Exposure of human lymphocytes to sweeping-frequency ELF MF

Whereas most of the research on possible bioeffects of extremely low frequency magnetic fields (ELF MF) on blood cells has been performed at 50/60 Hz regardless of background fields, here, we exposed human lymphocytes to sweeping-frequency ELF MF in a different range, defined by the DC background field of our incubator and the corresponding ion-cyclotron frequencies. Umbilical cord blood lymphocytes (UCBL) were isolated and exposed for 48 h to an ELF MF (sinusoidal, frequency sweeping 3-26 Hz) with 6 different amplitudes between 6 µT and 24 µT, utilizing an oblong coil. DNA double-strand breaks (DSB) were assessed by enumeration of γH2AX, 53BP1 and γH2AX/53BP1 co-localized DNA repair foci. Percentage of viable, early apoptotic (EA), and late apoptotic/necrotic (LAN) cells were determined. No statistically significant effects were seen for DNA repair foci or apoptosis induction after a 48-h exposure of UCBL with frequency-sweeping ELF MF. More than 2-fold decrease (p = .064) of γH2AX foci level was detected for 8 µT amplitude when compared to controls. For the same field intensity, a decrease in viable cells was suggested by the data. Our findings suggest that at least part of the exposure could have had a preventive/blocking effect on DNA DSB formation suggesting the possibility of using sweeping-frequency ELF MF as a protective measure against genotoxic agents. It is desirable to continue testing variations of the exposure utilized in this work, in order to search for the most biologically effective frequencies/patterns of exposure.