[neilep (OP)]

Just curious !


What are the top 5 most potent deadliest poisons ?..

Are they natural ?..manufactured ? airborne ?..liquid ?..powder ?

I would class potency by the least amount required to cause death.

[lgic]

LD₅₀is the way that pharmacologists measure lethality. It's the amount of a toxin that must be given in order to cause death in 50% of the animals it was given to. Tetrodotoxin, botulinum toxin and ricin all have LD₅₀values around 1 ng/kg (depending on exact form of the toxin, route of adminstration and species).
Tetrodotoxin is associated with Fugu poisoning (Fugu is pufferfish sushi) and zombies. See the movie and/or book called the Serpent and the Rainbow for a popular treatment of the story, or Wade Davis's books & article for more serious information. Botulinum toxin is found in improperly made or sealed canned goods. Ricin is man-made.

And I'd like to take a moment to point out that I am a neuropharmacologist, not a bad sushi chef, homecanner or terrorist.

[ukmicky]

Please tell me how does one decide that they want to become become a neuropharmacologist.

Were you a pharmacist who decided there was more to life than sitting behind a counter in a chemist shop.  [] []

I wonder who's got the most interesting job on the forum.

[lgic]

No, I think I'd have to go back to school for a few years before I'd be qualified to dispense drugs to the public, at least in the US.

I work in lab where we try to figure how neurotransmitter receptor/ion channels function. Some of the nasty neurotoxins are very useful tools for us in our experiments.

But this totally off your original question - maybe it would be a good thread on its own.

[neilep (OP)]

LD₅₀is the way that pharmacologists measure lethality. It's the amount of a toxin that must be given in order to cause death in 50% of the animals it was given to. Tetrodotoxin, botulinum toxin and ricin all have LD₅₀values around 1 ng/kg (depending on exact form of the toxin, route of adminstration and species).
Tetrodotoxin is associated with Fugu poisoning (Fugu is pufferfish sushi) and zombies. See the movie and/or book called the Serpent and the Rainbow for a popular treatment of the story, or Wade Davis's books & article for more serious information. Botulinum toxin is found in improperly made or sealed canned goods. Ricin is man-made.

And I'd like to take a moment to point out that I am a neuropharmacologist, not a bad sushi chef, homecanner or terrorist.

THANK YOU Lgic,

...and if you haven't been welcomed here already...WELCOME....enjoy the site.

[iko]

I perfectly know the most dangerous
and lethal poison for human beings:
No powder, no liquid, no GAS...
Its name begins with an I
...and it's not
iko

http://currentera.com/blog/wp-content/ignorance.jpg

[neilep (OP)]

This is true !!!..just one little ignorant mistake can cost thousands of lives...

[realmswalker]

also, there are various radioactive "poisons" that cause death over a few days and require just a few molecules to be in the body, they were used to kill that one russian guy not to long ago.

[neilep (OP)]

also, there are various radioactive "poisons" that cause death over a few days and require just a few molecules to be in the body, they were used to kill that one russian guy not to long ago.

yes, THANK YOU for this.

Does the body get buried in a lead coffin !! Presumably the radiation is still there ?

[realmswalker]

you would think that being buried 6 feet under ground would provide adequate insulation.... isnt it like 3 feet of earth or 10 feet of water is enough to protect you from the radiation of a nuclear bomb?

[lightarrow]

In that case (Polonium 210) the radioactivity is in the form of alpha particles (helium nuclei) which are stopped completely from a fraction of millimeter of matter. Inside a human body, however, alpha particles react with some organic substances forming very toxic compounds.

[neilep (OP)]

In that case (Polonium 210) the radioactivity is in the form of alpha particles (helium nuclei) which are stopped completely from a fraction of millimeter of matter. Inside a human body, however, alpha particles react with some organic substances forming very toxic compounds.

THANK YOU Lightarrow !

I asked because I am sure I heard it mentioned on the news. Thanks for your information

[neilep (OP)]

you would think that being buried 6 feet under ground would provide adequate insulation.... isnt it like 3 feet of earth or 10 feet of water is enough to protect you from the radiation of a nuclear bomb?

You would think so wouldn't you ?..But I am sure I have heard of cases where the body has had to put in a lead lined coffin !!..unless !!..I'm mixing reality with fiction !!...

[huwston]

polonium emits a alpha particles and is blocked by paper,, but if swallowed it cannot escape the body, this makes it the worst type of radiation to get inside you.

dont know about the toxins it produces though, when mixed with organic substances.

i doubt a lead coffin would be necessary though.

[profnick]

Whoops Lgic  "Ricin is man-made."  Fraid not; Ricin is extracted from the castor bean plant Ricinus communis and was the natural toxin used to kill the Bulgarian diplomat Gyogi Markov, (many years ago) when it was embedded in a pellet on the pointy end of an umbrella which was jabbed into his leg. Ricin  is much less toxic when ingested because it is a protein and is metabolised, but eating raw or undercooked castor beans can still make you very ill due to the ricin content.

[lgic]

You are correct that it comes from a natural source, but without human interference, it doesn't become the incredibly potent toxin we know as ricin. Undercooked castor beans aren't in the same category of deadliness as the purified ricin. Just a matter of degree, I know. But a matter of degree is all that separates useful drugs from poisons. Look at what they've done with botulinum toxin - what used to be a reason to throw out dented cans of food has become expensive BoTox for wrinkles!

[profnick]

lgic,
I think your distinction is a little spurious. Ricin exists as ricin in the plant and needs no chemical intervention though it does require extraction. In fact ricin is more easily extracted from the plant than your examples of Botulinum and tetrodotoxin from the bacterium and fish respectively.
Thus all three examples you give are most definitely natural toxins.
Other than that we are in heated agreement. I'm glad you posted the issue of LD50 and dose/response as this is something that usually, and often conveniently, gets forgotten by those who wish to scaremonger.
I published a monograph a few years back called "drugs from bugs" in which I drew a parallel between the significant use of plants in the development of pharmaceuticals, (about 60% of current pharmaceuticals derived in some measure from plants), with the vast yet untapped possibilities to do the same from the invertebrata which make up a much larger proportion of biodiversity. I notice from a quick Google that this phrase and the research concept seems to be taking off....good job I'm retired.