The iron cage protein ferritin is an obvious candidate to study the effects of radiofrequency magnetic fields at the molecular scale, because it has the highest net magnetic moment of all proteins and plays an essential biological role, being present in organisms from bacteria to humans. Ferritin oxidizes the harmful Fe2+ ions and stores them in the cavity, forming a ferrihydrite nanoparticle with up to 4,500 iron ions.
|Frequency||250 kHz–2 MHz|
|Exposure duration||up to 9 h|
|magnetic flux density||15 µT||minimum||calculated||-||-|
|magnetic flux density||30 µT||-||calculated||-||-|
|magnetic flux density||45 µT||-||calculated||-||-|
|magnetic flux density||60 µT||maximum||calculated||-||-|
|electric field strength||0.1 V/m||-||measured||-||at 250 kHz|
|electric field strength||0.4 V/m||-||measured||-||at 2 MHz|
The data show that the rates of iron chelation with ferrozine are reduced by up to a factor of three in proteins previously exposed to radiofrequency magnetic fields of 1 MHz and 30 µT for several hours. The effect is non-thermal and depends on the frequency-amplitude product of the magnetic field.