From a New York Times article titled "My Great-Great-Aunt Discovered Francium -- and It Killed Her" by Veronique Greenwood (2014):
MY GREAT-GREAT-AUNT DISCOVERED FRANCIUM. AND IT KILLED HER.
In her 1904 book “Investigations on Radioactive Substances,” Marie Curie wrote that radium had promise, too — diseased skin exposed to it later regrew in a healthy state. Radium’s curious ability to destroy tissue was being turned against cancer, with doctors sewing capsules of radium into the surgical wounds of cancer patients (including Henrietta Lacks, whose cells are used today in research). This enthusiasm for radioactivity was not confined to the doctor’s office. The element was in face creams, tonics, even candy. According to the Encyclopaedia Britannica article that Curie and her daughter wrote on radium in 1926, preliminary experiments suggested that radium could even improve the quality of soil.
And yet from the beginning, there were signs that radiation had sinister powers. In 1901, Henri Becquerel, the first person to observe radioactivity, reported strange burns he received from the vial of radium he carried in his waistcoat pocket. The burns appeared on the Curies’ hands as well. People who worked with X-rays at the beginning of the 20th century had a known tendency to lose their hair and develop burns on their skin and even cancer. In 1904, Clarence Dally, who was Thomas Edison’s X-ray assistant, died of cancer after having both his arms amputated to try to keep it from spreading. For all its anticipated promise in battling cancer, radiation was also clearly carcinogenic.
Perhaps the most tragic demonstration of this involved workers at the United States Radium Corporation factory in Orange, N.J., which in 1917 began hiring young women to paint watch faces with glow-in-the-dark radium paint. The workers were told that the paint was harmless and were encouraged to lick the paintbrushes to make them pointy enough to inscribe small numbers. In the years that followed, the women began to suffer ghoulish physical deterioration. Their jaws melted and ballooned into masses of tumors larger than fists, and cancers riddled their bodies. They developed anemia and necrosis. The sensational court case started — and won — by the dying Radium Girls, as they were called, is a landmark in the history of occupational health. It was settled in June 1928, four months before Marguerite Perey arrived at the Radium Institute to begin a 30-year career of heavy exposure to radiation.
The above article reflects the significant ignorance of the time to the deadly effects of ionizing radiation on biological tissues. Please note that hundreds of independent scientific studies confirm that the effects of non-ionizing radiation (the wireless type) are cumulative, increasing with exposure, and the damage to biological tissues is ultimately similar.