Re: Re[2]: Radon Question from Occ-Med-Env

[Bob Hearn <rah@america.net>]

There may be some efficacy to the use of charcoal cartridge breathers for
radon work.  Charcoal (especially at lowered temperatures) exhibits a
certain affinity for noble gases, characterized by dynamic absorption
coefficients corresponding to an effective delay in transit, a feature of
charcoal beds used in offgas treatment systems for BWR steam jet air ejector
exhaust to reduce xenon and krypton species prior to stack release.  The
effect appears to be greater for larger atomic number, and could be
significant at normal breathing rates for decay of radon to daughters which
are more effectively filtered.

Don't ask me for the corresponding data for radon, but I would be surprised
if these measurements had not been performed in conjunction with research on
sampling or treatment/remediation.

Bob Hearn
rah@america.net
770-993-3927


At 08:19 AM 7/2/96 -0500, you wrote:
>     The radon gas is the same concentration outside the mask as well as 
>     inside.  Any particulate daughters will be the same concentration on 
>     the inside as the outside due to continuous decay.  You may catch some 
>     particulates in the filters, but they would only possibly serve to 
>     give gamma dose to the face (immeasurable by far)?
>     
>     Glen
>
>
>______________________________ Reply Separator
_________________________________
>Subject: RE: Radon Question from Occ-Med-Env
>Author:  radsafe@romulus.ehs.uiuc.edu at INTERNET
>Date:    7/1/96 11:17 PM
>
>
>     
>The only protection that may be offered from radon (a gas) is an air 
>supplied respirator or a self contained breathing apparatus.  However, the 
>radon is not the exposure problem, the radon progeny are the culprits and 
>protection may be offered to some degree by a negative pressure respirator 
>with a HEPA filter cartridge.
> ----------
>From: radsafe
>To: Multiple recipients of list
>Subject: Radon Question from Occ-Med-Env 
>Date: Monday, July 01, 1996 8:06AM
>     
>     
>I copied this message from the occupational medicine BB. Perhaps RADSAFE 
>could offer an answer.
>*********
>Hello,
>     
>I am looking for informations about the effectiveness of protective masks 
>against radon and radon daugthers for workers exposed to concentrations up 
>to
>3000 Bq/m3 (81 Pico Curies/L).
>     
>Are there different ratios of protection ? 
>What are the prices ?
>     
>     
>Thanks in advance for your answers.
>     
>     
>Jean-Claude Dessau, md
>Medecin conseil
>Equipe de sante environnementale
>Direction regionale de la sante publique des Laurentides 
>185, rue Durand
>Saint-Jerome (Quebec)
>Canada J7Z 2V4
>     
>Tel: (514) 436-5669, # 242
>Fax: (514) 436-1761
>e-mail: jcdessau@InterLink.NET
>
>
>