EMF Health-effects Research
Bioeffects induced by exposure to microwaves are mitigated by superposition of ELF noise. Litovitz TA, Penafiel LM, Farrel JM, Krause D, Meister R, Mullins JM Bioelectromagnetics 18(6):422-430, 1997 We have previously demonstrated that microwave fields, amplitude modulated (AM) by an extremely low-frequency (ELF) sine wave, can induce a nearly twofold enhancement in the activity of ornithine decarboxylase (ODC) in L929 cells at SAR levels of the order of 2.5 W/kg. Similar, although less pronounced, effects were also observed from exposure to a typical digital cellular phone test signal of the same power level, burst modulated at 50 Hz. We have also shown that ODC enhancement in L929 cells produced by exposure to ELF fields can be inhibited by superposition of ELF noise. In the present study, we explore the possibility that similar inhibition techniques can be used to suppress the microwave response. We concurrently exposed L929 cells to 60 Hz AM microwave fields or a 50 Hz burst-modulated DAMPS (Digital Advanced Mobile Phone System) digital cellular phone field at levels known to produce ODC enhancement, together with band-limited 30-100 Hz ELF noise with root mean square amplitude of up to 10 microT. All exposures were carried out for 8 h, which was previously found to yield the peak microwave response. In both cases, the ODC enhancement was found to decrease exponentially as a function of the noise root mean square amplitude. With 60 Hz AM microwaves, complete inhibition was obtained with noise levels at or above 2 microT. With the DAMPS digital cellular phone signal, complete inhibition occurred with noise levels at or above 5 microT. These results suggest a possible practical means to inhibit biological effects from exposure to both ELF and microwave fields |
Additional Web NotesThe above research deals with radio (microwave) frequencies, which have been 'modulated' (in this case, meaning almost 'pulsed', but actually varied in intensity more slowly) at 60 Hz (meaning sixty 'semi-pulses' of radio signal each second). Don't confuse this with 60Hz mains current, although the effects could come from the same cause. |