Thallium Poisoning

[hazelm]

I must go back and find the URL for this statement but want to paste this first:

 

"Thallium is a heavy metal used in the manufacture of electronic components, optical lenses, semiconductor materials, alloys, gamma radiation detection equipment, imitation jewelry, artist's paints, low temperature thermometers, and green fireworks.>>

 

Optical lenses?  Is it referring to eye glasses? 

 

 

The article is at https://emedicine.medscape.com/article/821465-overview

 

Thank you. 

Edited June 29, 2018 by hazelm

[exchemist]

I must go back and find the URL for this statement but want to paste this first:

 

"Thallium is a heavy metal used in the manufacture of electronic components, optical lenses, semiconductor materials, alloys, gamma radiation detection equipment, imitation jewelry, artist's paints, low temperature thermometers, and green fireworks.>>

 

Optical lenses?  Is it referring to eye glasses? 

 

 

The article is at https://emedicine.medscape.com/article/821465-overview

 

Thank you. 

I can't find out whether it is used in spectacles, but thallium (I) oxide is apparently useful in optics, due to its high refractive index combined with its hardness and insolubility (so not toxic). I am aware that in high quality optical systems achromatic doublets are used, in which two materials of different refractive index are sandwiched together in a way that corrects for chromatic aberration - the process by which any lens or prism tends to split white light into separate colours. https://en.wikipedia.org/wiki/Achromatic_lens.  This correction allows sharp images to be produced with no coloured blurs at the edges. Perhaps it is used for that purpose and related things.

 

I seem to recall learning at school that one reason for Tl's toxicity is that it has 2 oxidation states +1 and +3. In its +1 state it resembles potassium, (I think, though it must be a bit bigger), and is taken up by the body as if it were, but then it gets oxidised to +3 , which is like aluminium, and this plays merry hell with the biochemical systems into which it has been absorbed. So it's a sort of horrible chemical Trojan Horse. 

Edited June 29, 2018 by exchemist

[hazelm]

I can't find out whether it is used in spectacles, but thallium (I) oxide is apparently useful in optics, due to its high refractive index combined with its hardness and insolubility (so not toxic). I am aware that in high quality optical systems achromatic doublets are used, in which two materials of different refractive index are sandwiched together in a way that corrects for chromatic aberration - the process by which any lens or prism tends to split white light into separate colours. https://en.wikipedia.org/wiki/Achromatic_lens.  This correction allows sharp images to be produced with no coloured blurs at the edges. Perhaps it is used for that purpose and related things.

 

I seem to recall learning at school that one reason for Tl's toxicity is that it has 2 oxidation states +1 and +3. In its +1 state it resembles potassium, (I think, though it must be a bit bigger), and is taken up by the body as if it were, but then it gets oxidised to +3 , which is like aluminium, and this plays merry hell with the biochemical systems into which it has been absorbed. So it's a sort of horrible chemical Trojan Horse. 

The +3 may be how the tale got started that aluminum is poisonous.  Someone mis-read "like aluminum" as "is aluminum".  Aluminum = #13.  On-oh.  :-)   "Firefly aluminum" makes the sparkle of fireworks.  Bet you knew that.  Is that the "green fireworks"? 

 

Interesting about #1 is that another article said potassium is one cure for the poison.  I think it said the treatment has to be done fast or early.  I didn't delve into it.  Could the treatment be trying to revert it to #1?

 

So, when does it poison?  By that I mean it surely can't be from the outside in or optical goods and fake jewelry would surely not be using it.  Is it more poisonous to the persons doing the manufacturing?  Didn't they stop using nickel for rings because of such a problem? It turned the finger green.

 

We keep creating new things with new techniques and don't always know exactly what we are doing until the damage is done.  A friend and I were talking about that just the other day.  So many new medicines that should do good cause bad reactions in too many patients.

 

Trial and error on humans?  Thanks for the information.