1. Feb 4, 2010

### chalk72

I have noticed that whenever the topic of radon comes up there are two probable reactions:
1. IQ quenching panic. Generally exhibited by members of the public at large.
2. Discussion quenching disgust. Most commonly displayed by devotees of the hard sciences. (Sometimes accompanied by hand-waving)

I would like to posit the existence of a third state: enlightening explanation. Specifically, I am in search of a derivation of the number of years required for a cumulative exposure of x milliSieverts of radiation in the presence of y picoCuries/liter of alpha radiation from radon. My own calculations have led me to conclude that for x = 100 it would take over 6,000 years for lungs of 2kg mass and 5 liter volume to reach this level given a Q of 20 and N of 0.12 (wikipedia) in the presence of 2 pCI/liter assumedly generated purely by alpha particles with an energy of 6.4MeV (highest decay energy for Radon products I could find). Alarmingly, or perhaps annoyingly, this disagrees hugely with data from the NCRP indicating an annual effective dose in the neighborhood of 1.7mSv for 1 pCi/liter, which would get you to 100mSV in only 29 years for a 2pCi/liter situation. If anyone (preferably not within groups 1 or 2 above) can shed some light on this disagreement, I would be most appreciative.

2. Feb 4, 2010

### bcrowell

Staff Emeritus
The estimate of 100mSV in 29 years sounds in the right ballpark to me. Natural background is on the order of 2 to 7 mSv/year, and I believe radon is of the same order of magnitude in houses that have a lot of radon.

Note that a wide variety of observations shows that LNT is totally wrong when applied to animal life at doses of less than about 10 mSv per *day*. People with radon in their basements are probably harvesting a slight health benefit, due to radiation hormesis. The benefit would be significant at the population level, but not worth worrying about at the individual level.

3. Feb 5, 2010

### Neil Craig

For centuries people have gone to spas to "take the waters" for their health & people are quite clear that it works whatever worries the authorities want to stir up. Such water comes from springs deep under the Earth & thus has a high concentration of radon & indeed uranium. This could not be so if the LNT theory were correct & highly unlikely to be true if there weren't a significant positive hormetic effect.