An EPA prescribed continuous recording monitor testing protocol, provides a written document containing a minimum of 48 hourly readings of radon gas along with temperature, relative humidity, and barometrical pressure, to ensure the integrity of the test. Radon gas and its decay product (finely divided metal, polonium) are radioactive and in sufficiently ingested amounts over period or time may cause lung cancer (second only to smoking). EPA recommends mitigation (specialized, but simple ventilation systems) be installed when the test average reads 4.0 (or greater) pico curies per liter.

What is Radon?
Radon is a gaseous radioactive element having the symbol Rn, the atomic number 86, an atomic weight of 222, a melting point of -71ºC, a boiling point of -62ºC, and (depending on the source, there are between 20 and 25 isotopes of radon - 20 cited in the chemical summary, 25 listed in the table of isotopes); it is an extremely toxic, colorless gas; it can be condensed to a transparent liquid and to an opaque, glowing solid; it is derived from the radioactive decay of radium and is used in cancer treatment, as a tracer in leak detection, and in radiography. (From the word radium, the substance from which it is derived.) Sources: Condensed Chemical Dictionary, and Handbook of Chemistry and Physics, 69th ed., CRC Press, Boca Raton, FL, 1988.

Where does Radon come from?
Sources of Radon come from the Earth and rock beneath home, and can also be in well water and building materials. It seeps into the house through the foundation of the house.

Studies Find Direct Evidence Linking Radon in Homes to Lung Cancer
(January 29, 2005 and March 16, 2005) Two studies show definitive evidence of an association between residential radon exposure and lung cancer. Two studies, a North American study and a European study, both combined data from several previous residential studies. These two studies go a step beyond earlier findings. They confirm the radon health risks predicted by occupational studies of underground miner's who breathed radon for a period of years. Early in the debate about radon-related risks, some researchers questioned whether occupational studies could be used to calculate risks from exposure to radon in the home environment. "These findings effectively end any doubts about the risks to Americans of having radon in their homes," said Tom Kelly, Director of EPA's Indoor Environments Division. "We know that radon is a carcinogen. This research confirms that breathing low levels of radon can lead to lung cancer."

For more information regarding Radon and its effects, please visit the Environmental Protection Agency's website on radon at www.epa.gov/radon/ or their frequently askes questions page at www.epa.gov/radon/radonqa1.html.