Slashdot Mirror
Health Consequences of CRT Monitors?
DigiMan asks: "I was wondering, what are the effects of working on a CRT are on your health - long term. It has recently bothered me that EVERYONE seems to be switching to LCD's - I noticed that Bill Gates was one of the 1st people to do this, even when the cost was super high, and many, many government offices switched to the much more expensive LCD's - despite budget cuts and having to go with the lowest bidder strategy they operate under. Was this ONLY for style and space savings? Is there some health consequence that no one talks about publically. I know that they do emit very low amounts of X-Rays and have a 60Hz magnetic field as well as a 12.5 kHz electro magnetic field (for the raster scan). I work in front of typically 3, 19" CRT's for 12 - 16 hours per day at an average distance of 18". Can these magnetic fields cause Leukemia, or anything else? Is being behind the a cathode ray tube that bad for you?"
I'm sure that CRTs affect your eyes. A local eye doctor told me once that this is because your eyes actually tend to focus about an inch behind the glass on your CRT because of the way the image is projected. Eventually this probably causes problems. Almost everyone that I knew before and after they started using computers (back in the 80s and 90s) had to get glasses within 6 months of using a computer with a CRT. Some of those people that I've talked to about this say that they most likely bought glasses because they were reading more or for longer periods of time. Unfortunately, I don't have any hard evidence to back up this claim (and many slashdotters will slam me for it) but its kinda obvious and I have a good gut feeling about it. Probably many other people feel the same way.
There is also a book by an eye doctor named William Bates (kinda a punny name for April Fools) where he talks about how to restore your normal eyesight through training. He mentions in his book that reading at close distances strains your eyes enough to distort the lens or something like that.
For reference, the rate of change of my eyesight (nearsidedness) has slowed down since I started using flat panels, but that could just be because I'm getting older. I would recommend taking breaks once or twice a day, going outside and looking out long distances.
(I hope this wasn't some kind of weird April Fools Ask Slashdot article)
Hairy palms and blindness.
Wait, that might be caused by something else...
they may cause you to loose a sense of humor and whine about stories posted on April 1st.
The Kruger Dunning explains most post on
The 60Hz refresh is bad for your eyes, LCDs are nicer to your eyes in general. I've heard there's a bit of radiation, but I don't think anywhere near what a cell phone puts out
Well dang, if I can't get a tan from my monitor, where can I anymore?
"If you were plowing a field, which would you rather use? Two strong oxen or 1024 chickens?" --Seymour Cray
Heck ya - every time a pixel switches from a 1 to a 0, the resultant decrease in entropic state causes a photon of bit radiation to be launched right at you! Fortunately, as it slowly erodes your frontal lobes, you lose the ability to care about it happening.
There is no God, and Dirac is his prophet.
"Was this ONLY for style and space savings?"
For me personally, Yes. It's all about the style and convenience. I can actually see my desk now.
For our SOC personnel that are in front of multiple large screens for an entire 8 hour shift, I think it is a nice side benefit that they are not being bathed in magnetic fields all day.
But they still look cool and take up less space. Not too mention, generate a lot less heat.
You do make an interesting point about being behind multiple tubes. I believe most measurements are made from some distance from the front of the tube.
Once again in a scenario like a call center or in our SOC this would tend to be the case when you have rows of monitors.
If all of us inside the conspiracy have been keeping the secret from you this long, why would we suddenly tell you the deep, dark truth now? Because you asked nicely?
I've had this sig for three days.
*Stares intently trying to find the April Fool's joke in this post*
Like a poster said one time: google knows all who knows all; therfore, a quick google search for Radiation King reveals
In episode 2F07, Grampa vs. Sexual Inadequacy. In it, Homer finds himself in his childhood home, and the living room wall has a shadow of Homer as a child burned into it by the Radiation King TV set. The scene then shifts to his memory of watching it in the refulgent radiation of TV the set in the process of creating that distinctive shadow on the wall.
Thus, we have answered your questions: USE LCD until such time it is determined to produces some other kind of Sexual Inadequacy Radiation.
I noticed that Bill Gates was one of the 1st people to do this, even when the cost was super high ..yeah, cause I'm sure the cost is a big concern for him huh?
air and light and time and space
any scientific tests to show CRT cause eyesight problems?
doctors say to take breaks, when doing lots of reading, be it lcd/crt/book/newspaper anyways...
Last time I went to the eye doctor (a month or two ago) he told me basically, that staring at monitors should have NO ill effects, as long as you take a break evrey once in a while. He phrased it as the 20-20-20 rule. Basically evrey 20 minutes, look at somthign 20 feet away for 20 seconds to prevent your eyes from getting strained.
First off, the human vision system was made to look at diffuse light sources; that is we're meant to look at things that are reflecting light, not emitting it. There are some strains from that. And especially from vivid colors side by side. I once saw someone with the apple color scheme - green on red. Instant migraine.
More worrisome, the x-rays being emitted out the front are carefully regulated for health reasons. However this doesn't apply to the back, which typically has 3-7 times as much radiation coming out of it. Lots of offices are setup in such a way that you are staring directly at the back of a co-workers monitor. So, your three CRT setup?
Should be perfectly safe. For you.
I am disrespectful to dirt! Can you see that I am serious?!
I started using computers at age 5. At age 9 I had one with it's own dedicated CRT (they used the TV before that). I'm now 24. So, I did need to get glasses at 22, however that was for an astygmatism in my left eye, my right eye still has perfect vision.
Now I'm a computer junky, I use them all the time, at work and at home. Until about a year ago, it was always CRTs. I now have an LCD at work, but still a CRT at home (which I am soon going to replace with another).
So in my case, an excessive amount of CRT usage doesn't seem to have caused any nearsightedness. Also not being nearsighted is counter to my genetics, my mother and father are both nearsighted, as is my sister who doesn't make much use of computers and got her glasses much younger than I did.
Again, just a personal anecdote and not a valid representation of the overall situation, but it runs completely counter to yours. I know it's compelling to think your experience is representitive, but it's very often not the case. Trust emprical research, not personal anecdotes.
LCDs use less electricity, and don't flicker.
And you see the image on the monitor how?
In places where electricity isn't cheap (such as cities)... it's cost effective to upgrade to LCD.
They have a higher up front cost, but when used 40hrs a week (and many employees leave computers on 24x7 with a screensaver)... the savings in electrical consumption make up for the cost (some say as little as a year, some say about 2 years).
When you have a larger company with 500-1000 computers, each with a display... if you can cut 1000 units down 50%... that's a considerable savings.
Some companies during the blackouts in CA pushed laptops. Not only did it encourage people to do a little work on weekends... but it cut down on power consumption in the office.
A display can last through several CPU's. The technology doesn't change that fast. Unless your a graphic artist it's irrelevent. A 7 year old 19" CRT is just as good as one bought today if it's taken care of. For most users the really subtle differences don't matter. By an LCD today, and your investing in the next several years. Get one with DVI/VGA input, and your in good shape for most users. Just swap out the CPU's every so often.
It's not just about space savings. It's cost savings.
The other thing to note is that CRT's contain a few pounds of Lead, mercury, and other hazardous materials. Several states have (or are proposing) disposal taxes for CRT's. So in the future throwing one out may cost you some cash. IT departments are well aware of this. Throwing out 1000 CRT's at $50 a pop.. that's $50,000 in additional costs.
I wrote a paper that discusses this a bit last year for an Environmental Biology course (incorporating my Business MIS studies). You can find that here. It discusses the environmental impacts of the CRT among other problems. LCD's aren't perfect, but they are much better.
1) I've been wearing rigid gas-permeable contact lenses for 22 years now (not the same set, and I take them out at night you smart-asses). I notice that when I wear these versus glasses, I can stare at most monitors for a long time without significant strain.
2) Use the best CRT monitor you can get your hands on. I've noticed that my eyestrain actually goes up working on my laptop versus my CRT (a 22" NEC MultiSync FP-series set to the highest possible resolution and very tiny fonts). It's one of those things you have to try for a few days before you realize how nice it is.
Help save the critically endangered Blue Iguana
Sorry, magnetic field are incapable of causing cancer. What causes cancer are relatively gross changes to the genetic material that lead to hyperactivity or inactivity of genes that are crucial for normal cell cycling. Some scientists believe that you actually need chromosomal rearrangements for cancer to occur (meaning malignancy, ie an invasive and metastatizing process). Indeed, most malignancies show these rearrangements. I can assure you that magnetic fields are not capable of causing this kind of damage. They cannot even cause point mutations. Obviously, ionizing radiation can, but AFAIK you don't get that from a CRT. People complaining about hypersensitivity to magnetic fields are like those suffering from multiple chemical sensitivity syndrome - they suffer from something, but the cause is entirely imaginary, fueled by magical thinking. CRT's do not make you ill. You get a headache from squinting or sitting slumped in your seat, at most.
----- One learns to itch where one can scratch.
About the 60 Hz and 10-100 KHz sweep and the dot clock and all of that -- professional fear mongers bring this stuff up all the time, but there is neither any plausible mechanism nor any experimental evidence of any danger from this stuff. In particular, for a photon to carry enough energy to damage DNA it needs to be at least in the shorter UV -- this is the mechanism by which UV, x-rays, and gamma rays cause cancer.
. I work in front of typically 3, 19" CRT's for 12 - 16 hours per day at an average distance of 18". Can these magnetic fields cause Leukemia, or anything else?
Don't worry, you'll probably die of a heart attack long before the leukemia kills you.
That's one reason government agencies switched, but there are other factors. As is well-known from such classic scientific research milestones as the G-bomb, the first private venture into space using insufficient spacecraft shielding, or poisoning by spiders exposed to ionizing radiation, the kind of hazardous rays that CRTs emit (especially from the back) have been known to induce superpowers in humans. Since the extent and strength of these powers are not predictable, the government is doing everything it can to avoid having them bestowed on listless, apathetic bureaucrats.
Bill Gates acquired superpowers years ago, of course, so he got rid of his CRT because he no longer needed the radiation. His power? He attracts money. The whole Microsoft thing is just a front to keep his power from public view so he can just exercise it over the normal course of the day. (And a good thing too. Can you imagine him in spandex?)
For true powers-seeking geeks, of course, the best course of action is to surround yourself with as many CRTs as possible. Gaming and graphic hardware companies know this, and since geeks are their main customer base both industries have been working toward their empowerment for quite some time now. This is the real reason for nVidia's TwinView technology, for example, and also the real reason why games are not developed for Linux necessitating a Windows box sitting next to the useful one. (After all, the more boxes you have in your house, the more CRTs you have pumping out those healthful X-rays.) It's no coincidence that most games involve the exercise of some kind of superhuman ability: they're trainers.
Sure, there's a serious risk of contracting some kind of cancer here, but considering the potential gains a cost/benefit analysis clearly favors bathing yourself in that wonderful blue glow.
And the brethren went away edified.
I've switched to LCDs as soon as I could get my hands on them and I've been feeling better since the move. I'm one of those very sensitive people where if I keep a cell phone longer than 5 minutes next to my ear I get a headache and my ear starts to hurt but not if I use a headphone. I happen to work in a hospital and whenever I pass through the radiology rooms I instantly get dizzy and feel like passing out in less than 5-10 of being in them. This is not a phobia, I'm not afraid of them, but my body picks up and feels the extremely strong presence of radiation even when the equipment is not in use.
I have been using CRTs very heavily in the 80's and have noticed that my vision deteriorated extensively in less than a year of serious usage (8+ hours a day) so I believe there may be a strong correlation there. Also, I'm sure that all the x-ray radiation emitted by the CRTs over your lifetime will potentially have a negative effect on your body so don't be surprised if you end up with some weird tumor or mysteriously die! I can't even think of a single positive thing (health wise) about CRTs, if you can, I definitely would love to hear about it! The real question now is, ARE LCDs safe? Given how sensitive I am I think not since I have yet to encounter any negative symptoms from heavy LCD usage.
Time to call an attorney and start a class action suite to sue those damn CRTs companies for causing my vision loss and the thousands I've spent on glasses and contacts over the years. I know I'm not the only one here!