Re: Pb-210 on air filters

["J. L. Alvarez" <jalvarez@auxier.com>]

NCRP Report # 94, page 102 states the concentration in air of Pb-210 is 20 fCi/m3
and Po-210 is 2 fCi/m3.  My experience is that these two concentrations are good
predictors for just about everywhere in the US.

brian.keele@swec.com wrote:

> Does anybody have any information relating to the amount of Pb-210, or other
> natural ambient isotopes, that could realistically accumulate on an air filter
> in
> an outdoor environment and present an interference in a gross alpha measurement?
> The filters are held for 14 days before a gross alpha counting to allow short
> half-life radon/thoron daughters to decay.  We have a thorium site.  I suspect a
> large proportion of the observed counts from our perimeter stations may be from
> Pb-210.
>
> Thank-you,
> Brian Keele
>
> ************************************************************************
> The RADSAFE Frequently Asked Questions list, archives and subscription
> information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html
begin:vcard 
n:Alvarez;Joseph L.
tel;fax:865-675-3677
tel;work:865-675-3669
x-mozilla-html:FALSE
org:Auxier & Associates, Inc.
adr:;;9821 Cogdill Rd., Suite 1;Knoxville;TN;37932;
version:2.1
email;internet:jalvarez@auxier.com
fn:Joseph L. Alvarez
end:vcard