Re: Spurious TLD results

["Ronald Frick" <RFRICK@gammacorp.com>]

The most recent dosimetry report for one of our hospital clients listed an exposure of 60 to 70 mrem for everyone on the list.  The radiation quality was recorded as high energy x-ray (above 250 keV effective) for most of the badges.  Most of the individuals are x-ray techs and typically  receive 'M' for their monthly dose, and would be expected to be exposed to low effective energies.  The control dosimeters had not been returned with the badges, so no correction could be performed.  When an investigation was performed, it was discovered that the film badges had been left in a room for approximately 1 week before being distributed to personnel, and that a new computer monitor had been placed very close to them.   I would not expect that this would cause the high readings.  Is this a reasonable explanation for these readings?  Since they were not shipped back with controls, another explation could be exposure in transit from some other source.  We will be posing a badge next to the same monitor next month to try to reproduce the results.

Ron Frick
rfrick@gammacorp.com

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