Why should we sit far from the TV?

11 October 2009

Question

When I was younger I was told not to sit too close to the TV. Is it an urban myth that it's dangerous to sit too close? Or does the TV emit radiation? Does this still apply to modern televisions?

Answer

We put this question to Andy Karam, adjunct professor at the Rochester Institute of Technology...Andy - Televisions really do give off radiation. But having said that, it's only a little bit of radiation and it's not that dangerous. What happens is that anything with a cathode ray tube, a tube where you shoot high-energy electrons at some sort of screen, when those electrons hit the screen, they give off very low energy x-ray radiation. This is the same way that x-rays are produced in regular x-ray tubes. So, if you're sitting close to a cathode ray tube, whether a computer monitor, a television screen, a radar set or anything else with that type of technology, you're going to be getting low doses of x-ray radiation.Now having said that, I've got to emphasize, they're low doses of radiation. It's not enough to be dangerous and in fact, if you watch your television for several hours a day all year, you're getting less radiation than you would from a single medical x-ray and less radiation than you get from the radioactivity that's just naturally within your body. So, it's something that we can measure, but it's not something that's harmful.LCD and plasma screens don't give off any radiation at all. They don't use high-energy electrons. It's a different type of technology. I could not say that they're safer because I don't consider the radiation from cathode ray tubes to be a risk, but I can say that they give off less radiation. As far as sitting too close to the television goes, the further back you are, the lower the radiation dose will be. But having said that, I don't consider the radiation dose even at a distance of just one metre to be dangerous.

Comments

I'm surprised that mechanical television pioneers John Logie Baird and Carl Jenkins didn't say something about CRT X-rays during their rather lopsided struggle against electronic television manufacturers in the 30's. Something like, "While dangerous high voltage x- ray producing subatomic particle accelerators may be appropriate for university physics laboratories and even well shielded doctor's offices, placing them in your family room for entertainment purposes is a highly questionable choice." While I have no statistics on X-ray injuries, I understand electrocutions and fires were not uncommon in pre-WWII television sets. By the mid 30's non-CRT mechanical television was up to 240 lines which was close to the resolution to the poorly focused 441 line TV vacuum tubes of the time. Just how clearly do you have to see Howdy Doody's face?

The radio frequency electromagnetic radiation (RF-EMR)) emitting from television when room light is off is always severe. This radiation can cause leukaemia if precaution is not taken

Can you support your claim with appropriate evidence? I doubt it.

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