I think you don’t understand what i am saying at all. A Sv takes that into account. Neutrons for example give a much higher number since they do more damage. Alpha radiation *outside* the body give you zero does as it does not penetrate the dead skin. All elements have a half life in the body and don’y stay there forever and typically far far less than a half life. I worked around radioactive isotopes. It not inaccurate.
Did you even watch the video I posted?
