# Thread: Visulalizing 2 nanograms....i.e. 0.000000002 grams

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## Visulalizing 2 nanograms....i.e. 0.000000002 grams

2 nanograms is how much neonicotinoid poison it takes to kill a honey bee. Hard to visualize isn't it. So... maybe the follwing would be a better perspective.

Assume a healthy hive has 60,000 bees. In Texas, there are about 80,000 hives, so thats 4.8 billion bees (60,000*80,000 = 4,800,000,000).

4.8 billion x 2 nanograms = 9.6 grams (4,800,000,000 * 0.000000002 = 9.6)....and that just about fills 2 tablespoons...

Get it....2 tablespoons of a neonicotinoid could kill every bee in the state of Texas...

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## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

You could also see it from this prospective:
it kills bees at molecular level.
1 mole contains 6*10^23 molecules, Imidacloprid, MW=256, 256g/liter==> 1M imidacloprid; 2 ng of imidacloprid ==> 1.28*10^-12M === > 7*10^(23-12) ==> 7*10^11 -->> 70000000000 molecules per bee.

Honey bee has 960000 neurons, so EACH neuron in bee's tiny brain would be "poisoned" by 70000 molecules of Imidacloprid.

Note - I am horrible at arithmetic, please excuse me if I made any mistake in simple multiplication/division. I would gladly correct my calculation if somebody will find an error. BUT scale of "disaster" is right!

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## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

Originally Posted by jeb532
2 nanograms is how much neonicotinoid poison it takes to kill a honey bee. Hard to visualize isn't it. So... maybe the follwing would be a better perspective.
...
You do realize that neonicotinoids are a class of chemical compounds and that there is no leathal dose for a class of chemicals?

Strike 1

If you are talking about the most used neonicotinoid, you do realize that you are incorrect in your figures?
From Wiki:
Like most insecticides, imidacloprid is highly toxic to bees, with a contact acute LD50 = 0.078 μg a.i./bee and an acute oral LD50 = 0.0039 μg a.i./bee.
Strike 2

You do realize that ther are 1,000 nanograms in a µg? Strike 3... You're outta here! Already.

Oh and you didnt take specific gravity into account for your tablespoon calculation.

Strike 4

Get it? (obviously not)

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## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

Originally Posted by Nabber86
From Wiki:
Like most insecticides, imidacloprid is highly toxic to bees, with a contact acute LD50 = 0.078 μg a.i./bee and an acute oral LD50 = 0.0039 μg a.i./bee.
Well, 0.078 μg x 1000=78 ng and 0.0039 μg x 1000 = 3.9 ng, which is 2x more than in original post, but it could not change the picture - the bottom line is that it is VERY small amount! I do not like your aggressive tone - you sounded rude and uneducated... If you so knowledgeable - just do all right calculations, determine the specific gravity of imidacloprid powder (I want to see how you could do it) and give us YOUR estimate and we'll see how it is different from original post. Be friendly...

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## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

Originally Posted by cerezha
Well, 0.078 μg x 1000=78 ng and 0.0039 μg x 1000 = 3.9 ng, which is 2x more than in original post, but it could not change the picture - the bottom line is that it is VERY small amount! I do not like your aggressive tone - you sounded rude and uneducated... If you so knowledgeable - just do all right calculations, determine the specific gravity of imidacloprid powder (I want to see how you could do it) and give us YOUR estimate and we'll see how it is different from original post. Be friendly...
So a 100 percent error is acceptable? To whom?

Including 4 completey erroneous items (at least 4) in the OP is acceptable? To whom?

And as far as doing the clacs. I pointed out that there is no way to figure out the volume w/o using the SG, so the appraoch was wrong to begin with, besides the value selected for one of the input variables, and the math. It's not up to me to figure out what the OP was trying to present, how he was trying to present it, and then fix it for him. Everything about the post is wrong, period.

Only the uneducated would allow the unacceptable presentaion of data such as this (and I cringe to use the word data) and that offends me.

Sensationalism, faulty data, and faulty appliaction of data is no way to solve a problem. Never has and never will be.

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## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

Originally Posted by cerezha
Well, 0.078 μg x 1000=78 ng and 0.0039 μg x 1000 = 3.9 ng, which is 2x more than in original post...

In the context of killing all of the bees in Texas……

By definition of LD50, 0.0039 μg of imidacloprid would kill only 50% of the bees. So there exists a 100 percent error in your approach. This is unacceptable.

The LD100 of imidacloprid would be much higher than the LD50, so there is a compound error of over 100% in your approach. This is unacceptable.

I have provided everything that you need to calculate how much imidacloprid that it would take to kill all of the honeybees in Texas (on a volume basis). The only 2 missing variables are the SG of imidacloprid and the LD100 of imidacloprid and then to do the calculations correctly this time. I am not going to do this for you.

Sensationalism, faulty data, and faulty appliaction of data is no way to solve a problem. Never has and never will be.

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## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

The calculations are not hard, and it is interesting (and maybe useful?) to be able to visualize these things.

There are many estimates of LD50 for imidacloprid on honey bees, but let's take a published value of 0.008 µg (8 ng) per bee. (http://www.cdpr.ca.gov/docs/emon/pub...clprdfate2.pdf)

A worker bee weighs about 100 mg. Thus the toxicity of imidacloprid to honey bees is 8 ng/100 mg = 0.08 mg/kg, if we use the same units as LD50 for mammals. This is about 600 times more toxic than nicotine, 80 times more toxic than cyanide, 20 times less toxic than ricin, and 8000 times less toxic than botulinum, the most human-toxic compound known. Not quite snake venom, but at the same time no compound with this level of toxicity to humans would be allowed to be freely dispersed into the environment.

The LD50 of imidacloprid to rats (the best proxy for humans) has been estimated at 450 mg/kg. Thus the chemical is over 5000 times more toxic to bees than it is to us. Of course that level of specificity is desirable in an insecticide, but when your livestock happen to be insects that is a problem.

It's not easy for me to visualize 80,000 hives, so I'll stick with one. One hive with 60,000 bees. Killing half the bees in a hive would thus require 480,000 ng, or 0.48 mg of imidacloprid. Seed corn is treated at rates of 0.25 to 1.25 mg per kernel. (http://www.extension.iastate.edu/Cro...406hodgson.htm) At the higher rate, one kernel contains enough imidacloprid to kill half the bees in two full strength hives. At the lower rate it would take two kernels to kill half the bees in one hive.

This analysis of course ignores the fact that bees are affected at dosages much lower than the LD50, and it makes the assumption that the chemical would somehow be distributed equally to all bees in the hive, which is false. But still, corn is planted at the rate of 35,000 seeds per acre, and one or two seeds contain enough imidacloprid to kill a whole hive. Corn planting is a dusty endeavor, and not all of that imidacloprid stays on the seed. That would be enough to scare me if I kept bees in corn country, or at least convince me to move my hives well away from fields during planting time.

I don't know that we need to ban imidacloprid and its related neonic cousins, but we need to realize that from a bee's perspective we are dispensing a chemical 80 times more toxic than cyanide across wide expanses of ag lands adjacent to hives. We definitely need rules (isolation distances and times) to improve coexistence.

Mark

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## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

A worker bee weighs about 100 mg. Thus the toxicity of imidacloprid to honey bees is 8 ng/100 mg = 0.08 mg/kg, if we use the same units as LD50 for mammals. This is about 600 times more toxic than nicotine, 80 times more toxic than cyanide, 20 times less toxic than ricin, and 8000 times less toxic than botulinum, the most human-toxic compound known. Not quite snake venom, but at the same time no compound with this level of toxicity to humans would be allowed to be freely dispersed into the environment.
Using rats as a proxy for humans is an acceptable practice. Comparing mammals to insects in toxicology analysis is unacceptable and downright ludicrous. (In case you didnt know, they use rat proxy for humans because they can't test humans. They regularly do tests any bees, rats, and fat head minnows). Why not save the contorted argument and look up the LD50 for nicotine, cyanide, ricin, bot toxin for honeybees directly?

but we need to realize that from a bee's perspective we are dispensing a chemical 80 times more toxic than cyanide across wide expanses of ag lands adjacent to hives.
Uh, you might want to check and see if cyanide is actually toxic to honeybees before you throw statements like that out there.

But anyway you missed the whole question…

How many tablespoons?
Last edited by Nabber86; 04-09-2013 at 03:13 PM.

9. ## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

I have to agree with Nabber - you say it only would take 2 tablespoons full of really toxic stuff to kill all of the bees in Texas and he proves you you are so so wrong - it would take at least 4 tablespoons - probably heaping tablespoons at that - to kill all of the bees in Texas. You completely lose all credibility and Nabber proves it. Good Job Nabber.

Clearly if it takes ANY MORE than 2 tablespoons of this stuff then it just isn't a problem. Unless they use more than 4 heaping tablespoons in the entire state of Texas - which they don't. Right?

Or was it teaspoons? My head hurts.

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## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

Originally Posted by David LaFerney
As it should because you have no concept of exposure pathway(s). One simply does not round up the entire bee population of Texas and make them eat 2 tablespoons of imidacloprid. How exactly would that be accomplished?

Just as if I collected all the cyanide in the world, rounded up the entire world population, and made them eat it (party in Jonestown anybody?), it would kill all of the people in the world. Big deal.

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## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

Originally Posted by David LaFerney
I have to agree with Nabber - you say it only would take 2 tablespoons full of really toxic stuff to kill all of the bees in Texas and he proves you you are so so wrong - it would take at least 4 tablespoons....
To be safe (from Nabbler insinuations) I would propose 8 tablespoons and I would add 2 more to make sure that specific gravity of the powder would not affect the final result. So, 10 tablespoons shall kill for sure all bees in Texas! Yes, horrible, 500% error! Now, there is a problem- how we could evenly distribute 10 tablespoons of nasty stuff over entire Texas to kill ALL bees in our virtual (really?) experiment?

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## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

Comparing mammals to insects in toxicology analysis is unacceptable and downright ludicrous.
All I did was to convert the LD50 for bees (8 ng/bee) into per weight units (0.08 mg per kilogram of bee weight) using the known weight of an average worker bee. Thus IF imidacloprid were as toxic to mammals as it is to bees, it would have an LD50 of 0.08 mg/kg, which can be compared to other mammal-specific LD50's. Clearly it isn't that toxic to mammals (as I clearly pointed out), but I'm using the comparison to make the valid point that from a bee's perspective imidacloprid is a very toxic chemical, right up there with ricin and cyanide.

And if you must know, imidacloprid has a density of 1.543 g/cm3
(http://pmep.cce.cornell.edu/profiles...oprid-ext.html)

Thus the 0.48 mg required to kill 50% of the bees in one strong 60,000-bee hive would occupy a volume of 0.00031 cm3. One tablespoon is 14.79 cm3, so one full tablespoon of imidacloprid could deliver an LD50 dose to 47,700 of our 60,000-bee hives.

If you want to be really picky that is for crystalline imidacloprid. Powder has a lower packing density, so the volume would be slightly different.

I'm not trying to fear-monger and say that neonics are responsible for all of our bee problems. Just pointing out that there is no chemical with anywhere near this level of toxicity to humans that is in widespread use.

One kilogram of cyanide (rat LD50: 6.4 mg/kg) could theoretically kill 1040 75-kilogram humans.
One kilogram of imidacloprid (bee LD50: 8 ng/bee = 0.08 mg/bee kg) could theoretically kill 83,000 75-kilogram bee-masses. That's about 63 billion bees, or one million strong hives.

I realize that neonics are a hot political topic these days, with lots of misinformation on both sides. But we can't lose sight of the fact that these chemicals are exceptionally toxic to bees, and that any guidelines that minimize bee exposure can only help beekeepers.
Last edited by Luterra; 04-09-2013 at 03:52 PM.

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## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

Originally Posted by cerezha
Now, there is a problem- how we could evenly distribute 10 tablespoons of nasty stuff over entire Texas to kill ALL bees in our virtual (really?) experiment?
You forgot the part were you would have to make the eat it.

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## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

Originally Posted by Luterra

Thus IF imidacloprid were as toxic to mammals as it is to bees, it would have an LD50 of 0.08 mg/kg, which can be compared to other mammal-specific LD50's.
Then why on earth are you making that comparison? You are not even going across species of mammals (rats to mammals), you are crossing from arthropods to mammals.

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## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

Originally Posted by Nabber86
You forgot the part were you would have to make the eat it.
I am sorry - it is YOUR part. You need to read... the original post just intended to illustrate the toxicity of stuff in everyday "units"... it has no intention to do any scientific conclusions... and you are just trolling here in aggressive manner...

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## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

Originally Posted by Nabber86
Then why on earth are you making that comparison? You are not even going across species of mammals (rats to mammals), you are crossing from arthropods to mammals.
It's not a perfect comparison, but neither is it entirely invalid. Some toxins, like cyanide, are more or less equally toxic to all life. Cyanide in particular blocks cells' ability to use oxygen, and as this oxygen requirement is ubiquitous across plants, animals, and fungi, the killing dose is primarily dependent on body mass. Other toxins, like imidacloprid or herbicides, bind specifically to proteins found in particular organisms, rendering them thousands of times more toxic to target organisms than to non-target organisms. Neonicotinoids are insect-specific. Bees, being insects, are members of their target group. Imidacloprid is approximately as toxic to bees as ricin is to humans. Both are neurotoxins that respectively target insect and mammalian nerve receptors.

17. ## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

Originally Posted by Nabber86
As it should because you have no concept of exposure pathway(s).
golly, you've exposed me - I'm an ignorant son of a bee keeper. Along with everyone else it would seem. Would you please enlighten us further? Then we can all quibble about the maths of what really is a little or a lot.

You know, personally I don't know if the issue is neonics or not. Clearly you think not. There are both shrill and reputable voices on both sides. But I do know this - it does not matter if it takes two teaspoons or two truckloads of chemicals to kill all of the bees in Texas. But something is doing it. And either Amt would not be very much in the big picture.

Texas is a big state you know.

Do you by any chance work for Bayer?

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## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

" Hard to visualize isn't it." No, not particularly. We know the problem, how can we help you solve it?

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## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

Originally Posted by David LaFerney
Would you please enlighten us further? Then we can all quibble about the maths of what really is a little or a lot.

You know, personally I don't know if the issue is neonics or not. Clearly you think not?
"Route of exposure" is how a toxic substance gets into an organism; ingestion, dermal, contact, inhalation.

"Exposure Pathway" is how the toxic substance travels to the organism; air , water, sediment.

We all know that neonics are highly toxic to bees, through the route of direct ingestion. A study proving this has been posted numerous times on beesource and is not disputed by anyone, including myself. So we know one thing: bees have to eat neonics to die. Ingestion is the route of exposure. As far as I know, spraying bees with neonic (direct contact) has not been proven to be toxic, but it is probably safe to assume that it is so. So assume for now that bees have to eat neonics or be directly sprayed with them to die (gave you a gimme there). As a side note, please be aware that the LD 50 is different for different routes of exposure and can vary widely.

The only "exposure pathway" that has thus been demonstrated so far is mixing neonics with some type of food that the bees will eat. The study used HFCS as a pathway. You could say that the pathway included humans purchasing neonics, mixing it with HFCS, and hand carrying over to the bees. The pathway in the study was very short and really defaults to bees eating neonics. As a side note, the more complicated and tortuous the pathway the less valid.

In short, what does all of the data show? Neonics are highly toxic to bees and if ingested, they die. Nothing more nothing less. Stating that x mass of neonics can kill y number of bees is completely meaningless outside of the context of exposure routes and pathways. Please note also that this is the only point that I am trying to make in the context of this thread!

Do I think that neonics are the cause of CCD? Could be, but the the available data says no. Show me the route and exposure pathway of neonics as they are used in modern agriculture. As far as I am concerned it doesn't exist. Argue all you want, but the facts do not support you.

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## Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

As a side note, the more complicated and tortuous the pathway the less valid.
I wasn't aware exactly how incredibly toxic neonics are to bees until I did these calculations today. With this level of toxicity, complicated/tortuous pathways must be considered.

If 1/35,000th of the amount of neonics in an acre planted with treated corn seed is enough to kill 60,000 bees, then we need to consider not only direct routes of exposure, but also more complicated ones (e.g. bees picking up imidacloprid dust while in the air, planting dust settling on adjacent blooms, bees collecting pollen from corn plants grown from treated seed, etc.). If neonics were 10- or 100-fold less toxic, these pathways wouldn't be of concern.

It's hard to accidentally ingest enough cyanide to die, but if you had a bottle of ricin all it would take is one breath of wind to send a few particles into the air. And that's unfortunately the level of toxicity we have with neonics and bees.

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