From about 1917-1926 some young women who worked in watch/clock factories would later die a miserable death due to radiation poisoning. Their job involved painting clock and watch dials with radium paint. To get better detail they would frequently moisten the tips of the delicate paint brushes in their mouths. In addition many would take paint home and decorate their bodies with it to amuse their boyfriends, They became collectively known as the radium girls.
The dangers with radiation really weren't understood - even the eminent researcher Madame Curie would die from radiation induced leukemia.