'The Radium Girls were a group of female factory workers who contracted radiation poisoning from painting watch dials with glow-in-the-dark paint at the United States Radium factory in Orange, New Jersey around 1917. The women, who had been told the paint was harmless, ingested deadly amounts of radium by licking their paintbrushes to sharpen them; some also painted their fingernails with the glowing substance.

Five of the women challenged their employer in a court case that established the right of individual workers who contract occupational diseases to sue their employers.'

Read more: Hidden History: The Radium Girls