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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)
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
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.
Long sessions in front of CRTs produce eyestrain, apparently even at high refresh rates like 85Hz from what I read. No study to back this up though.
But anyway the other problem is radiation. For the most part, the front is well shielded although some do leak out but the sides and back are not as good as the front. In some companies, as soon as someone is pregnant, their CRT is replaced with an LCD.
Of course, in the long run, LCDs save a lot more energy and that's a good thing by itself.
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?!
The joke might be that a similar topic was posted just a few weeks ago on ask/.
1 5/1537213&tid=196
http://science.slashdot.org/article.pl?sid=05/03/
The topic was slightly different, but several threads talked about benefits of lcd vs crt.
i was looking for another stupid ask slashdot again. Ah well, funs over.
"Something's wrong with you...and I hope we never do meet again." - Deftones When Girls Telephone Boys
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.
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.