This post will be of interest to absolutely no one, except on the off chance you're curious about how we know that "5G radio waves" don't cause cancer, COVID-19, extra-limbs, or spider-like super powers.
There is going to be some straight-forward arithmetic (with very large and very small numbers), but I'll do the arithmetic for you so you can follow along without a calculator.
A quick refresher on the electromagnetic (i.e. E-M) spectrum: radio waves, infrared light, visible light, ultra-violet, x-rays, and gamma rays are all a part of the same electromagnetic spectrum. They all come in "quanta" of the E-M field that permeates the universe, and the usual name we give to one of those "quanta" is "photon". The photons of radio waves, visible light, ultraviolet and all the other regions of the E-M spectrum are fundamentally identical to each other save for one property: their frequency (or stated a different way, they differ only by wavelength, which is inversely proportional to frequency).
Unlike ordinary matter, the energy (measured in joules) of a photon is related to one thing only: its frequency. The equation to derive a photon's energy from its frequency is super simple: E = hf, where E is the energy (in joules), f is the frequency (in hertz, or "hz"), and h is the physical constant known as "Planck's Constant". If you read a physics text, the variable used for frequency will usually be the Greek letter 'nu', but we're going to stick to using 'f' because I don't know how to type a 'nu' 🙂
Planck's Constant is very small, with a value of 6.62607004 x 10^-34 joules/hz. (The "10^-34" means the fraction "1 / 1-followed-by-34-zeroes")
A quick review of high-school chemistry: all chemistry happens via ionization, the process of moving electrons from the shell of one atom to the shell of another. The energy required to ionize an atom (and thus, to cause chemical changes) varies from element to element and from isotope to isotope. The element with the lowest ionization energy (that is, the atom that is the absolute easiest to induce to participate in a chemical reaction) is isotope 136 of the element Cesium. All other atoms require more energy to ionize (i.e., are harder to persuade to participate in a chemical reaction) than Cesium-136 is, but our example is going to stick to Cesium-136 for the sake of demonstration.
Keep in mind that in order to damage cells (including DNA), either chemical changes or nuclear changes must occur in an atom. Nuclear changes require many, many more orders of magnitude of energy than we will be talking about and will be left out of this discussion. If a radio wave is going to change the molecular makeup of a cell, it will have to be chemical ionization.
Back to that "easy to ionize" Cesium: the energy required to ionize (and therefore cause chemical changes with) an atom of Cesium-136 is 6.24 x 10^-19 joules.
The highest frequency used in 5G radio is about 30 GHz. (That's 30,000,000,000 hz). To compute the energy delivered by a 5G radio photon (remember E = hf), we multiply by Planck's Constant. Doing the arithmetic, we compute the energy of a 5G radio photon to be 1.99 x 10^-23 joules.
To sum up:
Energy required to ionize the easiest atom to ionize = 6.24 x 10^-19 joules
Energy delivered from a 5G radio (i.e, 30GHz) photon = 1.99 x 10^-23 joules
Stated another way (and taking the ratio of those two values), a 5G radio photon has only 1/31,385th of the energy required to ionize the easiest atom to ionize.
If your curious, a little arithmetic shows that the minimum E-M frequency that can ionize any atom at all is 942,000 GHz. A little more arithmetic converts that to a wavelength of about 320nm, which is ultraviolet light.
As you can see from the arithmetic above, radio-frequency photons carry only a very minuscule fraction of the energy that visible light does. If RF photons were capable of causing chemical changes in our cells or in our DNA, then sitting under an ordinary light-bulb would effectively turn us into a puddle of goo.
There's one caveat here: we've been talking about energy, not power. The received power of cell-tower radio waves is measured in nanowatts (that's a billionth of a watt). If you were able to stand close enough to a powerful enough transmitter (and I mean, right on top of it), you could absorb enough power to cause chemical changes (and burns!) simply by raising the physical temperature of your body rapidly. (This is how a microwave oven works). But to re-iterate, I promise that as we walk around in the ordinary world, neither the radio waves from your wi-fi or radio waves from cell-towers or the radio waves from your favorite DJ reach you with anywhere near enough power to cause any measurable heating of your body.