http://www.damninteresting.com/undark-and-the-radium-girls/Undark and the Radium GirlsIn 1922, a bank teller named Grace Fryer became concerned when her teeth began to loosen and fall out for no discernible reason. Her troubles were compounded when her jaw became swollen and inflamed, so she sought the assistance of a doctor in diagnosing the inexplicable symptoms. Using a primitive X-ray machine, the physician discovered serious bone decay, the likes of which he had never seen. Her jawbone was honeycombed with small holes, in a random pattern reminiscent of moth-eaten fabric.
As a series of doctors attempted to solve Grace’s mysterious ailment, similar cases began to appear throughout her hometown of New Jersey. One dentist in particular took notice of the unusually high number of deteriorated jawbones among local women, and it took very little investigation to discover a common thread; all of the women had been employed by the same watch-painting factory at one time or another.
In 1902, twenty years prior to Grace’s mysterious ailment, inventor William J. Hammer left Paris with a curious souvenir. The famous scientists Pierre and Marie Curie had provided him with some samples of their radium salt crystals. Radioactivity was somewhat new to science, so its properties and dangers were not well understood; but the radium’s slight blue-green glow and natural warmth indicated that it was clearly a fascinating material. Hammer went on to combine his radium salt with glue and a compound called zinc sulfide which glowed in the presence of radiation. The result was glow-in-the-dark paint.
Hammer’s recipe was used by the US Radium Corporation during the First World War to produce Undark, a high-tech paint which allowed America’s infantrymen to read their wristwatches and instrument panels at night. They also marketed the pigment for non-military products such as house numbers, pistol sights, light switch plates, and glowing eyes for toy dolls. By this time the dangers of radium were better understood, but US Radium assured the public that their paint used the radioactive element in “such minute quantities that it is absolutely harmless.” While this was true of the products themselves, the amount of radium present in the dial-painting factory was much more dangerous, unbeknownst to the workers there.
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