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

KIRSCHVINK, S.J.; KOBAYASHI-KIRSCHVINK, A.; DIAZ RICCI, JUAN C.; KIRSCHVINK, S.J.

BIOELECTROMAGNETICS.

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 1992 vol. 1 p. 101 - 113

0197-8462

Due to the apparent lackof a biophysical mechanism, the question of whether weak, low frequency magneticfields are able to influence living organisms has long been one of the mostcontroversial subjects in any field of science. However, two developmentsduring the past decade have changed this perception dramatically, the firstbeing the discovery that many organisms, including humans, biochemically precipitatethe ferrimagnetic mineral magnetite (Fe3O4). In themagnetotactic bacteria, the geomagnetic response is based on either biogenicmagnetite or greigite (Fe,S,). and reasonably good evidence exists that this isalso the case in higher animals such as the honey bee. Second, the development ofsimple behavioral conditioning experiments for training honey bees todiscriminate magnetic fields demonstrates conclusively that at least oneterrestrial animal is capable of detecting earth-strength magnetic fieldsthrough a sensory process. In turn, the existence of this ability implies thepresence of specialized receptors which interact at the cellular level withweak magnetic fields in a fashion exceeding thermal noise. A simple calculationshows that magnetosomes moving in response to earth-strength ELF fields arecapable of opening trans-membrane ion channels, in a fashion similar to thosepredicted by ionic resonance models. Hence, the presence of trace levels of biogenicmagnetite in virtually all human tissues examined suggests that similarbiophysical processes may explain a variety of weak field ELF bioeffects.