Effects of extremely-low-frequency magnetic fields on biological magnetite.

Adair [Bioelectromagnetics 14:1-4, 1993] writes that "the effects of 60 Hz magnetic fields of 5 microT (50 mG) or less on biological structures holding magnetite (Fe3O4) are shown to be much smaller than those from thermal agitation; hence such interactions cannot be expected to be biologically significant." This conclusion is questioned, because it appears to be based on a model that probably has very limited validity for pertinent biological systems. Furthermore, biologically plausible parameters can be selected to show that even this particular model does not exclude biologically significant effects of 60 Hz magnetic fields below 5 microT. Reported experimental results indicate effects in mammals of 50 Hz fields at the 1 microT level.