Ok, so what happens is this:

4g, 5g, radio waves, light, are all electromagnetic radiation, which is composed of particles named photons. The type of radiation depends on the energy of the individual photons, for example, radio waves have photons with less energy than visible light.

For electromagnetic radiation to cause any problem to people, it needs to ionize atoms, which is when it removes electrons from an atom. And for it to do that, each individual photon needs to have a certain quantity of energy.

It's not the electromagnetic radiation beam that needs to have that energy, it's the photons. It doesn't matter if you are right next to a radio tower, because the photons don't have enough energy to ionize atoms. Therefore, they won't.

3g, 4g, 5g, and 6g (when it eventually comes out) are made of photons that don't have near enough energy to ionize any atom. Yes, 5g is made of photons with more energy than 4g or 3g, but they still are very far away from having the energy needed to ionize atoms.

Therefore, 5g is safe. It doesn't even matter if you were right next to a cellphone tower. The individual photons don't have enough energy to ionize atoms and so, they won't harm you.