# Radiation danger from sitting at a computer screen 11 hours a day? **URL:** \ **Category:** Factual Questions\ **Created:** [October 4, 2004, 7:18pm UTC](https://boards.straightdope.com/t/radiation-danger-from-sitting-at-a-computer-screen-11-hours-a-day/267505 "2004-10-04T19:18:44Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![chappachula](https://avatars.discourse-cdn.com/v4/letter/c/d2c977/32.png) [@chappachula](https://boards.straightdope.com/u/chappachula)\ **Post date:** [October 4, 2004, 7:18pm UTC](https://boards.straightdope.com/t/radiation-danger-from-sitting-at-a-computer-screen-11-hours-a-day/267505/1 "2004-10-04T19:18:44Z")
A computer technician (who I respect–his tech knowledge has solved lots of hardware problems for me) just told me that he bought himself a flat screen because of the radiation danger, and recommended that I do the same. Is he right? Or at least reasonably close to being correct? A generation or two ago (back when color TV was new), mothers used to yell at their kids not to sit too close to the TV because it was “Bad for you”.Was the radiation beamed at you from a cathode ray tube back then more powerful and dangerous than today? And is a computer screen today similar? I sit at a computer 9 hours a day at work, and at home for another half hour (if the SDMB is dull that day) or 1-2 hours (if there are any threads about terrorism, Mid-east politics, or kittens). Am I slowly frying my body? Cell phone radiation has been declared to be either: 1) a mortal danger to all users or 2) no danger at all to anybody , depending on who you ask. So is computer radiation a similar issue? ---
**Author:** ![spingears](https://avatars.discourse-cdn.com/v4/letter/s/ebca7d/32.png) [@spingears](https://boards.straightdope.com/u/spingears)\ **Post date:** [October 4, 2004, 8:22pm UTC](https://boards.straightdope.com/t/radiation-danger-from-sitting-at-a-computer-screen-11-hours-a-day/267505/2 "2004-10-04T20:22:15Z")
> [@chappachula](#): > > A computer technician (who I respect–his tech knowledge has solved lots of hardware problems for me) just told me that he bought himself a flat screen because of the radiation danger, and recommended that I do the same. Is he right? Or at least reasonably close to being correct? A generation or two ago (back when color TV was new), mothers used to yell at their kids not to sit too close to the TV because it was “Bad for you”.Was the radiation beamed at you from a cathode ray tube back then more powerful and dangerous than today? And is a computer screen today similar? I sit at a computer 9 hours a day at work, and at home for another half hour (if the SDMB is dull that day) or 1-2 hours (if there are any threads about terrorism, Mid-east politics, or kittens). Am I slowly frying my body? Cell phone radiation has been declared to be either: 1) a mortal danger to all users or 2) no danger at all to anybody , depending on who you ask. So is computer radiation a similar issue? TV screen of all colors, flat or not are cathode ray tubes,CRT’s. Get your Tin Hat and wear it every time you sit down in front of any one of them. Plasma and LED displays may result in eyestrain the same as CRT’s. ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [October 4, 2004, 9:46pm UTC](https://boards.straightdope.com/t/radiation-danger-from-sitting-at-a-computer-screen-11-hours-a-day/267505/3 "2004-10-04T21:46:17Z")
> [@chappachula](#): > > A generation or two ago (back when color TV was new), mothers used to yell at their kids not to sit too close to the TV because it was “Bad for you”.Was the radiation beamed at you from a cathode ray tube back then more powerful and dangerous than today? Yes. From here (which seems to be down, but here’s the [Google cache](http://64.233.167.104/search?q=cache:TMvLxaQygUoJ:http://www.noradcorp.com/3tutor.htm)): > [@](#): > > The warnings we heard as children were reactions to the widely publicized fact that color television sets were emitting harmful levels of X-radiation, or X-rays. X-rays and other ionizing radiations are so named for their ability to ionize an atom or molecule by altering its structure, literally stripping off atomic particles and changing the structure of the atom, thereby making it unstable. … > > Congressional hearings were held and, in 1968, the Radiation Health and Safety Act was passed. It established standards for these emissions which were phased in until full compliance was required by all CRTs in 1971. (CRTs, or Cathode Ray Tubes, are the display tubes found in televisions, computer monitors and displays.) I don’t know what the current state of research is, but I’ll note that cell phones (a) are designed to emit radiation, and (b) are (maybe not literally, but almost) 100 times closer to your body than your average CRT. Since radiation falls off as the square of the distance, it seems likely that you’ll get a **lot** more radiation from your cell phone than from your monitor. Oh, and I’m sure there’ll be some wag along shortly to point out that you couldn’t **see** your monitor if it didn’t emit radiation, because light is a form of radiation. Mark my words. ---
**Author:** ![ticker](https://avatars.discourse-cdn.com/v4/letter/t/d07c76/32.png) [@ticker](https://boards.straightdope.com/u/ticker)\ **Post date:** [October 4, 2004, 10:07pm UTC](https://boards.straightdope.com/t/radiation-danger-from-sitting-at-a-computer-screen-11-hours-a-day/267505/4 "2004-10-04T22:07:12Z")
This was a big deal ~15 years ago - pregnant women were being advised not to use VDU’s (as monitors were still being called in those days). Even though tests showed the risks were grossly exagerated (i.e. practically non-existant), modern monitors are built to conform to far stricter radiation standards. ---
**Author:** ![Cleophus](https://avatars.discourse-cdn.com/v4/letter/c/a88e57/32.png) [@Cleophus](https://boards.straightdope.com/u/Cleophus)\ **Post date:** [October 5, 2004, 2:09am UTC](https://boards.straightdope.com/t/radiation-danger-from-sitting-at-a-computer-screen-11-hours-a-day/267505/5 "2004-10-05T02:09:40Z")
> [@spingears](#): > > TV screen of all colors, flat or not are cathode ray tubes,CRT’s. Get your Tin Hat and wear it every time you sit down in front of any one of them. Plasma and LED displays may result in eyestrain the same as CRT’s. What? Are you seriously stating a flat-panel TV contains a cathode ray tube? **chappachula** , a cell phone emits radio waves, which are a type of **non** ionizing radiation. Although X-rays and radio waves (along with visible light) are all part of the electromagnetic spectrum, radio waves do not have enough energy to ionize atoms. Direct comparisons on the effect of radio wave exposure and X-ray exposure are misleading at best. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [October 5, 2004, 2:31am UTC](https://boards.straightdope.com/t/radiation-danger-from-sitting-at-a-computer-screen-11-hours-a-day/267505/6 "2004-10-05T02:31:45Z")
First of all, let’s settle the issue of what we are talking about here. There are lots of types of electromagnetic radiation. As you go up in frequency, the electromagnetic spectrum looks something like this: | radio waves | infra-red | visible light | ultraviolet | x-rays | gamma rays | At the lower end of the spectrum, the waves are non-ionizing (meaning that the waves aren’t capable of stripping electrons off of atoms and creating ions). Once you start getting into the ultraviolet section though, the waves start to become ionizing. Ionizing radiation is well known to cause cell damage and cancer. It’s the higher frequency stuff like X-rays and gamma rays that folks talk about when they talk about the dangers of “radiation.” Cell phones emit radio waves. At a high enough level, radio waves can cause quite a bit of damage. After all, this is how a microwave cooks your food. At lower levels though, the radio waves from a cell phone are no more harmful than shining a flashlight onto your skin. Higher levels can cook you, but then so can high levels of visible light too. The problem with computer monitors is that in addition to the visible light radiation that they emit (which is their whole purpose in life) they also emit the higher frequency ionizing radiation, which is known to be dangerous. Many years ago I had access to a geiger counter and on a whim I stuck it up against a computer monitor. The thing went bezerk. However, at a reasonable distance away from the monitor (like where you would be) the geiger counter wasn’t chirping much above background radiation. I don’t have access to a geiger counter these days, but I’m told the higher frequency radiation levels are significantly lower than they used to be. I don’t think there’s much to worry about. Still, if you’d rather be safe than sorry, flat panel monitors don’t work the same way, and since they don’t have a CRT they don’t emit the dangerous types of radiation. ---
**Author:** ![bouv](https://avatars.discourse-cdn.com/v4/letter/b/bc8723/32.png) [@bouv](https://boards.straightdope.com/u/bouv)\ **Post date:** [October 5, 2004, 4:19am UTC](https://boards.straightdope.com/t/radiation-danger-from-sitting-at-a-computer-screen-11-hours-a-day/267505/7 "2004-10-05T04:19:19Z")
> [@Cleophus](#): > > What? Are you seriously stating a flat-panel TV contains a cathode ray tube? Well, I’m not **spingears** , but he may have been referring to flas _screen_, not flat _panel_. A flat screen can be a CRT, or it can be a flat panel (LCD or plasma.)