Radium dial painters

The Radium Girls were female factory workers who contracted radiation poisoning from painting watch dials with self-luminous paint. Painting was done by women at three different sites in the United States, and the term now applies to the women working at the facilities. The first, United States Radium factory in Orange, New Jersey, beginning around 1917, at Ottawa, Illinois, beginning in the early 1920s, and a third facility in Waterbury, Connecticut.

The women in each facility had been told the paint was harmless, and subsequently ingested deadly amounts of radium after being instructed to "point" their brushes on their lips in order to give them a fine point; some also painted their fingernails, face and teeth with the glowing substance. The women were instructed to point their brushes because using rags, or a water rinse, caused them to waste too much time and waste too much of the material made from powdered radium, gum arabic and water.

Five of the women in New Jersey challenged their employer in a case over the right of individual workers who contract occupational diseases to sue their employers under New Jersey's occupational injuries law, which at the time had a two-year statute of limitations, but settled out of court. Five women in Illinois who were employees of the Radiant Dial Company (which was unaffiliated with the United States Radium Corporation) sued their employer under Illinois law, winning damages in 1938.

From 1917 to 1926, U.S. Radium Corporation, originally called the Radium Luminous Material Corporation, was engaged in the extraction and purification of radium from carnotite ore to produce luminous paints, which were marketed under the brand name "Undark". The ore was mined from the Paradox Valley in Colorado and other "Undark mines" in Utah. As a defense contractor, U.S. Radium was a major supplier of radioluminescent watches to the military. Their plant in Orange, New Jersey, employed more than a hundred workers, mainly women, to paint radium-lit watch faces and instruments, misleading them that it was safe.

...
Wikipedia