Radon in water by LSC (EPA Proposed Method)

[FIELDRW@aol.com]

Franz,

I think Paul was asking if anyone has experience specifically with APHA 
Standard Method
7500-Rn.  As you know, there are numerous parameters one can adjust when 
analyzing for waterborne radon using LSC.  My only concern with the proposed 
method is that the counting window is fairly narrow.  Even a small amount of 
quenching will give underestimtes of the true waterborne radon concentration. 
 While the window may be adequate for municipal water samples, I have 
analyzed thousand of private well-water samples and many of the samples 
contain high iron content which causes significant quenching.  I would be 
interested in others thoughts on the specific procedure Paul referred to.

Regards, 
Bill Field
College of Public Health
University of Iowa
Iowa City, Iowa
bill-field@uiowa.edu

In a message dated 1/7/00 5:08:28 PM Central Standard Time, schoenho@via.at 
writes:

<< EPA's proposed rule for Radon in Water specifies APHA Standard Method
 >7500-Rn, using liquid scintillation counting,  for the measurement.   Does
 >anyone on RADSAFE have any experience with this method?  
 
 Yes, I have extensive experience with measurement of Rn-222 (and Ra-226) by
 liquid scintillation spectrometry. We have measured several thousands of
 samples and also participated in (private) intercomparisons. We have used
 ultra low-level LS-counters (Quantulus) to achieve a high throughput, which
 was necessary due to the enormous number of samples to be measured within a
 short time and the short half-live of Rn-222. 
 
 For specific questions please contact me.
 
 Ragards,
 
 Franz
 
 
************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html