# Smallest thing that can kill you?
**URL:** https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179
**Category:** In My Humble Opinion
**Created:** [November 18, 2013, 3:07pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179 "2013-11-18T15:07:25Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@Jackknifed\_Juggernaut](https://boards.straightdope.com/u/Jackknifed_Juggernaut)
#### Post date: [November 18, 2013, 3:07pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/1 "2013-11-18T15:07:25Z")
This question came to mind as I watched the distressed look on my 300+ pound friend hold a tiny little shot of Patron. I know he hates shots - they make him vomit - but someone bought an unannounced round. The only excuse my friend could come up with was that he could potentially die from that shot. The sheer absurdity of a tiny little shot potentially killing this gargantuan human caused an outburst of laughter from those who heard. But I digress…
So what’s the smallest individual thing that can kill an average-sized adult human being? I know radiation and viruses are tiny, but it would take many of these particles to kill someone. Bonus points for the smallest thing known to have actually killed someone.
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### Author:  [@chrisk](https://boards.straightdope.com/u/chrisk)
#### Post date: [November 18, 2013, 3:12pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/2 "2013-11-18T15:12:28Z")
Apparently 50 nanograms of Polonium 210 is a ‘Median lethal dose.’ [wiki cite.](http://en.wikipedia.org/wiki/Poisoning_of_Alexander_Litvinenko)
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### Author:  [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)
#### Post date: [November 18, 2013, 3:23pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/3 "2013-11-18T15:23:00Z")
1 cosmic ray hitting the right cell and causing cancer. In the end, most radiation-induced cancers probably start with that one chance encounter/mutation/'toma.
So does your friend really have some lethal allergy or was it an excuse not to drink? (Your post isn’t quite clear.)
Frankly, I would have said (accurately), “Well, I’ll toss this down to be sociable if you insist, but I hate even the smell of tequila so much I will likely projectile-vomit all over y’all. Bottoms up…”
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### Author:  [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)
#### Post date: [November 18, 2013, 3:54pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/4 "2013-11-18T15:54:15Z")
A few micrograms of peanut dust (provided you’re severely allergic).
Barring allergies, there are some small but lethally venomous animals out there.
A single cone snail sting [can cause death in five minutes.](http://en.wikipedia.org/wiki/Conidae#Cone_snail_venom_characteristics_and_biotech)
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### Author:  [@Jackknifed\_Juggernaut](https://boards.straightdope.com/u/Jackknifed_Juggernaut)
#### Post date: [November 18, 2013, 4:48pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/5 "2013-11-18T16:48:39Z")
> [@Amateur\_Barbarian](#):
>
> …So does your friend really have some lethal allergy or was it an excuse not to drink? (Your post isn’t quite clear.)…
Just a bad excuse, although there would be about a 50% chance of vomiting shortly thereafter. He told everyone he was on a medication that could create a life-death issue if he did the shot. Of course, he drank plenty of beer already which is why no one believed him.
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### Author:  [@SandyHook](https://boards.straightdope.com/u/SandyHook)
#### Post date: [November 18, 2013, 5:15pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/6 "2013-11-18T17:15:23Z")
The cosmic ray thing is a bit of a reach, IMO. While one **could** trigger a cancer you are subject to gazillions of them per day with little or no problem. So they are only very rarely a real problem.
the Polonium 210 is the probable winner I guess. 50 nano grams is about as close to nothing as you can get yet it’s fatal half the time.
As far as quasi-living things go I’d suggest any of a number of viruses.
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### Author:  [@Peaton\_of\_peat](https://boards.straightdope.com/u/Peaton_of_peat)
#### Post date: [November 18, 2013, 5:38pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/7 "2013-11-18T17:38:23Z")
[Botulinum toxin](http://en.wikipedia.org/wiki/Botulinum_toxin) is pretty close to polonium, with an LD[sub]50[/sub] of 1-2 nanograms per kilogram. For that matter, a single bacterial spore surviving the sterilization process will grow into a colony and poison your canned food. Unlike polonium, acute botulinum intoxication is relatively easy to treat and reverse if diagnosed, but it’s still not pleasant.
Also unlike polonium, it’s intentionally injected into people’s faces to make them look prettier.
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### Author:  [@Smeghead](https://boards.straightdope.com/u/Smeghead)
#### Post date: [November 18, 2013, 5:41pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/8 "2013-11-18T17:41:27Z")
A single virus could kill you, if it got lucky. Ditto for a single photon.
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### Author:  [@Oredigger77](https://boards.straightdope.com/u/Oredigger77)
#### Post date: [November 18, 2013, 6:03pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/9 "2013-11-18T18:03:53Z")
Just to be a bit different the 2mm Kolibri round only weights 0.2 g and it could kill from close enough in the right spot.
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### Author:  [@Scubaqueen](https://boards.straightdope.com/u/Scubaqueen)
#### Post date: [November 20, 2013, 5:59pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/10 "2013-11-20T17:59:44Z")
In the animal world - specifically the ocean in this case - not counting the tendrils, which are about 3 meters, the box jellyfish’s body is a mere ten inches across.
You DO NOT want to encounter one of them. EVER.
I’m sure one of you can come up with something equally lethal and even smaller on land.
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### Author:  [@oft\_wears\_hats](https://boards.straightdope.com/u/oft_wears_hats)
#### Post date: [November 20, 2013, 6:58pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/11 "2013-11-20T18:58:12Z")
A single virus can’t kill a human on its on, not without reproducing. Can it?
However, isn’t there a species of amoeba that can kill a human by eating its way up a sinus nerve path and into the brain? Can’t find a link at the moment, but I thought a single amoeba could kill a host this way, if it got access to the right nerve.
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### Author:  [@BrotherCadfael](https://boards.straightdope.com/u/BrotherCadfael)
#### Post date: [November 20, 2013, 7:18pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/12 "2013-11-20T19:18:05Z")
50 nanograms is pretty small - but [here’s](http://www.e-reading.biz/chapter.php/73047/20/Heinlein_-_Expanded_Universe.html)a short Heinlein story where someone died of something that weighed even less.
Based on a real-life incident.
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### Author:  [@gallows\_fodder](https://boards.straightdope.com/u/gallows_fodder)
#### Post date: [November 20, 2013, 8:15pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/13 "2013-11-20T20:15:07Z")
[Prions](http://en.wikipedia.org/wiki/Prion) come to mind. Good luck trying to get rid of them!
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### Author:  [@Cat\_Whisperer](https://boards.straightdope.com/u/Cat_Whisperer)
#### Post date: [November 20, 2013, 8:20pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/14 "2013-11-20T20:20:43Z")
> [@Scubaqueen](#):
>
> In the animal world - specifically the ocean in this case - not counting the tendrils, which are about 3 meters, the box jellyfish’s body is a mere ten inches across.
>
> You DO NOT want to encounter one of them. EVER.
>
> I’m sure one of you can come up with something equally lethal and even smaller on land.
For one of the smallest, deadliest things you can grow in your back yard, I nominate the [castor bean.](http://www.cbif.gc.ca/pls/pp/ppack.info?p_psn=135&p_type=all&p_sci=comm) Two to four seeds (beans) can kill a child. We’re keeping this in mind for the apocalypse, should things get completely untenable. 🙂
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### Author:  [@Battle\_Pope](https://boards.straightdope.com/u/Battle_Pope)
#### Post date: [November 20, 2013, 9:46pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/15 "2013-11-20T21:46:57Z")
> [@Scubaqueen](#):
>
> In the animal world - specifically the ocean in this case - not counting the tendrils, which are about 3 meters, the box jellyfish’s body is a mere ten inches across.
>
> You DO NOT want to encounter one of them. EVER.
>
> I’m sure one of you can come up with something equally lethal and even smaller on land.
Say “Hi” to the [Irukandji jellyfish](http://en.wikipedia.org/wiki/Irukandji_jellyfish). :eek:
> [@](#):
>
> Irukandji jellyfish are very small with a bell about 5 millimetres (0.20 in) to 25 millimetres (0.98 in) wide (or wider) and four long tentacles, which range in length from just a few centimeters up to 1 metre (3.3 ft) in length.
and
> [@](#):
>
> When properly treated, a single sting is normally not fatal, but two people in Australia are believed to have died from Irukandji stings in 2002…It is unknown how many other deaths from Irukandji syndrome have been wrongly attributed to other causes.
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### Author:  [@SmellMyWort](https://boards.straightdope.com/u/SmellMyWort)
#### Post date: [November 20, 2013, 9:56pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/16 "2013-11-20T21:56:04Z")
What about a blood clot?
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### Author:  [@penultima\_thule](https://boards.straightdope.com/u/penultima_thule)
#### Post date: [November 20, 2013, 10:02pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/17 "2013-11-20T22:02:48Z")
> [@Battle\_Pope](#):
>
> Say “Hi” to the [Irukandji jellyfish](http://en.wikipedia.org/wiki/Irukandji_jellyfish). :eek:
And you don’t even need to be in the water …
[Man stung by irukandji jellyfish while fishing from bulk carrier](http://www.telegraph.co.uk/news/worldnews/australiaandthepacific/australia/6964636/Man-stung-by-irukandji-jellyfish-while-fishing-from-bulk-carrier.html)
> [@](#):
>
> The Filipino ship worker was fishing off the deck of a Singaporean vessel, some 25 metres above sea level, when he was splashed on the face with sea water apparently while reeling in his line.
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### Author:  [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)
#### Post date: [November 20, 2013, 10:29pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/18 "2013-11-20T22:29:56Z")
> [@BrotherCadfael](#):
>
> 50 nanograms is pretty small - but [here’s](http://www.e-reading.biz/chapter.php/73047/20/Heinlein_-_Expanded_Universe.html)a short Heinlein story where someone died of something that weighed even less.
I’d concede that thoughts could kill, but the mechanism of death is something else biological or biochemical.
And no, a single virus can’t kill, but it can start an infection that’s lethal. Not sure if it counts on that basis.
I’ll maintain that a single radioactive particle/ray damaging a cell could be the singlehanded start of a lethal cancer. It’s all in the odds, which is why vastly greater numbers of actual cell damage are needed to be statistically significant.
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### Author:  [@TBG](https://boards.straightdope.com/u/TBG)
#### Post date: [November 20, 2013, 10:30pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/19 "2013-11-20T22:30:13Z")
> [@Cat\_Whisperer](#):
>
> For one of the smallest, deadliest things you can grow in your back yard, I nominate the [castor bean.](http://www.cbif.gc.ca/pls/pp/ppack.info?p_psn=135&p_type=all&p_sci=comm) Two to four seeds (beans) can kill a child. We’re keeping this in mind for the apocalypse, should things get completely untenable. 🙂
What, no Lilly of the Valley?
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### Author:  [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)
#### Post date: [November 20, 2013, 10:55pm UTC](https://boards.straightdope.com/t/smallest-thing-that-can-kill-you/674179/20 "2013-11-20T22:55:08Z")
Dr. Ruth is really small, and she trained as a sniper.
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