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Bondee
580080.  Tue Jul 07, 2009 7:56 am Reply with quote

...not the music. That's "heavy metal", singular.

Efros wrote:
I keep wanting to post stuff about Cadmium poisoning on this thread.


Your wish is my command! Post away, sir!
: )

 
Efros
580374.  Tue Jul 07, 2009 1:32 pm Reply with quote

Cadmium (Cd) element 48 is classed as a so called heavy metal. It is in the same group of transition metals as Zn and Hg. Cd is actually named after Zn, the latin Cadmia actually translates as calamine, which is zinc carbonate. Cadmium has many industrial uses, most frequently when used in alloys it is there to improve the mechanical/electrical properties of the alloy.

Cadmium poisoning results from environmental exposure or through ingestion. Cigarette smokers inhale significant amounts of Cd whenever they smoke tobacco. I used to work with a machine that could detect when a cigarette smoker had entered the room. The machine was based on an atmospheric sampling apparatus that was primarily for the detection of Beryllium but could be tuned for Cd. Other sources include old industrial areas that have been disturbed, e.g. there was significant concern about the building of the motorway section on the south side of the Clyde in Glasgow. Cd is used extensively in the manufacture of plastics and various coatings, the manufacturing process and the eventual disposal are the times when Cd is most likely to be ingested.

Cd poisoning can lead to flu like symptoms which if the exposure is a one-shot can go away with little lasting damage. Anosmia is another common symptom. Severe poisoning will result in lung damage if exposure is from inhalation, pulmonary oedema, kidney problems if not failure, bones can lose calcium and become weak. Kidney function impairment in irreversible and can lead to conditions such as gout where uric acid is not removed effectively from the bloodstream.

Like many other industrial "diseases" Cd poisoning has had its most famous outing in Japan, where it is known as itai-itai.

 
Posital
580535.  Tue Jul 07, 2009 4:00 pm Reply with quote

A selenium drum used to sit in the heart of a photocopier.

 
Efros
580592.  Tue Jul 07, 2009 5:11 pm Reply with quote

Se is poisonous if taken in excess, although it is an essential trace element and as a cofactor for the reduction of certain enzymes which act as antioxidants. It is however a non-metal and isn't classed as heavy.

 
Posital
580609.  Tue Jul 07, 2009 5:58 pm Reply with quote

You should try shifting one of those silvery drums.

But yes.

 
Janet H
581555.  Thu Jul 09, 2009 2:35 pm Reply with quote

Uranium pretty damn heavy too.
Depleated Uranium was (?still is) used in the tails of Jumbo Jets (Boeing 747 series) to balance it. A Korean freighter 747 crashed near Stanstead airport (UK) as few years ago, but it was so heavy that (alledgedly) most of th DU was never found..............

 
Posital
581600.  Thu Jul 09, 2009 3:52 pm Reply with quote

Depleted uranium is used in weaponry.

Especially in anti-tank shells. When it's alloyed the tip shears off on impact in a way that maintains its pointyness. And the shards of metal simply ignite as they fly off.

Sometimes they're made to resemble metal arrows... or quarrels.

Nasty.

 
PDR
581676.  Thu Jul 09, 2009 5:31 pm Reply with quote

DU used to be a favoured ballast weight in aviation because it was dense (which made the weights smaller) and because it was hard enough to maintain structural properties. Lead weights always come loose over time because the vibration causes them to deform.

DU was common for balance weights on control surfaces, damper weights and the like. But there was a general move in the late 80s/early 90s to elliminate DU from civil aircraft due to toxicity fears, and the weights were mostly replaced with tungsten-based alloys. DU was eliminated from (UK) military aircraft between 1993 and 2000, and as far as I know there are no fast jets that still have DU ballast.

It's possible that some of the RAF's older transport aircraft might still have DU because it was too expensive to remove it. The RAF is still operating VC-10s, and by the time DU went out of fashion there were no civil VC-10 fleets left to pay for the necessary engineering.

There's a bit of trivia here, but I think I'll post it in the random factoids thread.

PDR

 
Janet H
582236.  Fri Jul 10, 2009 12:17 pm Reply with quote

Korean cargo crash was 22rd Dec 1999.
Looks like the Koreans hadn't quite got round to their freighter fleet........
taken from the National Radiological Protection Board (A highly reputable organisation)

http://www.hpa.org.uk/web/HPAwebFile/HPAweb_C/1194947415335

DU Search Called Off
Following the crash of the Korean Airlines 747 cargo aircraft near Stansted
Airport in December 1999 which killed all four crew, there has been an extensive search
for the 22 counterbalance weights made from depleted uranium. They were contained
originally in the aircraft’s tail, but the force of the crash led to complete disintegration of
the tailplane. The subsequent clear-up operation identified 21 intact DU counterbalance
weights, and the search for the missing one involved draining a lake and scraping top soil
from a large area. However, after a 12 month search, the remaining DU counterbalance
has proved elusive and the search has been called off. It is presumed to be buried deep in
soil somewhere near the crash site and therefore presents little hazard.
The Korean Airlines 747 was also carrying some radiopharmaceuticals, including
radioiodine. These were destroyed in the fire following the crash, and were short-lived
isotopes. (Environ Health News, 16(7), 22, 2001.)

 
PDR
582314.  Fri Jul 10, 2009 3:56 pm Reply with quote

It was also found to have been carrying an illegal consignment of mercury thermometers, which is something that causes aircraft to be scrapped. There are two airliners that I know of which are currently in the boneyard in Arizona because they had mercury in their cargos. One of them has less than 2,000 hours on the clock (which is "showroom condition" for an airliner).

The consignee for one of them was identified and served 10 years of a 20 year sentence.

PDR

 
Janet H
582315.  Fri Jul 10, 2009 3:58 pm Reply with quote

PDR wrote:
It was also found to have been carrying an illegal consignment of mercury thermometers, which is something that causes aircraft to be scrapped. There are two airliners that I know of which are currently in the boneyard in Arizona because they had mercury in their cargos. One of them has less than 2,000 hours on the clock (which is "showroom condition" for an airliner).

PDR


Wimpers quietly. Mercury and aluminium not a good combination, I recall (distantly)

Mercury - now there's a really loopy heavy metal. Iron floats on it.

 
Ion Zone
582324.  Fri Jul 10, 2009 4:16 pm Reply with quote

Quote:
Sometimes they're made to resemble metal arrows... or quarrels.


That's the French Arrow (It was invented in England.)

 
Efros
582359.  Fri Jul 10, 2009 5:04 pm Reply with quote

Is that a throwing arrow you are talking about or a sabot round. The throwing arrow is variously called a Swiss arrow, Dutch arrow, French arrow, Yorkshire arrow and indeed a Gypsy arrow. The principle is similar to that used by the woomera or atlatl, except a string or thong is used to prolong the application of force to the arrow.

 
PDR
582361.  Fri Jul 10, 2009 5:06 pm Reply with quote

Janet H wrote:
Wimpers quietly. Mercury and aluminium not a good combination, I recall (distantly)


Indeed. Even the vapour is enough to disqualify the alloys in the aircraft structure.

PDR

 
Efros
582363.  Fri Jul 10, 2009 5:09 pm Reply with quote

The problem there is that the mercury is a cyclic corrosive agent. There is a cycle of mercury + aluminium giving amalgum, the amalgum oxidizes in the atmosphere to release mercury and aluminium oxide, the mercury goes on to combine with more aluminium and so the cycle goes on.

 

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