUCP: uw-nsr!john
doris@csd4.milw.wisc.edu (Doris Brust) (07/07/87)
I was going to buy a screen/filter to use while working on the computer but since I work at 4 different sites in the city, I did not want to have to carry this screen all over the place. Also, the screen I wanted was made by Polaroid. It reduced glare, UV rays, etc. and was VERY nice but for $150.00 I should hope so. Afterwards, I went to my father's optometrist and spoke to him about glasses to reduce glare, UV rays, etc. He asked me what color screen I work on and what kind of lighting was in the rooms where I work. My answers were a green screen and flourescent lighting. Even though I don't wear glasses, Dr. Myers said to come in, pick out frames, and then he'll make the lenses - nonprescription, UV treated and whatever else must be done to make them equivalent to the $140.00 screen. Well, I now have a pair of glasses with very light voilet tinted and UV treated lenses. I really like them and the $80.00 price tag sure beats the $140.00! They're also easier to carry around in my purse than a screen/filter. *************************************** Doris Brust University of Wisconsin - Milwaukee Computing Services Division UUCP: uwmcsd1!uwmcsd4!doris ARPA: doris@csd4.milw.wisc.edu Excellence lies not in doing one thing well but in doing everything surperbly. ***************************************
henry@utzoo.UUCP (Henry Spencer) (07/08/87)
> Chances are pretty good that the so-called radiation filter > screens would not significatly reduce the amount of radiation > reaching the user... Note also that they almost certainly *will* make the screens harder to see... and problems with eyestrain and posture are known to be endemic in CRT applications. -- Mars must wait -- we have un- Henry Spencer @ U of Toronto Zoology finished business on the Moon. {allegra,ihnp4,decvax,pyramid}!utzoo!henry
wyle@ethz.UUCP (Mitchell Wyle) (07/11/87)
In article <8273@utzoo.UUCP> henry@utzoo.UUCP (Henry Spencer) writes: >> Chances are pretty good that the so-called radiation filter >> screens would not significatly reduce the amount of radiation >> reaching the user... > >Note also that they almost certainly *will* make the screens harder to >see... and problems with eyestrain and posture are known to be endemic >in CRT applications. Please refer to my letter in March "87 Byte, the VOLUMES of data published in "The Health Physics Journal," and the Government studies on radiation and CRTs. There is NO radiation danger from CRTs! If you live or work in a well-insulated stone building, your CRT will attract Radon gas, which may nuke you when you breath it. The data are not all in yet regarding the radiological dangers of Radon. -- Mitchell F. Wyle | csnet or arpa: wyle%ifi.ethz.ch@relay.cs.net Instituet fuer Informatik | uucp: wyle@ethz.uucp ETH Zentrum / SOT | Telephone: 011 41 1 256 5237 8092 Zuerich, Switzerland