Past & Current Uses of Radon

• Radon is a colorless, odorless, tasteless radioactive gas which can cause lung cancer. Steve Cole/Photodisc/Getty Images

  Radon forms from the natural radioactive decay of uranium. It constitutes one of the heaviest chemicals, and is gaseous at room temperature. Due to its density, it often accumulates in basements. It appears naturally, and at different concentrations depending on various geological factors. The Environmental Protection Agency says that radon acts as the second leading cause of lung cancer in the United States.

Treatment of Arthritis

• Some evidence--such as by 1999 German study published in the Oxford journal of rheumatology--suggests that low doses of radon exposure can trigger natural repair mechanisms in the body and help treat arthritis. This type of treatment is called "radiation hormesis," and it remains controversial. Still, many people suffering from arthritis, multiple sclerosis, depression and other ailments visit "radon spas" in converted mines. Radioactive water baths and radon spas have been used since even before the specific discovery of radon in 1900, based on anecdotal reports that miners noticed a reduction in arthritis symptoms.

Cancer Treatment

• Radon once saw use in radiation therapy to treat cancer, mostly from the 1940s to the 1960s. Since then, more modern radionuclides produced in particle accelerators and nuclear reactors have replaced radon. A form of "brachytherapy," which entailed a radiation source placed inside the body near the site of a tumor, constitutes one of the most common uses of radon for cancer treatment. It uses tiny radon-filled pellets made of glass, and then later gold, to destroy tumors. Gold replaced glass because it blocked alpha and beta radiation, which caused damage to healthy tissue, while allowing gamma radiation--the most useful in killing tumors--to escape.

Geology and Seismology

• Radon concentrations have been used to map fault lines, because concentrations usually run higher above faults. Scientists investigated radon as a possible predictor of earthquakes, but this method has never proved to be especially reliable. It may still hold some potential, however, and studies still continue.