Radon in urine Part 2

["Moroney, Roger W" <WRMoroe@MKG.com>]

I have received many helpful replies to my original posting regarding
the radon progeny in an urine sample. Based on them, I counted an empty
vial from the same box of vials and did not find anything. I also
counted another urine sample from the subject this past Fri which also
came up clean.

The vials were recently received in our lab. There were stored in the
original plastic wrapped container and had been opened about 5 days
before the first problem. The screw caps are in a separate bag. One
reply discussed static electricity, plastic vials and radon progeny.
This may be a possible solution.

Several respondents inquired as to subtraction of environmental
background from samples. Yes there was. I have not seen much of a
problem in the past (which is not all that long) with radon progeny in
either our gamma spect results or in the background counts. Certainly
nothing like the recent urine sample. It seemed to me that it was not
actually from the subject but having a lack of knowledge in this area I
was not sure. I am running a new background count now (the current one
is only a few months old). It has been raining a lot, the weather has
turned cold and the heat is on. I suspect all of these items could cause
a rise in the radon levels in our lab.

This was an interesting problem.
Roger Moroney
Radiation Specialist
Mallinckrodt Nuclear Medicine
wrmoroe@mkg.com
314.770.7457 voice & 7998 fax