To explain something, because this keeps going around, they're conflating ionizing EM radiation with electromagnetic radiation in general. Electromagnetic radiation of the kind emitted by cellphones is basically harmless. You'd have to be outputting a significant amount of energy for it to have any harm because the photons emitted don't have enough energy to actually damage physical matter. The dangerous kind (ionizing em radiation) is only UV and above. Radiowaves, microwaves, infrared and visible light are all pretty harmless unless you're outputting enough to literally cook food.

Here's an image showing where the different wavelengths are: