AW: [ RadSafe ] Re: Residential radon risk

[Philippe Duport]

Please see "Determination de la fraction libre d'activité existant sous 
forme de RaA non attaché dans l'atmosphère d'une mine d'uranium" by A. 
Chapuis, A. Lopez, J. Fontan, Health Physics Vol. 25, pp. 59-65 (1973).   At 
that time, Health Physics accepted papers in French!  The fact that some 
papers were published in French or in languages other than English does not 
imply that the research has not been done and the information does not 
exist.

Chapuis et al report unattached fraction values from 1 or 2% close to an 
active stope, up to 15 to 20% without, or far enough from, active mining 
operations.  Miners do not spend all their time in close proximity to active 
mining operations.

I measured  unattached fraction values of the order of 30% in an isolated, 
inactive part of an underground uranium mine with forced ventilation (P. 
Duport, G. Madelaine, A. Renoux. Mesure de la fraction libre dans l'air 
d'une mine d'uranium laboratoire, Chemosphere 4(5):283-288, 1975) - sorry, 
another paper in French.

The unattached fraction is of course very sensitive to aerosol 
concentration, but it is a serious mistake to assume that it is always 
negligible in mines.

Philippe Duport


----- Original Message ----- 
From: <GELSG at aol.com>
To: <radsafe at radlab.nl>
Sent: Wednesday, June 01, 2005 1:35 AM
Subject: Re: AW: [ RadSafe ] Re: Residential radon risk


> Dr. Cohen:
>
> I generally agree with your work and conclusions on indoor radon. 
> However,
> the statement below troubles me.  In theory, in laboratory  conditions, 
> one
> can approach a UF of 1.0.  However, (and I have seen very  little data on 
> this
> point) I have never heard of real world UFs of more than  0.1, much less 
> 1.0.
> If you do have such data, I would like to see  it.  In my house, we always
> seem to have plenty of dust, even with the  electrostatic precipitator 
> running.
> I have always believed that, in the  real world of opening doors and 
> leaking
> windows and cooking and playing  children, there will always be plenty of
> "replacement dust" particles.  In  that case, I would take exception with 
> your
> conclusion about electrostatic  precipitators, and state that they would 
> be a very
> good means of reducing lung  exposure to radon daughters in homes that are
> not laboratory glove boxes.   As such, we should be actively encouraging, 
> not
> discouraging, their use.
>
> Gerald Gels
>
> _blc+ at pitt.edu_ (mailto:blc+ at pitt.edu)  wrote:
> "As an example, one
> can drastically reduce the WL by removing the dust (for example, with an
> electrostatic precipitator), but the newly formed radon daughters have
> no dust to attach to, so UF = 1.0, and the danger is not  reduced."
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