Radium of radium Curie used the residues after extraction of uranium from pitchblende. The uranium had been extracted by dissolution in sulfuric acid leaving radium sulfate, which is similar to barium sulfate but even less soluble in the residues. The residues also contained rather substantial amounts of barium sulfate which thus acted as a carrier for the radium sulfate. The first steps of the radium extraction process involved boiling with sodium hydroxide followed by hydrochloric acid treatment to remove as much as possible of other compounds. The remaining residue was then treated with sodium carbonate to convert the barium sulfate into
Radium Girls was about a penny and a half per dial (). The brushes would lose shape after a few strokes, so the U.S. Radium supervisors encouraged their workers to point the brushes with their lips ("lip, dip, paint"), or use their tongues to keep them sharp. Because the true nature of the radium had been kept from them, the Radium Girls painted their nails, teeth, and faces for fun with the deadly paint produced at the factory. Many of the workers became sick; it is unknown how many died from exposure to radiation. Many of the women later began to suffer