A device adapted to fit within, or to be positioned adjacent to, a cellular handset or other personal communication device, for remedying the potentially harmful effect on humans or animal life of RF transmissions, and including an antenna responsive to the presence of RF radiation generated by the handset, signal analysis means for identifying the type of RF transmissions detected which is coupled to activate remedial signal generation means, which is arranged to provide a noise signal to a coil for providing an electromagnetic field in the vicinity of the handset, to disrupt the potentially harmful effects of the RF transmissions.