Radium

Uses

Radium’s most well-known historical use — mixed into luminous paint for watch faces, clock dials, and aircraft instruments so they would glow in the dark — has been completely discontinued since the mid-20th century, once it became clear how dangerous ingesting or inhaling radium particles could be, particularly for the factory workers who painted the dials by hand. Safer luminescent materials replaced it entirely for that purpose decades ago.

Radium does still have a narrow, tightly controlled medical use today: a radioactive isotope called radium-223 is used in an approved treatment for certain prostate cancers that have spread to the bones, where its radiation targets the affected bone tissue directly. Outside of this specific medical application and ongoing scientific research, radium has essentially no other current use, given how hazardous it is to handle.

History

Radium was discovered in 1898 by Marie and Pierre Curie, working in Paris, as they investigated the intense radioactivity coming from uranium ore that couldn’t be explained by its uranium content alone. Painstakingly processing tons of pitchblende ore, they isolated tiny amounts of a new, strongly radioactive element and named it radium, from the Latin word for “ray.” The discovery, made in the same year as their discovery of polonium, was a major milestone in early radioactivity research, though it would take decades longer for scientists and the public to fully grasp how dangerous the element the Curies had found really was.