HYPOTHETICAL BIOPHYSICAL MECHANISMS FOR THE ACTION OF WEAK LOW-FREQUENCY ELECTROMAGNETIC-FIELDS AT THE CELLULAR-LEVEL

Power-line frequency electric fields of 1 mV.m(-1) in the body can be induced by external electric fields of 10 kV.m(-1) and by magnetic fie lds of 50 mu T through the Faraday effect. Constraints from physical p rinciples show that such internal fields are unlikely to generate any biological effects and fields less than 0.1mV.m(-1) must be ineffectiv e. Moderately strong power line frequency magnetic fields may affect b iology through the direct interaction of the fields with the magnetic moments of ferrimagnetic materials in the body and through effects on radical pair recombination as a consequence of the interaction of the fields with electron magnetic moments. However, magnetic fields smalle r than 50 mu T (500 mG) are unlikely to affect biology, and fields les s than 5 mu T cannot do so. Ion Cyclotron Resonance and Ion Parametric Resonance models of biological effects of the interaction of power-li ne frequency magnetic fields with the magnetic moments of ions are not in accord with fundamental physical principles.