In addition, demodulation of these signals would lead to the presence of electric
fields at 217 or 17.5 Hz and their harmonics, as well as fields at frequencies relating
to the digital stream (tens of kHz). Now, the ICNIRP public exposure guidelines for
low-frequency electric fields (4–100 Hz) of 2 mV/m (for tissue of resistivity 1 Ωm) is
less than the corresponding guideline at 1 GHz of around 100 V/m. Accordingly, even
weak demodulation of mobile phone signals at these fields produces low-frequency
electric fields above the protection guidelines