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

[Keith Brown <KDB1@nrc.gov>]

>>>>>>>>>>>>>>>
     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

<<<<<<<<<<<<<<<

This is not necessarily true that any particulate daughters will be at the
same concentration on the inside as on the outside of the mask.  The
radon daughters, being charged (the outgoing alpha and sudden change
in nuclear charge tend to disrupt the electrons a bit) have an affinity for
dust particles.  Keeping out dust with attached radon daughters would
reduce dose.  In fact, cleaning air has been used as a method of reducing
radon dose in mines (per some articles in Health Physics some years ago.

On the other hand, many ordinary dust masks do not do a particularly
good job of eliminating dust (given my allergies, I can attest to this).  So
while a dust mask wouldn't hurt, I don't think one should count on it to
dramatically reduce dose.

Keith Brown
kdb1@nrc.gov