More About Radon

• Radon was discovered in 1900 by Frederich Dorn, who called it radium emanation. Radon gas has been known by its current name since 1923.

• Stanley Watras brought the radon issue to public attention in 1984. Mr Watras, a construction worker, entered Limmerick Nuclear Power Plant in Pottstown, Pennsylvania. There were no radioactive materials yet at the plant, but he set off the radiation monitors because of radon and radon progeny clinging to his clothing and skin. With Watras's urging, they decided to test his home for radiation contamination and found high levels of radon.

• The Watras case prompted a regional testing program and this information led the US EPA to launch advertising campaigns and, in 1986, pass the Indoor Air Quality Research Act. This Act prompted states to create their own radon programs.