[Strawbale] Radiating earth

[Dave Howorth]

On Thu, 2012-06-21 at 14:11 -0600, Derek Roff wrote:
> Someone asked me off-list how you test for radon.  Testing must be
> done in a laboratory with very specialized equipment.

Derek, your posts are very informative but I fear they rather fall wide
of the mark. The subject that Sara raised is about some German research,
published last year, specifically about Radon 224 generated by Thorium
232 decay, and thoron's decay product 212Pb.

As you say, radon in buildings is normally measured by a process that
takes some considerable time and that therefore does not measure short
half-life products. The authors have established a procedure to measure
these products and tested it in a laboratory test building and in real
vernacular buildings in India and China. The results apparently show a
significant increase over levels measured in the conventional way.

This in turn implies that conventional defences against radon gas
entering a building will have negligible effect on decay products
generated within the fabric of the building itself. This has long been
recognized with regard to Scottish buildings built from granite.

So far, it appears to be good science, contributing to our knowledge of
the built environment. It does not change my plans to plaster the inside
of our house with clay plaster. But the research has been reported in a
somewhat sensationalist fashion in the German press and consequently a
fraction of the public has become concerned. Unfortunately, this
includes some of Sara's clients.

So what I believe is desirable is a considered, specific response to
this research, putting it in the context of modern western-style earth
building techniques, and highlighting any best practice implications.

The first step is to read the original research:
http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0668.2010.00697.x/abstract

Sara, this wikipedia article puts things into some kind of context:
http://en.wikipedia.org/wiki/Background_radiation

Regards, Dave