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Published 1992 | public
Journal Article

Magnetite in Human Tissues: A Mechanism for the Biological Effects of Weak ELF Magnetic Fields


Due to the apparent lack of a biophysical mechanism, the question of whether weak, low-frequency magnetic fields are able to influence living organisms has long been one of the most controversial subjects in any field of science. However, two developments during the past decade have changed this perception dramatically, the first being the discovery that many organisms, including humans, biochemically precipitate the ferrimagnetic mineral magnetite (Fe_(3)S_4). In the magnetotactic bacteria, the geomagnetic response is based on either biogenic magnetite or greigite (Fe_(3)S_4), and reasonably good evidence exists that this is also the case in higher animals such as the honey bee. Second, the development of simple behavioral conditioning experiments for training honey bees to discriminate magnetic fields demonstrates conclusively that at least one terrestrial animal is capable of detecting earth-strength magnetic fields through a sensory process. In turn, the existence of this ability implies the presence of specialized receptors which interact at the cellular level with weak magnetic fields in a fashion exceeding thermal noise. A simple calculation shows that magnetosomes moving in response to earth-strength ELF fields are capable of opening trans-membrane ion channels, in a fashion similar to those predicted by ionic resonance models. Hence, the presence of trace levels of biogenic magnetite in virtually all human tissues examined suggests that similar biophysical processes may explain a variety of weak field ELF bioeffects.

Additional Information

© 1992 Wiley-Liss, Inc. Issue published online: 19 OCT 2005; Article first published online: 19 OCT 2005. Supported by in part by NIH grant GM-41635 and the Electric Power Research Institute (EPRI) contract RP2965-8. We thank C. Rafferty and J.J. Hopfield for helpful discussions. Contribution 5096 of the Division of Geological and Planetary Sciences of the California Institute of Technology.

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August 22, 2023
October 23, 2023