Imagine that a mosquito just bit a person from Chernobyl (for example) and hypothetically it went far far away from chernobyl's radiation ratio and bit another person. Can this mosquito transmit radiation from the 1st person to the 2nd one?

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    $\begingroup$ You might want to take this question to Physics SE. $\endgroup$
    – Tom
    Jun 13, 2021 at 5:50
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    $\begingroup$ Mosquitos collect about 3 mg of blood per bite. Exposure to 2 mg U/m3 (as pure uranium hexafluoride) 6 hours/day for 30 days caused 5, 20, and 80% mortality in guinea pigs, dogs, and rabbits, respectively (Spiegl 1949). You would probably be exposed to higher amounts of radiation from an old CRT television than from a mosquito bite. $\endgroup$
    – Codosaur
    Jun 13, 2021 at 12:20
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    $\begingroup$ @Tom The fact that a question can be asked on another stack does not mean that this question is not suitable for WB.SE. $\endgroup$
    – Otkin
    Jun 13, 2021 at 19:38
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    $\begingroup$ yes it can transmit, no not a hazardous quantity over a long distance. if mosquito pick up a dangerous contaminated blood, the mosquito will die of it before it gets far. if mozzie does not die, the dose is not dangerous for a human, who is several billion times larger than the doze the mozzie will deposit when biting again, and will dilute the dose correspondingly. $\endgroup$
    – PcMan
    Jun 13, 2021 at 20:33
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    $\begingroup$ @Otkin The help center specifically states: "Must include context: What are you trying to accomplish? Context gives people writing answers an idea of what your end state will look like and why you want to get there.". This question has no worldbuilding context at present, voting to close as 'needs details and clarity'. $\endgroup$ Jun 13, 2021 at 20:33

3 Answers 3


It seems like your question boils down to a few things:

  1. Is the blood of a person from Chernobyl radioactive?
  2. How much radiation would be transferred in the next bite?
  3. Is this a dangerous amount?

A living person is unlikely to have blood that is appreciably radioactive (source: they aren't dead). But let's assume that they are an average fleeing evacuee from the Chernobyl disaster, with a dose of 30 mSv (source). Let's further assume that this dose came entirely from particles in the bloodstream (inaccurate, but a drastic overestimate at least). The normal background dose over a year is about 3 mSv (source), so we could say that if they received that dose all in one day then their blood is about 3000 times more radioactive than normal.

A half-full mosquito would have something like 2-3 microliters of blood (source). Assuming that 1% of this blood ends up in the next person that is bitten, the mosquito will end up transferring about 30 nanoliters of 3000-times-more-radioactive blood into the next person.

This is about 0.6 millionths of a percent of their blood, which would translate to an increase over background radiation of 0.0018%. The bite itself would be more harmful than the radioactivity.

  • $\begingroup$ How did you get to the 1% in "1% of this blood ends up in the next person that is bitten"? $\endgroup$ Jun 14, 2021 at 0:00
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    $\begingroup$ @PaŭloEbermann - 1% was a complete guess. My reasoning was, if nothing transferred, then mosquito-transmitted diseases (not mosquito-borne) wouldn't really be a thing, but if a significant amount transferred, then that's an inefficiency for the mosquito and would be evolutionarily selected against. 0% would give nothing transmitted, 100% would give an increase in background radiation of 0.18%, which is still negligible. $\endgroup$
    – IronEagle
    Jun 14, 2021 at 0:52
  • $\begingroup$ @IronEagle mosquito transmitted diseases tend to be transmitted through the saliva of the mosquito, which is injected into the bite wound to prevent clotting (the saliva contains an anti-clotting agent). A tiny amount of blood may of course be left on the proboscus from the previous bite but that's not the primary vector. $\endgroup$
    – jwenting
    Jun 14, 2021 at 7:04
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    $\begingroup$ Re: A living person is unlikely to have blood that is appreciably radioactive (source: they aren't dead) - perhaps it would fit the OPs story for the mosquito to have bit someone who had just died (perhaps even while the mosquito was landing on them!) from a massive radiation overdose, allowing for higher concentration? Although in that case the mosquito itself would probably have got a similar dose of radiation from its own direct exposure to the event, so some explanation would be needed why that wasn't fatal to the mosquito too. $\endgroup$
    – Steve
    Jun 14, 2021 at 7:17
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    $\begingroup$ @Steve yes and no, part of that blood meal would be turned into those things, but a lot will (just as with our food) end up being discarded. In fact a lot of insects don't use any of the food they take in as adults for any other purpose than creating eggs (and sperm for males, but male mosquitoes don't bite, they're vegetarians). I'm not sure if that's strictly true of mosquitoes though. $\endgroup$
    – jwenting
    Jun 14, 2021 at 7:46


Smaller bits of, for example, plutonium can be devastating to a person's health over time. It is not impossible for blood to be so contaminated that it can give lethal doses to a person in a mosquito. As I understand it, it can be depressingly small what can eventually kill you.

Then again, very much no

The person they would need to bite would either just put a needle with nuclear stuff into his or her bloodstream, while the mosquito needs to drink just downstream of the needle. Any other scenario the person they bite is most likely already dead. It is just way too much radiation to have floating homogeneous in the bloodstream. Mosquitoes don't bite dead people. They sense the veins and such from the blood pressure coursing through, allowing them to bite in such a way that the pressure fills them up automatically (and not explode them). A dead person doesn't have the blood pressure that makes them bite.

Insects generally have a higher tolerance to nuclear materials, but if they get something that is lethal over decades for a mammal as large as a human, it is most definitely bad for the incredibly small mosquito. Likely it'll die of direct radiation poisoning before it reaches any distance.

  • $\begingroup$ your assertion that tiny amounts of Plutonium are lethal is incorrect in itself. The amount certainly isn't microscopic. Plutonium's toxicity is on a level similar to that of Lead, less than that of Cadmium, while in its metallic form. The killer here is Plutonium Oxide dust, which is very bad news when inhaled. A few atoms of Plutonium entering the blood stream through an insect bite aren't going to harm you. $\endgroup$
    – jwenting
    Jun 14, 2021 at 7:06
  • $\begingroup$ @jwenting I have to disagree. As you say, Plutonium in the air, settling in the lungs, is very dangerous. We skip the lungs and go directly into the bloodstream, where the Plutonium has more opportunities to do harm. Alpha radiation also doesn't interact sometimes with the air, as it would do from the lungs. That being said, I agree with you that the mosquito cannot harm the human. The conditions to bring enough into the bloodstream are ludicrous, which I pointed out in the second section. Not to mention the mosquito generally doesn't bite again, as it has the required ingredients for eggs. $\endgroup$
    – Trioxidane
    Jun 14, 2021 at 12:44
  • $\begingroup$ Sure, if you were to directly inject a significant amount of radioactive material into the body you'd get radiation exposure. This is what happens with some forms of cancer treatment as well. But the main toxicity of Plutonium (due to its reasonably long half life) isn't from radiation but checmical toxicity. $\endgroup$
    – jwenting
    Jun 15, 2021 at 7:35

Really no vector (intermediary agent) "transmits radiation". What happens is, they either

  1. physically deposit radioactive materials, which then emit radiation, which is absorbed, or else,
  2. they are radioactive or carry radioactive materials, which are not deposited, but emit radiation, which is absorbed.

Therefore the OP's mosquito must in effect do one of these things:

  • deposit radioactive dust/particles it picked up
  • inject radioactive blood or surface contaminants it acquired when feeding
  • be radioactive itself and have that radioactivity absorbed

The problem is, radioactive materials mostly would be negligible for the tiny amount a mosquito could transfer. Even plutonium, notoriously toxic, has studies suggesting that it isn't quiiiiiiiite as toxic as many believe (Source: Wikipedia #toxicity). Also if there's enough to endanger a human, its unclear whether the mosquito will survive to bite.


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