Re: Can magnetism kill a person?

David:

You ask:

If a magnet were strong enough and large enough, would it 'pull' (attract) nearly all the iron in the human blood and human body to one side of the body surface sufficiently to cause death or serious injury? Has anyone ever died of this cause?

First, I am assuming that you re talking about a static (direct current, DC) magnetic field like that produced by the Earth.

Static magnetic fields are generally measured in Tesla (T), milliTesla (mT), and microTesla (microT, µT) where:

In the US, fields are sometimes still measured in Gauss (G) and milliGauss (mG), where:

The Earth's natural field ranges from 0.03 to 0.07 mT, depending on location.

The first part of the answer is that the iron in human blood is not of a form that is directly affected by a static magnetic field. So you would not expect any effects.

The second part of the answer is that scientists have actually looked for effects of strong magnetic fields on hematology (hematology is the study of blood and blood forming tissues). In such studies animals have been exposed for short and long times to fields as high as 2 tesla (T), and no consistent effects have been seen.

People working around 4 T magnets have reported vertigo and nausea. Vertigo is an illusion that the world is revolving around you or that you are revolving in space -- it is not quite the same as dizziness. Interestingly this happens mostly when they make rapid head movements in the field -- the effect goes away when they stay still.

Sources:

• CI Kowalczuk et al: Biological Effects of Exposure to Non-ionizing Electromagnetic Fields and Radiation. I. Static Electric and Magnetic Fields (NRPB-R238), National Radiation Protection Board, Chilton, (1991).
• M Osbakken et al: A gross morphologic, histologic, hematologic, and blood chemistry study of adult and neonatal mice chronically exposed to high magnetic fields, Magnet. Reson. Med. 3:502-517 (1986).
• JF Schenck: Health and physiological effects of human exposure to whole-body four-Tesla magnetic fields during MRI, Ann. NY Acad. Sci. 649:285-301 (1992).
• National Radiation Protection Board: Restrictions on human exposure to static and time varying electromagnetic fields and radiation, Document of the NRPB 4 (5):1-69 (1993).
• MA Stuchly: Human exposure to static and time-varying magnetic fields, Health Phys. 51:215-225 (1986).

John Moulder
Radiation Biologist
Medical College of Wisconsin