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

[David Abbott <abbott@washops.llnl.gov>]

Consider what happens when actinon gas, Rn-219, gets inhaled through a HEPA
filtered air purifying respirator.  The 4 second half life makes things real
interesting.  Like 2,000,000 dpm alpha nosewipes.   The short half life
should cause a combination HEPA/charcoal filter to have some effectiveness.
Just a reminder, in the DOE world there are no air purifying respirators
approved for use against radioactive gases.  

David Abbott
Lawrence Livermore National Laboratory
abbott@washops.llnl.gov

At 12:51 PM 7/2/96 -0500, Ccja@aol.com wrote:
>I haven't followed this thread closely, but I think that what he means is
>that it would only take about three minutes for the first alpha-emitting
>daughter (Po-218) to be at 50% equilibrium with the radon inside the mask,
>assuming that none of it is returned outside the mask (clearly not the case).
>Is it taken for granted that we're talking only about "radon" as Rn-222, with
>a 4 day 1/2life, here? What about thoron, Rn220, with a 55 second 1/2life?
>