Radon is a tricky thing to categorize. Whether it’s testing the invisible, odorless gas or determining its risk, radon as an intermediary step in the radioactive decay chain, can be exceedingly hard to pin down. Even historically things are murky. The discovery of radon is attributed to multiple people, depending on who you ask. Google search results will attribute radon to Marie Curie, Friedrich Ernst Dorn or, as I would attribute it based on date and isotope, Ernest Rutherford and Robert B. Owens. The turn of the century was an exciting and busy time for radioactivity and for science!

Radon Related Dates and Discoveries:

• Paracelsus - 1530
  Described the Scheneeburger Lung Disease or “Mala Metallorum” affecting miners in the Joachimsthal region in Saxony/Germany region, assumed to be from inhaling the ore dust containing various metals at the mines.

• Georgius Agricola - 1556
  Recommended ventilation in mine shafts to treat miner’s illnesses Paracelsus had described.

• Henri Bequerel - 1896
  Discovered radioactivity while researching phosphorescence in uranium salts.

• Marie and Pierre Curie - 1899
  1898 Marie and her husband Pierre were in the midst of their groundbreaking work on radioactivity, a term which they coined, to describe the change of state from one element to another.

• Ernest Rutherford and Robert B. Owens - 1899
  Detected a radioactive gas released from the breakdown of thorium (radon 220) and called the gas “emanation”. Rutherford determined it was possible to condense radon into a liquid.

• Friedrich Ernst Dorn - 1900
  In experiments on radium, found that a gas was accumulating inside ampoules of radium (radon 222) which he coined “radium emanation”.

• Julius Elster and Hans Friedrich Geitel - 1901
  Discovered radioactivity through ionization in air and developed  the first radon measurement devices to prove it, confirming an earlier hypothesis from 1899 when they suggested that radioactivity may be due to the decaying of atoms. Below, Elster and Geitel with their photometer, Fricke, R. G. A.: J. Elster & H. Geitel – Jugendfreunde, Gymnasiallehrer, Wissenschaftler aus Passion, Döring Druck und Verlag, Braunschweig, 1992.

• Ernest Rutherford and Harriet Brooks - 1904
  Determined that the emanations Dorn had discovered were radioactive. 

• William Ramsay and Robert Whytlaw - Gray - 1908
  Determined radon to be the heaviest gas yet known. 

• First radon related illnesses conclusively proven - Early 20th Century
  Radium materials had developed into a medical wonder in its ability to treat cancers and illnesses. Long term these therapies were proving to be more costly than previously imagined.

• William F. Bale - 1951
  Suggested a link between radon concentration in air to lung cancer development.

  
  
  The science and hisotry is still developing and with it our understanding. For further information about radon research and developments check out our "Publications", "Current Guidelines" and "Radon In the News".