Re: Radon in urine Part 2

[rfong@snd10.med.navy.mil (LCDR Fong)]

>Hi Les,
Saw your posting.  How's retired life?
Ray Fong
>
>On Sun, 24 Nov 1996, Moroney, Roger W wrote:
>
>> 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
>> 
>Roger,
>  A couple of years ago, during the early part of a rain, a lab person 
>came into the building and when they left the lab a few minutes later, 
>they monitored their shoes with an alpha survey meter (we were working 
>with 239-Pu at the time, very low levels) and they got something like 30+ 
>alpha counts/min.  We made them remove their shoes which we kept.  The 
>alpha counts decayed with the expected rate of 222-Rn progeny.  The only 
>thing we could figure out was that the rain wash out dust with 222-Rn on 
>it, and the person picked it up, as mud-like stuff? - as they walked to 
>the building.
>Les Fraley 
>