I am reading a fascinating book on the development of the Atomic bombs and the development of related radioactive materials.
I stumbled across this tragic story of women who worked painting the first luminescent paints onto watches. As they used their mouths to sharpen their brushes before applying the paints, they began to suffer horrible cancers in their mouth. They were known as the "Radium Girls"
i did a bit more research and found this link. Don't know if this has been discussed before.
Undark and the Radium Girls • Damn Interesting