There has been some talk about 5G and health risks that range from hardly anything to frying your brain and controlling the population. This interesting article series is exploring the health risks posed by mmWave radiation onto humans.
Millimeter wave (mmWave) frequencies extend from 30 GHz to 300 GHz. From the literature, there can be three high-level concerns: thermal effects, ionizing effects, and electromagnetic (EM) effects.
The highest photon energy of a mm-wave photon is 1.2 meV that is 10,000 times less than what is needed to be ionizing. That still leaves thermal and EM concerns.
Most 5G systems use frequencies between 28 GHz and 80 GHz, the so-called FR2 frequency range. Many 5G systems also use the sub-6 GHz FR1 band.