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Radium dials

Radium dials are radioluminescent watch, clock and other instrument dials. In the early 1900s glow-in-the-dark clock and watch faces had the digits painted using paint containing Radium, the most common version created by the United States Radium Corporation was called, Undark.

Additional recommended knowledge



Radium dials were almost always painted by young women, who used to 'point' their brushes by licking and shaping the bristles prior to painting the fine lines and numbers on the dials. This practise, resulted in the ingestion of radium. The results of which resulted in serious jaw-bone degeneration and malignancy and other dental diseases reminiscent of Phossy jaw. The disease, radium-induced osteonecrosis, was recognised as an occupational disease in 1925.

By 1930 all dial painters stopped pointing their brushes by mouth. Stopping this practise drastically reduced the amount of radium ingested and therefore, the incidence of malignancy, to zero by 1950.

A factual account of events and the human effects was published in a book called The Radium Girls.

See also

  • Radium jaw
  • Radium Dial Company


  • Radium Girls: Women and Industrial health reform, 1910-1935.


This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Radium_dials". A list of authors is available in Wikipedia.
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