Handbook of Radon.
47. Medical uses of radium and radon.
The medical uses of radium and radon have a long history. Indeed, use of spa waters containing radon dates back to Roman times, long before radium was discovered by Marie Curie in 1898 and radon by Dorn in 1900.
Very soon after these discoveries, harmful effects such as skin burns and hair loss were observed amongst early experimenters, many of whom were to die as a result of their work. However, recognition of the carcinogenic properties of radiation was necessarily delayed for many years, because of the latency periods.
Deliberate use of radon and radium in medicine commenced in the early 1900s. It seemed logical to some people, including many doctors, that the power of these newly discovered 'scientific' substances could be turned against disorders within the body.
Nearly a century later and despite advances in knowledge, mines and spas in the USA, Europe, Japan and elsewhere and that contain high levels of radon are still open to members of the public. Breathing the air or bathing in the radon-rich water are believed to help cure arthritis as well as a range of other maladies.
Potential harm may be calculated according to whether the waters are drunk, and if so what they contain, and to what extent the spa or mine is ventilated so as to remove airborne radon.
Drinking radium or radon dissolved in water was popular in the 1920s and 1930s and was widely endorsed. The most radioactive of the commercially available waters were probably dangerous and many deaths may have resulted from their use.
However, ingestion of water containing radon is not a significant risk (see Section 35), and neither is bathing in spas. Likewise, radon water enemas are likely to be more unpleasant than harmful, unless perhaps heavily dosed with radium and administered frequently. This is most unlikely to occur today, but for a couple of decades many people exhibited a reckless enthusiasm for intake of natural radioactivity.
Long term exposure of radon facility attendants could still be a cause for concern but the radon-in-water concentrations would have to be exceptional before the resulting airborne level became significant. Direct emanation of radon from rock and soil in underground therapy centres is a more likely danger. In broad terms, the potential harm from smoking one cigarette is equal to that from one chest x-ray. Breathing a very high concentration of radon for only a few minutes would be equivalent, and is indicative of the risks to workers in spas.
Amongst the more considered uses of radon and radium have been within short-distance radiotherapy - as implants to help cure cancer. Here, it is the gamma emissions that are utilised, rather than the alpha particles that are of principal concern in radon-induced lung cancer.
The great advantage of these treatments was that they enabled concentration of radiation dose to the tumour with minimum dose to surrounding tissue, an especial concern in the early days of radiation therapy when equipment could not produce the finely collimated and directed beams that can be used nowadays. Nevertheless, the length of treatment was often determined by the need to limit dose to healthy tissue.
Man made isotopes of caesium and gold have largely replaced radium and radon in mainstream medicine. They are safer to prepare and use.