Microwave radiation cannot be carcinogenic or mutagenic as energy deposition is at energy levels well below that which case ionization. Any potential damage would actually have to be due to local heating, and with field intensities of milliwatts/cm2, local heating is much less than direct sunlight.
Most of the sub-6 GHz bands are not much different than current 4G/LTE technology or wifi. The biggest difference is that the higher frequencies in that range will not reach as far.
If you are going to worry, it's the millimeter wave (K and Ka band) 5G. These bands do not propagate far at all and will require loads of cells, including indoors. I don't see it having much of a role out in the country. With lots of cells, it give the carriers location tracking abilities not feasible today. If you walk up 5th Ave in NYC (provided there is reason to do so once 5G is deployed), a carrier could track your progress and what stores you likely walked into. If it's a big place like Macy's (provided it still exists), the carrier could track you moving from floor to floor.
I don't think the 5G crazies know much of this.
The tracking is already there anyway with GPS in your phone. That data’s being reported out constantly. No reason the provider couldn’t be grabbing that all day.
Just another reason why the phones and the providers should be separated like they are in Europe and most of the rest of the world. In places outside the US, you get your own phone. Then you connect it with whatever provider you want. They don’t get to load it up with their own software.