eli5 How come if highly radioactive radium was on watches that the wearers didn’t succumb to radiation poisoning at the wrist?

Question

eli5 How come if highly radioactive radium was on watches that the wearers didn’t succumb to radiation poisoning at the wrist?

In: 186

Answer 1

Radium itself doesn’t glow. The watch dials were done with luminous paint containing only enough radium to get the paint to luminesce due to the gamma radiation emitted by the radium.