• Radon was officially discovered in 1900 by Friedrich Ernst Dorn who named it "Radium Emanation"
• In 1910, radon was formally identified as a new element in the periodic table, a radioactive noble gas , Rn 222.
• Radon comes from the natural decomposition of uranium and radium present in the earth's crust.
• As radon decomposes, it forms “ Radon Decomposition Products” (RDPs) including Polonium 218 and Lead 214, solid elements.
• Radon is a heavy gas that will tend to accumulate in the basement.

In the open air, radon is present in small quantities, approximately 10 bq/m3, so it does not represent a danger. However, in our homes, it can accumulate in significant quantities in the basement and represent a significant danger to the health of the occupants.