*Warnig* Radioactive Dust
 

I was talking with a friend of mine that repairs older televisions and tube radios; he told me about something that I'm not sure of. I asked why you find some greasy black dust in some older TV sets, what exactly was the dust. He said " Don't ever touch the dust inside a TV set, It's radioactive, Very Dangerous". I do not know if he was trying to joke around with me, or if he was serious. He went on to say " a TV set is the most dangerous item in someone's home, that is why the coat the back of the backs with lead". Is he feeding a line of Bull poop? :D

I've never heard of radioactive dust in TV's...the only radiation is a low level of x-rays produced by High voltage rectifier and regulator tubes. The metal shielding around these tubes is enough to contain the x-rays, so that an ordinary user is protected from them. There were apparently some h.v. rectifier tubes which actually had a lead coating on them for x-ray shielding, although I have never seen them.

I believe most HV rectifier and regulator tubes, also picture tubes, have leaded glass to control x-rays. The only time I have heard of toxic dust is in some types of microwave tubes such as magnetrons, which may contain beryllium? which is said to be very toxic.

Modern TV's have no HV rectifier tubes, and have x-ray protection circuits to shut down the HV if it goes high enough to produce x-rays in the picture tube.

You do have to be careful with the picture tubes because of mercury in the tube (the same goes for light bubls and fluorescent lights). The other thing you need to worry about PBB - polybrominated biphenyls. They are used as insulating material but can cause dust etc. TOXIC!!!

Dave

I have often wondered why some places in the set gets greasy. I can understand the dust getting in there, but grease? Maybe it was another WD-40 user? :eek:

The grease could be PBB's. Please be careful with that stuff - causes all types of nasty diseases - cancer, etc. We wouldn't want to loose any of the AK family.

Most electronics have PBB's in them untile the mid 80's.

Dave

My fifth grade homeroom teacher was a sort of consipiracy theorist/health nut, etc. He said that if you held your arm up to the screen of the tv and changed the channel your hairs would stand on end, and that it was caused by a shot of radiation sent out by the tube. Said that the radiation would go in your arm and stay there, it couldn't get out. Pure b.s., of course, but I really think he believed it. Kinda like with irradiated food, people think it will cause problems, but a radioactive ray can't make something radioactive.

I don't think I'd add that sticky grease from inside a tv to my diet. It wouldn't surprise me if it had PCBs in it. Some of the ooze I've seen from bad can caps can be scary looking, although from what I've read the ones in consumer electronics should be okay.

Not they have been using PBB's - that was a major report - www.eia.org/resources/1998-01-01.11.pdf
and http://www.productstewardship.net/PD...icsEdesign.pdf and http://www.nemi.org/roadmapping/ECE_...is_Meeting.pdf


These list all the things that are hardardous in consumer electronics.

Dave

The only things I know of that are actually radioactive are the meter faces in the R-3XX series of recievers. There was a big frou-frou awhile back about it, but then it was realised that no deaths from radiation have ever been attributed to an R-390A, since the amount was so small & you would have to press yr face up against said meter for something like 45 years to get a larger-sized zit. Seems like there was a radiation scare from color TVs back in the early 1960s, but that was solved ages ago. Don't eat the dust in the back of an old radio or TV & youshould have practically nothing to worry ABOUT.-SANDY g.

I was told years ago that the sticky stuff that holds the dust is actualy nicotine. That is why you see it in some sets and not others. Depends on wheather the owners smoked. Has anyone else heard this?

I have a set here that came from a heavy smoker's house, and you can definately see the coating on everything.

The greasy substance that I see occasionally may not necessarily be on the entire chassis. Many times I find it on and around certain tubes (and many times it's in the HV cage).

bgadow said: My fifth grade homeroom teacher was a sort of consipiracy theorist/health nut, etc.

I worked with a guy that was the same way. This was my favorite: he claimed that back in the 70's, the Canadian government could watch you in your home through your television if you had cable! Of course, you had to be in front of the tv for them to see you. This guy firmly believed in this! What a freakin nut!!! :screwy: :screwy:

This is too much.
 

Tv's have dust in them because the HIGH VOLTAGE attracts the dust. And what is this about Mercury in CRT's? True, the phospor in Crt's in somewhat dangerous, but I NEVER heard of mercury in them. Fluroescent lamps do have Mercury, as do Sodium, Mercury vapor,Xenon, and other gas-vapor lamps.

BTW, the MICROWAVE OVEN is the most dangerous item in most peoples homes. the power supply in them produces over 3000 v., at current levels approaching ELECTRIC CHAIR levels!!

Jack,

I would assume that everyone here already knows that the dust in the set is attracted by the HV. I could be wrong, but my understanding is that we were trying to figure out where the greasy residue come from that we ocssionally find in the set.

As far as all of the other "wild" sounding theories being discussed here (picture tube putting radiation in the arm, radioactive dust, and the government watchin us), well, those were told to us by someone else that obviously should have kept their mouths shut. It didn't mean we believed them.

Don't lose faith in us my friend! :wave:

Guys- That ain't nothin'. I'll guarantee I could find a few "little old lady" types who won't talk on the phone on the weekend 'cos that's when The Phone Co."Blows the Lines Out." -Sandy G.

i haven't heard that one before, but that's freakin hilarious! :lmao: :nutz: :headscrat :scratch2: :screwy:

CRT paranoia and other urban legends
 

All this is quite interesting from a cultural standpoint. The whole "TV is bad" concept gets a boost from bad science and other half truths (like all radiation is evil). Remember how your mom said watching TV is bad for your eyes?

An old coworker just told me that he read somewhere that the dust on computers is toxic waste. I'm afraid he actually believed this CRAP. I've seen a local laser printer repair joint claim the static charge on CRTs and laser printers causes headaches, eyestrain and the heartbreak of psoriasis (OK I just made up the last one).

As for the junk that accumulates insides TVs, its just the airsnot that's floating around in the stuff we breathe. I used to work on arcade games and the circuit boards would get caked with whatever was airborne. Nicotine, pizza grease, animal hair, etc. The stuff just precipitates out of the air but more so on HV circuits.