Radium is a radioactive element discovered by Marie Curie in 1898, which initiated a bit of a radium craze until it was better understood to be very dangerous. Radium was used in the luminescent paint that the women handled every day in the factories, even ingesting the paint when they used their lips to contour the brushes.

Sadly, by the 1930s, most of the Radium Girls had died from cancers and bone degeneration, and their employer, the United States Radium Corporation, refused to take responsibility for their demise. This led to a rash of lawsuits that changed the way we treat workers, creating watchdog groups that have made workplaces safer all around the world.