All electromagnetic radiation (EMR) with frequencies below higher ultraviolet (low ultra violet, visible light, radio waves) are non-ionizing. High ultra-violet, gamma waves and x-rays are ionizing.
The typical house has quite a few non-ionizing radiation emitters. TVs, wi-fi routers, cell phones, cordless phones, microwave ovens. EMR is all around us at all times.
The only thing about cell and cordless phones is that we use them by putting them right up against our head. The closer a transmitter is to the brain, the more effect it would have, assuming there is some type of effect.
I understand the physics of it as well, but when I drive home in front of a car, and the same car goes nearly all the way with me...and the cell phone doesn’t budge from their head or their mouth stop moving in a solid hour, it does make me wonder.
Of course, it might be Darwin at work too.