Well, it was a tasteless joke. But as the preceding quote shows, anecdotally at least, people still think tv’s give off dangerous radiation.
My question(s): Do tv’s give off harmful radiation of any kind? And (2) what, if any, radiation does a tv give off?
All electronic devices produce electromagnetic radiation in the form of low-level x-rays. CRT TV’s generally give off more than LCD’s or LED’s. The most danger is to small children who sit too close to the screen; for adults the danger, if any, is negligible.
This is an old urban legend that actually has some basis in truth, though the truth of it has long been forgotten by most folks.
Back in the 1960s, several GE televisions were produced with a misaligned shield over one of the internal vacuum tubes. The end result was that the TV emitted massive amounts of X-rays. Because the X-rays were mostly emitted downward at an angle, there wasn’t any real danger for anyone sitting across the room. However, children sitting close to the television would receive very large levels of X-rays, far in excess of what was even then (in the 1960s) considered to be safe.
All of the defective TVs were recalled, but that set up the idea in the public mind that TVs produced dangerous X-rays, especially color TVs since all of the affected GE TVs had been color. Despite the recall, thousands of defective TVs were never found, but by now, it’s not very likely that any of them are still in operation.
The TV = BAD myth continued into the 70s, and even then there was still some truth to it, since CRTs do emit X-rays even during proper operation. In the mid 1970s, CRT technology advanced to the point where the levels of X-rays emitted were small enough that there was no longer any real danger from them, even for children who sat close to the set for their Saturday morning cartoons. But, if you want to be technical about it, old fashioned CRT type TVs and computer monitors do emit a small amount of X-rays. At normal viewing distances, even for a computer, the X-ray level is lost in the noise of background radiation, so it isn’t worth worrying about.
It’s just about impossible to find a CRT type TV or computer monitor these days. Flat panel TVs and monitors don’t emit any meaningful levels of X-rays or anything else harmful.
I recently helped a friend, get ready to put her house on the market, spot painting etc. On the walls behind where all the TVs were these weird dark blobs that did not rub off easily that we repainted the walls. I joked that must’ve been radiation…
high speed electrons hitting metal can produce x-rays.
electron tubes have both high speed electrons and metal so they can produce some x-rays. a cathode ray tube (CRT, picture tube) is a big electron tube with electrons being beamed towards its front viewing surface with some metal in that path.
some small amount of x-ray might be emitted from the tube. keep your genitals and eyeballs off the glass.
the Simpsons have a CRT TV (except in HD era couch gags) and an old one which constantly is breaking.
Do you know of any follow-up studies that looked at how many children had been exposed or checked those who had over the course of their lives to determine whether any problems could be attributed to the x-rays?
Well, actually CRTs do produce a lot of harmful X-ray radiation, aimed directly at the viewer.
That’s why CRTs have lead in the screen, to keep that radiation from reaching the viewer. Note the story above about what happens when the lead isn’t properly aligned.
Modern LED/LCDs emit almost nothing by comparison. I would guess less than an incadescent light bulb.
I know you were only joking, but I’m pretty sure that would just be dust attracted by static electricity on the TV set over the years.
You are probably right however all these blobs definitely had toxic look to them and no visible dust at all: just darkening and some scorched like areas with certain ominous moire patterns that looked more than just benign static dust particles (by simply rubbing the area it didn’t rub off and you got the sense as though they were more like the paint has gone through some kinda radiation like exposure and elemental change) hence my joke.
I never noticed this phenomenon before anywhere and was fascinated. I think they had older picture tube TVs before they got the newer HD TVs in the same spots.
I don’t know if any studies like that were ever done. The GE issue did end up leading to the Radiation Control Health and Safety Act of 1968.
Here is a link to a TIME article from 1967 that has details about the problem.
http://www.time.com/time/magazine/article/0,9171,837185,00.html
This paper has a lot of details about the Radiation Control Health and Safety Act of 1968 (warning - PDF):
http://leda.law.harvard.edu/leda/data/792/Tran06.pdf
GE argued that the X-rays were absorbed by other components in the TV and did not actually constitute a health hazard. There were a lot of politics involved, and I imagine that prevented a lot of unbiased research from being done, especially research that could have linked GE to a potential liability issue.
While this is true, in the GE case it was not the CRT lead that was misaligned. It was the shield on a vacuum tube used for voltage regulation.
In what world? Our local community college uses Apple G-3s with CRTs, and I think some of the poorer school districts have G-4 towers and CRTs.
We have 2 CRTs and one old TV in the house. Our older neighbors all have old style TVs, some still use antennas and required converter boxes when TV went digital.
Just because they are readily available doesn’t mean everyone has them.
I interpeted what he meant as for sale (especially as new, obviously there are SOME second hand CRTs out there) and if so he’s right. Of course many people still use CRTs, we use them for our main television viewing. We’ve been tempted to get a HD tv, but 95%+ of our programming is in SD anyway unless we want to pay a lot extra for a problematic Sky HD box. Also PAL has 576 lines which is a little better than NTSC, but either format is well capable of producing a high quality picture. Of course eventually we will get a HD tv when they go down in price and we actually get to see HD content on a regular basis with it.
For my computer I am using a 10 year old CRT monitor as well, for two reasons: 1) It has a higher resolution than any of our LCD screens at 1280x1024, so if/when I really want to watch something in HD I can use this. 2) Because CRT models have a practically negligable input lag so are much more suitable for highly intensive gaming than a LCD monitor which has input lag. CRTs also have a superior contrast display ratio… which doesn’t change depending on the angle you view it at.
And they also have multiple native resolutions and “real” zooming of pixels, which can be vastly superior sometimes since it’s much easier and cleaner to do a pixel to pixel mapping of video rather than anti-aliasing, pixel-blending, etc.