I am sorry for your friend's psychosomatic illness. Cell towers, wifi, microwaves, wireless phones, etc. all operate at frequencies below infrared, not above ultraviolet. There are "regulation and health risks" for parts of the spectrum above ultraviolet because that contains X-rays, gamma rays, and other forms of nasty ionizing radiation. Things below ultraviolet are non-ionizing and will do no more than heat you up... very very slightly too, unless you're standing in front of a microwave transmitter, thanks to the inverse square law.