Thanks for the links. Back in physics grad school we used to calculate (as homeworks) cross sections for such interactions, so I knew right off that comparing soft X ray photons of the scanners to hard gamma ray photons (such as the cited 2 minute flight equivalence TSA claim) is comparing apples and oranges, as explained earlier. The cross section decreases with third power of photon energy (see Klein-Nishina formula, the main term P^2 * P ~ P^3, where P ~ 1/E_gamma; E_gamma is the photon energy), so a 1000 times greater energy of cosmic ray gamma photon vs soft X-ray photon will mean billion times smaller cross section for cosmic ray gamma. Since either photon will damage/ionize a molecule upon inelastic scattering (they are both well above ionization threshold), the molecular damage risk of equivalent energy soft X-rays from scanners are many orders of magnitude greater than those of cosmic gamma rays with the same total energy.
There’s a link right above your comment to me about this as well.
I’m a science-tard but I still limp along trying to get a tiny grasp of it all.