Re: P-32/Badging

["Dale E. Boyce" <dale@radpro.uchicago.edu>]

False positives should be evaluated.  With film and perhaps soon
imagible TLD dosimeters, one can tell (sometimes) if it was likely
to have been a one shot exposure.  One shot exposures come from
leaving a badge lying near a source, wearing them during medical
x-ray exams, or any number of other means by which the badge was
exposed, but the individual didn't receive an occupational exposure.
In most cases, these will be small exposures and it is probably not
jumping through the hoops needed to remove it from the official
record.  In these cases it can be explained to the individual and
left on the record.  However, when a badge comes back with say
70 Rem (cGy;) it is in the employers best interest to make sure that it
was not a real exposure, and get it off the record.  Thirty years
from now, when the law suit is filed, no one may remember that it
was a false positive.  In a case several years ago, we had to have a
chromosone abberition count done on an individual who had received
such a film badge exposure.  The count was normal, showing that the
exposure was not to the individual.  The most likely explanation is
that the teletherapy tech to whom the badge was issued left his
labcoat, and badge in the treatment room during treatments.

Dale Boyce
dale@radpro.uchicago.edu