Explanation: https://en.wikipedia.org/wiki/Radium_Girls
The Radium Girls were female factory workers who contracted radiation poisoning from painting radium dials – watch dials and hands with self-luminous paint. The incidents occurred at three factories in the United States: one in Orange, New Jersey, beginning around 1917; one in Ottawa, Illinois, beginning in the early 1920s; and one in Waterbury, Connecticut, also in the 1920s.