All you need to know to understand 5G

https://www.youtube.com/watch?v=FBsP-bmDLOo

All wireless technology uses electromagnetic radiation to encode and send information. The new millimeter waves are in the high-frequency part of microwaves. The waves are quantized, meaning they are small packs of energy called photons. 

The ENERGY of the radiation is proportional to the FREQUENCY (GHz) of radiation. A high frequency means a short wavelength thus large energy output PER PHOTON. Small frequency means a long wavelength thus a small energy output PER PHOTON (GHz). To DAMAGE A MOLECULE, what matters is the energy output per individual photon in the radiation, which is the frequency of the radiation that can break the bonds of the atoms in a molecule. Therefore, a large amount (frequency above ultraviolet light) of energy PER PHOTON in the radiation is necessary to damage a molecule. 

All the radiation of energy for wireless networks including 5G, uses a frequency that is way below infrared, and infrared is below ultraviolet and may only warm tissue. Unfortunately, tissue can be harmed just by warming it. The amount of warmth is determined by the number of photons (power aka, watts) and the fraction that was absorbed by the tissue. 

Wireless routers typically use tens of thousands of times less wattage than a microwave oven. Microwave 400-100 watts, wireless 100 milliwatts while both have approx 2 GHz. Also, routers radiate into space not a closed cavity, thus the power reduces with distance. However, power (wattage) alone does not tell you how much energy is absorbed by the tissue. 

5G uses electromagnetic radiation in 3 bands of the spectrum.  Low; mid; high. The frequency in the High band has primarily been unused because it does not transmit well in long-range as anything can block the waves.  Therefore, use small cells for the millimeter waves at distances of about 100 meters or 109 yards apart.  The small cells communicate short-range with macro cells. The macro cells communicate long-range use low and mid-band at higher power thus increasing exposure to millimeter waves, which cell phones generally don't use.  To date, there are no reliable studies concerning LONG TERM EXPOSURE from millimeter wave exposure.  The waves don't penetrate the body but they do warm the skin and irritate the eyes. So how much power is too much no one knows.