> Radiation is measured in gray, which is 1 J absorbed by 1 kg. I can't find the conversion between flux to absorbed dose. 5 gray is fatal. If even a fraction of that energy is absorbed, it would be fatal.
It's measured in a lot of different ways depending on the need, and the unit "sievert" is Gy times a conversion factor that depends on the kind of radiation (for equivalent dose) and which body parts (for effective dose): https://en.wikipedia.org/wiki/Sievert#Radiation_type_weighti...
But also, beta radiation (electrons) will be stopped by a thin sheet of tinfoil, while alpha radiation (helium-4 nuclei) by paper or the outer layer of dead skin on your body and therefore only matters if you eat a source of it, and a significant fraction of any gamma radiation you're exposed to will pass right through you without getting absorbed.
It's measured in a lot of different ways depending on the need, and the unit "sievert" is Gy times a conversion factor that depends on the kind of radiation (for equivalent dose) and which body parts (for effective dose): https://en.wikipedia.org/wiki/Sievert#Radiation_type_weighti...
But also, beta radiation (electrons) will be stopped by a thin sheet of tinfoil, while alpha radiation (helium-4 nuclei) by paper or the outer layer of dead skin on your body and therefore only matters if you eat a source of it, and a significant fraction of any gamma radiation you're exposed to will pass right through you without getting absorbed.