Why do x-ray machines increase cancer risk?

[acesuv]

I hear they emit radiation which deionizes atoms. Is this due to the frequency of the x-ray? Is x-ray light considered radiation?

 

[Dale]

Yes. Basically the frequency of the x-ray is high enough that when an x-ray photon collides with an atom it imparts so much energy that it completely knocks off an electron. This leaves behind an ionized molecule which doesn't behave the way it is supposed to, biologically.

 

[Danger]

Actually, it's ionizing, not deionizing radiation, but that distinction is not important here.
Please keep in mind, though, that medical X-rays are not taken just for fun or profit. If you are requested by your doctor to take one, do so; it can save your life.

 

[sophiecentaur]

Actually, it's ionizing, not deionizing radiation, but that distinction is not important here.
Please keep in mind, though, that medical X-rays are not taken just for fun or profit. If you are requested by your doctor to take one, do so; it can save your life.

It was not always the case. When I was young, they had X Ray machines in shoe shops to make sure that kids' shoes fitted correctly for 'healthy feet'!
Last time I visited my Dentist he suggested that I would be better to forgo my regular X Ray check-up in the interest of my general health. How the pendulum has swung.

 

[Danger]

It was not always the case. When I was young, they had X Ray machines in shoe shops

I suspect that you're from the same era as me, though (birth certificate chiseled into a stone tablet). We never had non-medical ones on this side of the pond, but there was certainly no issue with what was available through doctors.

 

[sophiecentaur]

I suspect that you're from the same era as me, though (birth certificate chiseled into a stone tablet). We never had non-medical ones on this side of the pond, but there was certainly no issue with what was available through doctors.

That's almost unbelievable - bearing in mind how 'commercial' the US has always been. Perhaps you really are a lot younger than me (my boy). It used to annoy me because I was not tall enough to be able to look into the viewing hood and see my own feet. See this link. OR this one.

 

[Danger]

That's almost unbelievable - bearing in mind how 'commercial' the US has always been.

Them are libelous words, Sir, and I must insist that you retract them! :grumpy:
(I'm a Canuck, not a Yank, and any suggestion to the contrary is a blatant insult.)
:tongue:

Okay, so apparently you have a 20 or 30 year head start on me; I'm only 57.

 

[sophiecentaur]

Like I said - slip of a lad. I'm 67 and those machines were around in the 50s.
Sorry about dissin' your parentage.

Not long before my time, people used to take Radium Pills and all sorts of other remedies 'over the counter'. When I was born, I had a 'nevis' (strawberry mark) behind one of my ears. In fact, my Mum took me every week to a clinic and she (!) held a radium pad against the thing until it went away. Horrific.

 

[Bobbywhy]

We certainly did have "non-medical" X-ray machines here in the USA!

When I was young and went to the shoe store for new shoes, we would first try on a pair and then stand up on the big X-ray machine with both feet inserted into an opening near the bottom. When the salesman turned it on we could see all the bones of our feet and the outline of the shoe. The idea was to determine if the shoe size was correct. There were several "viewing ports", one for the child, one for the parent, and one for the salesman. Sometime in the late '50s? they were discontinued and disappeared from shoe stores. Who knows how much X-ray radiation they were sending through our little feet?

 

[russ_watters]

Is x-ray light considered radiation?

That's a bit of a mess: X-rays aren't light. Light is visible EM radiation. X-rays are EM radiation that is not at a visible frequency. But/so yes: x-rays are radiation.

 

[Danger]

my Mum took me every week to a clinic and she (!) held a radium pad against the thing until it went away. Horrific.

That might explain a few things. The closest that we got to that here was doctors recommending cigarettes for everything from stomach ache to anxiety. (I remember one hanging out of a doctor's mouth as he examined me.)

 

[sophiecentaur]

That might explain a few things. The closest that we got to that here was doctors recommending cigarettes for everything from stomach ache to anxiety. (I remember one hanging out of a doctor's mouth as he examined me.)

HAHA the treatment was very close to my brain (what there was of it).

I have looked at the press photograph on your posts. Are you sure you never had some of the same treatment?

 

[StaceyPurcher]

I suspect that you're from the same era as me, though (birth certificate chiseled into a stone tablet). We never had non-medical ones on this side of the pond, but there was certainly no issue with what was available through doctors.

Uhhh, what about things like at airports and such with x-ray machines to scan your bags as you go through...
Aren't they x-ray machines...

 

[sophiecentaur]

Uhhh, what about things like at airports and such with x-ray machines to scan your bags as you go through...
Aren't they x-ray machines...

True, but they are screened and you don't stand in them. Worry more about the staff who sit at them for hours on end. If their union allows it, the dose must be minimal, I think.
The body scanners use backscatter X Rays which use a very low dose and your body is scanned by a 'flying spot' X Ray beam. Normal tissue will just absorb it but when it encounters metal on the surface, the detectors get a scattered signal and they know which direction it came from. I Googled it and found a lot of journalistic stuff with a tiny amount of good information embedded, occasionally.

 

[StaceyPurcher]

True, but they are screened and you don't stand in them. Worry more about the staff who sit at them for hours on end. If their union allows it, the dose must be minimal, I think.
The body scanners use backscatter X Rays which use a very low dose and your body is scanned by a 'flying spot' X Ray beam. Normal tissue will just absorb it but when it encounters metal on the surface, the detectors get a scattered signal and they know which direction it came from. I Googled it and found a lot of journalistic stuff with a tiny amount of good information embedded, occasionally.

Fair enough then...
HAHAHA

 

[Danger]

I have looked at the press photograph on your posts. Are you sure you never had some of the same treatment?

Positive. That is purely the result of an unfortunate foray into home experimentation with gene splicing.

 

[sophiecentaur]

Is it possible that you were sitting next to me on the bus this afternoon? Or perhaps a co-experimenter. I moved to another seat but he followed me.

 

[technician]

It was not always the case. When I was young, they had X Ray machines in shoe shops to make sure that kids' shoes fitted correctly for 'healthy feet'!
Last time I visited my Dentist he suggested that I would be better to forgo my regular X Ray check-up in the interest of my general health. How the pendulum has swung.

Remeber it well... went to Timpsons every saturday to have my feet X-rayd...couldn't afford the shoes unfortunately, but feet were always warm on saturday...and I still have them.

 

[sophiecentaur]

Six toes on each side?

 

[ZombieFeynman]

That's a bit of a mess: X-rays aren't light. Light is visible EM radiation. X-rays are EM radiation that is not at a visible frequency. But/so yes: x-rays are radiation.

This distinction is not always true and, in my opinion, hinders understanding. It is rather common in physics to refer to electromagnetic radiation of all frequencies as light, distinguishing light we can see by prefixing it with visible. This usage is not universal, but it is widespread enough that I suggest disregarding the bolded sentence above.

 

[technician]

Six toes on each side?

When I went in the shop, but not when I came out !

 

[sophiecentaur]

This distinction is not always true and, in my opinion, hinders understanding. It is rather common in physics to refer to electromagnetic radiation of all frequencies as light, distinguishing light we can see by prefixing it with visible. This usage is not universal, but it is widespread enough that I suggest disregarding the bolded sentence above.

I don't think many people would use the term "light" to describe the way a radio wave is received. Likewise, ionising radiation is so different in important respects that it would be misleading to include it as light (except, possibly, for the bit just to the left of violet in the colours of the rainbow).

Whilst the common features of all frequencies of EM radiation are plain and should be emphasised, the distinctions are almost as relevant.

 

[ZombieFeynman]

I don't think many people would use the term "light" to describe the way a radio wave is received. Likewise, ionising radiation is so different in important respects that it would be misleading to include it as light (except, possibly, for the bit just to the left of violet in the colours of the rainbow).

Whilst the common features of all frequencies of EM radiation are plain and should be emphasised, the distinctions are almost as relevant.

You should let SLAC know. Apparently they have misnamed one of their xray lasers a Linear Coherent Light Source.

They have another one too! The Stanford Synchrotron Radiation Lightsource also emits xrays.

 

[sophiecentaur]

I must say, I find threads about 'classification' some of the least interesting in PF.
There is always a case to prove things either way and it never really helps us understand more about the subject.

 

[Danger]

I just find it easier to think of them all as light to avoid confusion. As an example:
A UV light source is racing away from me at relativistic speed, so I perceive it as being IR. Someone in between, moving at some other speed, will see "visible" light. Birds and insects consider UV to be "visible", since they can see it. Under the proper conditions, I can see the IR output of my TV remote control. How can we avoid the fact that they're all the same thing?

 

[turbo]

All upper-end clothing stores here (even in the hinterlands) in the 50's had X-ray machines to "fit" shoes to your feet. I thought it was cool to be able to see your feet in X-rays, wiggle your toes, etc. Might not have been such a good idea, but that was was the standard.

 

[sophiecentaur]

I just find it easier to think of them all as light to avoid confusion. As an example:
A UV light source is racing away from me at relativistic speed, so I perceive it as being IR. Someone in between, moving at some other speed, will see "visible" light. Birds and insects consider UV to be "visible", since they can see it. Under the proper conditions, I can see the IR output of my TV remote control. How can we avoid the fact that they're all the same thing?

I would be the last person to ignore the similarities between light, RF and gamma radiation. However, if you were thinking, at the same time, about a moving neutron and an express train, the fact they they both have mass and no net charge might not be uppermost in your thoughts. Certain other properties could be at least as relevant when considering how each one would react with me if I was standing in the way.

Also, visible light is on a cusp, where classical (wave) and QM properties are equally apparent. Once you head off, either to shorter or to longer wavelengths, their natures tend to resolve themselves more to one or the other model.

 

[Danger]

Well, consider them as sound then. A piano is somewhat comprehensive. There are lots of sounds off of either end, but you can't access them from that keyboard. They're still sound, though, even though the ultrasonics can weld plastic and the infrasonics can crumble buildings.

 

[sophiecentaur]

Well, consider them as sound then. A piano is somewhat comprehensive. There are lots of sounds off of either end, but you can't access them from that keyboard. They're still sound, though, even though the ultrasonics can weld plastic and the infrasonics can crumble buildings.

This is all down to taste really. Would you say that light waves 'were' Radio waves? If not then why is the other way round OK? It's all a matter of context. In Cosmology, the predominant view 'in our heads' is optical so it's not surprising that we use a portmanteau word like "light". It's not worth getting too aerated about imo.

 

[Danger]

It's not worth getting too aerated about imo.

Oh, man! New word of the day... :rofl:
I'll be using that one, for sure.

The fact is, I just call the whole damned works EM, but I wouldn't razz someone for calling them radio waves.

 

[sophiecentaur]

Oh, man! New word of the day... :rofl:
I'll be using that one, for sure.

The fact is, I just call the whole damned works EM, but I wouldn't razz someone for calling them radio waves.

That's what you get from going to a good English School, my boy. We learned to talk proper and learned a huge vocabulary. (I can refer to you a 'son' now I know about your extreme youth.)

 

[gmax137]

What's the evidence that those shoe-fitting X-ray machines harmed anyone?

 

[Bobbywhy]

“Years or decades may elapse between radiation exposure and a related occurrence of cancer, and no follow-up studies of customers can be performed for lack of records. Without such an epidemiological study, it is impossible to conclude whether this machine actually caused any harm to customers.”
http://en.wikipedia.org/wiki/Shoe-fitting_fluoroscope

 

[Dever]

According to medical physicists I've talked to, not only has their been better awareness of health concerns (you may remember <a href="http://gajitz.com/1950s-radioactive-science-kit-most-dangerous-toy-ever/"> this</a>), but also the technology for energy control, tight-beam collimating, signal processing, and more have made X-rays far safer than they once were. Apparently CT scans use 100 times less radiation than they did only 15 years ago.

At least that's a little comforting when your kid's standing in front of that screen. That, and that there are a couple on this page who have had their doses and still have sharp minds!

 

[Danger]

We learned to talk proper and learned a huge vocabulary.

Oh, I knew the word already; I'd just never seen it used in such a humourously ridiculous context before. I've always lived in farming country, so aeration is a daily issue. :tongue: