How strong would a magnetic field have to be to kill you?

Radiologist/Biomedical Engineer here. I once did a review of the physiological effects of magnetic fields as was our current understanding in the last decade. in general, things that get altered with sufficiently large magnetic fields: - Cardiac electrical conductivity - Muscular electrical conductivity - Fibrin (protein necessary for clotting blood) meshes get distorted - There is DNA genotoxicity, and mutations start to appear - Diamagnetic effects start taking over (Most extreme demonstration I've seen so far is the levitating frogs and grasshoppers, which seem quite content afterwards, so no ill effects apparent)

Bottom line is that pretty much everything in our bodies that contains water can be affected by a sufficiently large static magnetic field. Some critical physiological processes may get disrupted way earlier than the atomic distortions cited in the article, so I believe much less than 100k Tesla would be needed to kill a person.

I think that you'd end up with neurological effects before the electrons were ripped out of atoms. I mean, our nervous system is effectively controlled ionic exchange.

I think you would be killed by the diamagnetic properties of water first...

If you can affect water with a small magnet like this: https://www.youtube.com/watch?v=2FvWtEdY4sE

Then a magnetic field of sufficient power would probably kill you long before the effects described in the article. I'm amazed that someone other than me has thought about this!

The sci-fi book Blingsight by Peter Watts explores humanity's 1st encounter with an alien object that contains extremely powerful magnetic fields. Has all sorts of interesting consequences.

Has anyone looked at the effects not on particles, but on changes to reactivity in the presence of magnetic fields? You don't need to rip apart molecules to kill us. Make certain reactions a little more or less likely to occur and we stop functioning.

I have seen some discussion of how heavy water could be lethal if it were to replace all of a body's water based on its very slight differences in reactivity.

Something called Transcranial Magnetic Stimulation alters brain activity at about one Tesla (10,000x earth's field). TMS has been shown to induce euphoria, amnesia, and relieve depression. Unclear what stronger magnetic fields could do. A ten Tesla magnet can levitate a small animal.

Relatively weak MFs could kill as an indirect result of the injury: http://mentalfloss.com/article/18405/mri-magnet-madness http://boards.straightdope.com/sdmb/showthread.php?t=544233

The effect depends on field signal characteristics (frequency, amplitude, wave shape), duration of exposure, genetics and metabolism. Some bacteria can be negatively affected even by 10 mT. In clinical trials people were "safely" exposed to up to 3 T.

Wouldn't iron in blood be affected well before this point though?

Would you be mechanically compressed by the field before your atoms deform?

3 Tesla Magnetic field MRI's are now common and I have heard rumors of up to 7T machines in the works: http://www.healthdiagnostics.com/svc_hi_field.php

I've always wondered what would happen if you got trapped in the Superconducting Super Collider.

Terminator 3 Particle Accelerator Scene

https://www.youtube.com/watch?v=KKFnsFFdPh8

I think a lot of new technologies will emerge when we can routinely control very large magnetic fields. I just think the technological implications are largely unexplored.

What about semipermiatic structures such as the blood brain barrier? According to The Internet(tm), permeability in rat brains is affected by a mere 0.1T.

So I guess this means we are safe from Magneto :)

earth is a very big magnatic field and it wont kill us. well i think we need a trillian times stronger magnatic field than earth to kill human.

I've wondered about this exact question for a while now.

If I were to become a lunatic dictator, this is how I would deal with dissidents. (Disclaimer: I have no intention of ever becoming a lunatic dictator!)