Cob: Re: radon

[Mike Carter]

>I'm new to the list. I haven't built anything yet. But in considering a
>cob home or an earth home, do you have to take into consideration the
>radon levels in the soil? Do people test for this? It seems that a
>radioactive house may not be a great thing. Just wondering.
>
At one time I owned a home within walking distance of a superfund site where
a doctor, over decades, had used hollow needles filled with radium (the
precursor to radon) to treat cancer patients.  The waste from this operation
was scattered about the doctor's yard in suburban Philadelphia.  Somehow,
sand from his yard was sold to masons who used it to build the foundations
of over 100 homes in the immediate area.  These homes were built "leaky";
typically with stone foundations, wood framing, stucco siding and lathe and
plaster inside.  Some of the homes built with the contaminated sand had
levels of radiation inside that were high enough that they had to be
evacuated.

Gurus aside, I don't believe that one can make general statements about
homes made from any particular kind of wall system and how it relates to
radon.  The walls are only one part of the house system that affects air
exchange rate.  Basements, subfloors, the soil under the house, interior and
exterior finishes, number and detailing of windows and doors, vents, and
attic/roof system all impact the indoor air environment.  Radon tests are
simple and inexpensive.  There are also experts who can determine the rate
of air exchange within a structure.  If radon is a known problem in an area,
it would seem prudent to do the testing rather than risk your health.  I
would not want to live in a cob house made with contaminated sand.  Is cob
"proof" against radon?  I wouldn't bet my lungs on it without seeing a lot
of good data.

http://www.epa.gov/ttn/uatw/hlthef/radionuc.html for why this should concern
you.