Is Wi-Fi safe?

superscaper

peterbaker wrote: »

Exactly! Peace and respite from the crescendo of the ether! St Peter doesn't use a Wireless Access point yet AFAIK! Just a pearly gate! And unless your idea of heaven includes streamed entertainment, you won't need anybody's wireless broadband where you're going Freddie so I totally agree with you!

No such thing as heaven (only my personal belief :beer: ) but either way I don't think any of us would be worrying about any type of radiation.

Need_More_Money_2

peterbaker wrote: »

You missed a question NMM! But thanks for also clarifying ss's average exposure in flight bit too ... he had me worried. I only ever did long haul once, but will get a big roll of foil, and butter for basting for next time!

Well you get about 2.6mSv from natural sources of ionising radiation every year (depends where you live, some places are significantly higher). So that's much more than on your flight (65 times the flight I mentioned). Better get yourself some lead underpants!:p

superscaper

Need_More_Money wrote: »

Better get yourself some lead underpants!:p

Which has the added benefit of stopping Superman seeing your privates. :T

Toothsmith

peterbaker wrote: »

Are you telling me that the enhance risk of cancer to my big toe is the same as the enhanced risk of cancer of the jawbone when I let the dentist do an X ray? I don't think so...but I stand to be corrected.

That is true Peter.

It's not so much where the beam is going, as where the scatter goes.

Most of the xray beam going through your jaw just goes straight through and passes out the other side.

Some scatters through the rest of your body.

X-rays are only really a threat to cells that are actively dividing, and although repair and renewal is going on in your jawbone and the little bit of skin & soft tissue it will all pass through, that's nothing compared to - say - the marrow of your long bones, or your testicles.

The theoretical risk from dental x-rays is such that out of all the cancers diagnosed in the UK every year, the thing that triggered off ONE of them would have been a dental x-ray. That's not cancers of the Jaw - that's ALL cancers. It is much lower than the risk from air travel, television sets, plug sockets (Yes - plug sockets are a significant source of electromagnetic radiation!) Microwave ovens and natural background radiation.

Dental x-rays are very well regulated, and machines now operate at higher kV values than ever to give as shorter exposure as possible. Films are very fast as well for the same reason, and decent dental practices will use rectangular collimation which means that the beam of xrays is only the same rectangular size as the film it's aiming at, which reduces scatter by 50%.

As I've said in the past - the best way to good dentistry is to establish a long term relationship with the same dentist, and to change dentists as few times as possible.

That way, you should maybe only need xrays every 2 years or even less depending on your individual need.

A full examination cannot be done without a radiographic examination.

By refusing to have dental xrays, you're probably not seeing the best dentists in your area, as the decent ones would probably suggest that you would be better served by another dentist. I certainly would not take responsibility for a mouth that I wasn't allowed to examine properly.

Toothsmith

BTW - a set of bite wing x-rays to check for decay between the teeth is about the same exposure as a flight to Spain and back. - 8h in an aeroplane.

Contrast that with a barium meal which is about the same as 28 years in and aeroplane.

wolfman

Very enjoyable read.

My conclusion:
Wifi is probably safer than the affects this thread will have on your brain.

Need_More_Money_2

Toothsmith wrote: »

Some scatters through the rest of your body.

X-rays are only really a threat to cells that are actively dividing, and although repair and renewal is going on in your jawbone and the little bit of skin & soft tissue it will all pass through, that's nothing compared to - say - the marrow of your long bones, or your testicles.

The nearest particulary radiosenstive area would be the lens of the eye. But the risk here is not cancer but inducing cataracts and it is a non-stochastic effect - i.e. it does not happen until above a certain very high dose (about 5000mGy, if I remember correctly. I think there may be some reversible effects at slightly lower doses). In terms of cancers, I guess the oesophagus would be the most important factor in the effective dose. But, as you say the dose is very small.

peterbaker

Need_More_Money wrote: »

The nearest particulary radiosensitive area would be the lens of the eye. But the risk here is not cancer but inducing cataracts and it is a non-stochastic effect - i.e. it does not happen until above a certain very high dose (about 5000mGy, if I remember correctly. I think there may be some reversible effects at slightly lower doses). In terms of cancers, I guess the oesophagus would be the most important factor in the effective dose. But, as you say the dose is very small.

Oh gawd NMM you and Toothsmith have me wondering again!

Damn it, I think I might have had the 28 years dose .... I am not sure when they were checking out some prostate and bowel irregularities five years ago ... I forget exactly ... except I was strung up on a Duran Duran type wheel with a tube up my butt with an audience of at least three comedians in medic garb who had me laughing so much that the tube almost popped out!

Maybe it wasn't the barium jobbie but I think it involved something radioactive?

And then there is the phenomenum of deteriorated eyesight - I have never needed to wear glasses, always being very slightly long-sighted with pretty much 20/20 vision, but although I passed an aviation Class I medical again without them two years ago, I noticed then that my focussing was deteriorated and now I can only read by lamplight with difficulty if the book is almost at arms length. So I guess at 50 its time to get reading glasses. But it has happened so suddenly, and I know it is easy to encourage others to agree such things but others around me have reported the same thing this year (seriously). My girlfriend who is a few years younger is one such. I know computer screens don't help, but .... the other exposure we share in common is about 100 Ryanair flights in the last 5 years or so.

NMM mentions cataracts of the lens. AFAIK I don't have the beginnings of that thank goodness. But my own self observation would say three things
1) The change to my eyesight is quite recent and fairly rapid onset (months not years). One eye is worse than the other (I can read with that eye but not fine focus on this 17 inch TFT screen typing at 80cm at 1280x1024). The other eye remains in focus down to about 60cm.
2) I find that I need bright daylight to do close up work or at least a bright lamp (I collect coins and used to be able to see all the detail I needed with my naked eye ... now I can either strain under a bright lamp or use a jeweller's loupe magnifier.) Last night I successfully took a watch apart and refixed a 3mm long tiny hand that had come off a Chronometer dial ... under a lamp and the loupe however ... I could not have done it otherwise.
3) I think the muscle that adjusts my lenses is effectively 'done in'. Or perhaps it only works when light intensity is high. I say this because I have a feeling my eyesight is similar to my brothers and he has no natural lens in one eye with a external contact lens instead due to an accident. He still has very acceptable eyesight but the fixed focal length lens has obvious restrictions.

Could the lens muscle also be radio-sensitive?

And finally, what is the significance of you mentioning the oesophagus NMM? Is that another equally radio-sensitive part of the anatomy? I warn my kids not to gulp over hot food and drink through danger of inadvertent repeated damage (because the oesophagus is without many pain sensing nerve endings I believe). Are you saying that cancer of the oesophagus when it occurs might commonly be a radio-induced thing? (my father-in-law died from it long before Chernobyl or mobiles or WiFi but who knows what he was exposed to during National Service!)

Edit - forgive me - the penny dropped - you mentioned oesophagus because it is nearest to the potential scattering in a dental X-Ray ...

superscaper

peterbaker wrote: »

Could the lens muscle also be radio-sensitive?

I think it's more likely down to societal habit changes. Just focussing on near objects far more hours of the day. Not only so much TV but as you say looking at a computer monitor all day in addition can't help. We're living in an information overload society where it all comes in on a near sight basis, also with mobile phones as well. If it was down to radiation we should see a lessening with the advent of LCD monitors etc which emit far less EM radiation than CRTs ever did.

At about 50 plus though long sightedness can occur very rapidly, happened to my mum years ago and I see it in my other relatives, it either happens or it doesn't and it seems to happen at about a certain age and haven't seen any difference in this pattern over recent years.

Need_More_Money_2

peterbaker wrote: »

Oh gawd NMM you and Toothsmith have me wondering again!

Damn it, I think I might have had the 28 years dose .... I am not sure when they were checking out some prostate and bowel irregularities five years ago ... I forget exactly ... except I was strung up on a Duran Duran type wheel with a tube up my butt with an audience of at least three comedians in medic garb who had me laughing so much that the tube almost popped out!

Maybe it wasn't the barium jobbie but I think it involved something radioactive?

And then there is the phenomenum of deteriorated eyesight - I have never needed to wear glasses, always being very slightly long-sighted with pretty much 20/20 vision, but although I passed an aviation Class I medical again without them two years ago, I noticed then that my focussing was deteriorated and now I can only read by lamplight with difficulty if the book is almost at arms length. So I guess at 50 its time to get reading glasses. But it has happened so suddenly, and I know it is easy to encourage others to agree such things but others around me have reported the same thing this year (seriously). My girlfriend who is a few years younger is one such. I know computer screens don't help, but .... the other exposure we share in common is about 100 Ryanair flights in the last 5 years or so.

NMM mentions cataracts of the lens. AFAIK I don't have the beginnings of that thank goodness. But my own self observation would say three things
1) The change to my eyesight is quite recent and fairly rapid onset (months not years). One eye is worse than the other (I can read with that eye but not fine focus on this 17 inch TFT screen typing at 80cm at 1280x1024). The other eye remains in focus down to about 60cm.
2) I find that I need bright daylight to do close up work or at least a bright lamp (I collect coins and used to be able to see all the detail I needed with my naked eye ... now I can either strain under a bright lamp or use a jeweller's loupe magnifier.) Last night I successfully took a watch apart and refixed a 3mm long tiny hand that had come off a Chronometer dial ... under a lamp and the loupe however ... I could not have done it otherwise.
3) I think the muscle that adjusts my lenses is effectively 'done in'. Or perhaps it only works when light intensity is high. I say this because I have a feeling my eyesight is similar to my brothers and he has no natural lens in one eye with a external contact lens instead due to an accident. He still has very acceptable eyesight but the fixed focal length lens has obvious restrictions.

Could the lens muscle also be radio-sensitive?

And finally, what is the significance of you mentioning the oesophagus NMM? Is that another equally radio-sensitive part of the anatomy? I warn my kids not to gulp over hot food and drink through danger of inadvertent repeated damage (because the oesophagus is without many pain sensing nerve endings I believe). Are you saying that cancer of the oesophagus when it occurs might commonly be a radio-induced thing? (my father-in-law died from it long before Chernobyl or mobiles or WiFi but who knows what he was exposed to during National Service!)

Edit - forgive me - the penny dropped - you mentioned oesophagus because it is nearest to the potential scattering in a dental X-Ray ...

Perhaps you could take heart from the fact that Radiologists live longer than other Doctors, despite (or perhaps because?) receiving higher radiation doses every year