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?
It seems like your question boils down to a few things:
- Is the blood of a person from Chernobyl radioactive?
- How much radiation would be transferred in the next bite?
- 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.
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.
Really no vector (intermediary agent) "transmits radiation". What happens is, they either
- physically deposit radioactive materials, which then emit radiation, which is absorbed, or else,
- 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.