Prompted by the news that the last of the so-called Radium Girls had passed away at the age of 107, I thought it quite apt to take a look at the 1987 documentary Radium City (featured at the end of this article), which traces the story of Radium Dial Company in Ottawa, Illinois.

Women painting radium on watch dials for the proudly (and aptly) named Radium Dial company

Radium Dial moved to Ottawa from Chicago in 1922 and operated there until 1932 when it changed its name to Luminous Processes in reaction to a lawsuit. Luminous Processes remained in operation until 1977.

The women working in the factories were tasked with painting the numerals and other markings on the timepiece dials with a luminous paint comprising glue, water, and radium powder. The employees, now known as Radium Girls, were instructed to continuously reshape the hairs of the brushes they used by putting them in their mouths.

There was a similar factory owned by United States Radium in Orange, New Jersey – where Thomas Edison, who worked with fluoroscopy among other things, had his workshop.

This documentary goes into quite a bit of depth with regard to the injurious consequences of being overly exposed to radium, even for just a short amount of time. Extensive interviews with survivors and their families make this “black” chapter of American watchmaking a lesson filled with little light.

Radium Girls cartoon (courtesy www.emigennis.com)

Radium Girls cartoon (courtesy www.emigennis.com)

Radium mixed with zinc sulfide was used as a luminous substance on watch dials after 1902 (when Marie Curie gave William J. Hammer some radium samples) until the 1960s when it was replaced with tritium (mixed with zinc sulfide).

You can see the Radium City documentary about the Radium Girls story in the video above.

For more on luminous substance, see How We Realized Putting Radium in Everything Was Not the Answer.