Re: Radioactivity in granite building materials

[Tad Blanchard <Tad.M.Blanchard.1@gsfc.nasa.gov>]

A true story about radioactivity in building materials:

For several years our personnel monitoring program used film badges which
were exchanged on a monthly basis.  Personnel badges and controls were hung
on a plastic holder which was mounted to a cement block wall.  No abnormal
or unusual results were reported by the processor.

We changed monitoring periods to "quarterly" and (you guessed it) all the
badges showed low doses ranging from 10-15 millirem, including the control
badge.

I moved the badge board to a cubicle partition within the room and
eliminated this problem.  

Direct measurement with a scinitllation probe revealed readings about
double background.  No definitive measurements were made since personnel
exposure to this low level was considered insignificant (unless they were
continuously present with their "backs to the wall"  :)


At 09:35 PM 2/5/98 -0600, you wrote:
>Does anyone have information or sources concerning the radioactivity in
>granite building materials.  Such as counter-tops, window sills, tiles etc.?
>
>
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Tad  Blanchard            /__ \ /___\   NASA-Goddard Space Flight Center
Nat'l Health Svc, Inc          O         Code 205.9, Greenbelt, MD 20771
Sr Health Physics Tech        / \                    Phone: 301-286-9157
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                 mailto:Tad.M.Blanchard.1@GSFC.NASA.gov
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