Frank, are you aware of Edison's X-ray light bulb? It was an X-ray tube coated on the inside with calcium tungstate which fluoresces very brightly under X-rays. This was before anyone realised that X-rays are deadly.
Thomas Edison says with regard to this work: "When the X-ray came up, I made the first fluoroscope, using tungstate of calcium. I also found that this tungstate could be put into a vacuum chamber of glass and fused to the inner walls of the chamber; and if the X-ray electrodes were let into the glass chamber and a proper vacuum was attained, you could get a fluorescent lamp of several candle power. I began to make a number of these powerful lamps!
But while making these lamps, I soon found that the X-ray had affected poisonously my assistant, Mr. Dally, so that his hair fell out and his flesh commenced to ulcerate. I then concluded it would not do, and that it would not be a very popular kind of light; so I dropped it."