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  1. #1
    Join Date
    Feb 2011
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    Venus, Texas, USA
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    Default 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...

  2. #2
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    Default 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!
    Серёжа, Sergey

  3. #3
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    Default Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

    Quote Originally Posted by jeb532 View Post
    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 g? 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)
    Honey Badger Don't Care ಠ_ಠ ~=[,,_,,]:3

  4. #4
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    Default Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

    Quote Originally Posted by Nabber86 View Post
    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...
    Серёжа, Sergey

  5. #5
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    Default Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

    Quote Originally Posted by cerezha View Post
    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.
    Honey Badger Don't Care ಠ_ಠ ~=[,,_,,]:3

  6. #6
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    Default 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 g (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

  7. #7
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    Default 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 04:13 PM.
    Honey Badger Don't Care ಠ_ಠ ~=[,,_,,]:3

  8. #8
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    San Mateo, Ca, USA
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    Default Re: Visulalizing 2 nanograms....i.e. 0.000000002 grams

    it also ignores the fact that bees don't eat corn kernels

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

    Quote Originally Posted by cerezha View Post
    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.
    Honey Badger Don't Care ಠ_ಠ ~=[,,_,,]:3

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