Radon

Uses

Radon has very few practical uses today, largely because its radioactivity makes it more of a hazard to manage than a resource to exploit. In the early-to-mid 20th century, small sealed capsules of radon gas, called radon seeds, were occasionally used in a form of radiotherapy to treat tumors, since the radiation it emits can damage cancerous tissue; this practice has almost entirely been replaced by safer, more precisely controlled radiation sources. Radon is also occasionally used in scientific research, for instance as a natural tracer that helps geologists study fault lines, groundwater movement, or soil permeability, since its concentration in air or water reflects underlying geological activity.

By far radon’s most significant modern relevance is as something to be monitored and reduced rather than used — building codes and health agencies in many countries recommend testing homes for radon and installing ventilation systems to keep indoor concentrations low.

History

Radon was discovered in 1900 by German physicist Friedrich Ernst Dorn, who noticed that samples of radium continually released a radioactive gas as part of their natural decay process. He referred to it as “radium emanation,” and other researchers around the same period identified similar emanations from thorium and actinium, which were later understood to be different isotopes of the same element. It eventually took the name radon to reflect its connection to radium and its place as a member of the noble gas group, once chemists confirmed that all these “emanations” were really the same chemical element.