Re: MDL and Dose Effects

[croslinsw@ornl.gov (Steve Croslin)]

It might be worthwhile to add that ORNL, and I would assume most other
accredited dosimetry programs, not only have a much lower minimum reportable
dose threshold than in the past, but also now keep the raw data that goes
into dose determination.  This raw data, along with the criteria used to
calculate the minimum reportable dose, will allow epidemiologists and others
to "rehash" the numbers in retrospective studies. (In fact, that is one of
the primary reasons the raw data is maintained.) But it seems open to debate
whether all positive doses, even those with a large uncertainty, should be
reported to the worker. 

Steve Croslin
ES&H Support
P.O. Box 2008
Oak Ridge National Laboratory
Oak Ridge, TN 37831-6017
Phone: (423) 576-5065




>In the study's conclusion, Tankersley wrote: 
>
>''It is not possible to determine accurately the fraction of total dose
>unrecorded due to procedures where all readings less than the applicable MDL
>are set to zero. However, our investigations indicate that, in some cases,
>the amount is considerable.'' 
>
>The administrative practice of recording zeros for radiation doses at or
>below the MDL continues today at the government's Oak Ridge plants and other
>nuclear facilities around the country. However, the minimum detectable level
>for dosimeters is much lower than it used to be, and monitoring period is
>longer, too, which reduces the chance that a significant dose of radiation
>will be missed. 
>
>Nonetheless, Tankersley urged authorities to change the policy and report
>all radiation doses as measured. 
>
>
>Kim McMahan, CHP
>Office of Radiation Protection				    Sola fide ...
>Oak Ridge National Laboratory				  Sola gratia ...
>P.O. Box 2008   Oak Ridge, TN  37831-6290	       Sola scriptura ...
>Ph:  (423) 576-1566				      Soli Deo gloria .
>e-mail: mcmahankl@ornl.gov
>
>
>
>