Re: MDL and Dose Effects

[Bob Hearn <rah@america.net>]

If there is anyone in Oak Ridge who is unaware of the biased reporting and
practices of Frank Munger, the author of this news article, they should be
educated in regard to his chosen mission of chasing information that may
present ORNL or anything related to radiation in a negative connotation.  It
is appropriate that educated technical individuals such as those who have
responded to this issue on the net thus far should initially address the
technical aspects brought into question. However, as you learned in the
critical analysis instruction in your secondary school English courses, the
content of such material must be digested along with a consideration of the
bias and motivations of the author. We may have understood that certain
journalism such as "news reporting" was similar to technical publication in
the sense that it was an attempt to present facts to reveal the truth,
however, much of our front page coverage today would be relegated to the
editorial section under these standards that were the ideal of a few decades
back. (Likewise with much of the media.) 

While it is fine and of some importance for us to debate the technical
aspects of dealing with values at the limits of measurement capabilities and
statistical validity, this "reporter" should be recognized for his true
colors, and any individual identifiable as a representative of the radiation
community in the Oak Ridge - Knoxville area should be educated as to the
mission of this hype monger (pun intended). This article is another slam of
our profession as hiding the truth for selfish purposes without regard for
harm to others, and, left unrebutted, this slanted smear goes accepted for
the truth. We must respond outside of our own technical community in a
manner that depicts this concern at the level of triviality that it
deserves, possibly adding the note that if exposures were slightly
underestimated, this indicates that radiation is even safer than previously
demonstrated based on the lack of observed effects.

Tankersly should be admonished to reveal the technical basis behind his
recent claim that ''Today . . . even very low exposures are suspected of
contributing to excess disease,'' and be held accountable for the loose
terminology, as should the Journal of Applied Occupational and Environmental
Hygiene, if either is to be credited with technical competence with which
comes attached _an_attendant_responsibility_. 

When a statement with ...dots is presented, a flag should immediately be
raised for an intelligent reader. (Insert above "...in the circles of Ralph
Nader and other persons benefitting from the effects of a public
unreasonably frightened by inconsequential levels of radiation...".) So I
would request that if anyone has access to the original article that the
excerpt be posted here.

While I recognize the difficulty of obtaining the opportunity to respond to
such media slant, we must at least try to make our technical compatriots
aware of the hazards of attaching our credibility to loosely linked words
which are available to our detractors. 

Bob Hearn
rah@america.net
Unaffiliated
Unbiased...well,...


At 09:46 AM 11/4/96 -0600, you wrote:
>This article appeared in today's Knoxville News-Sentinel. It is available on
>the www at:
>
>        http://www.knoxnews.com/features/munlab/fm110496.html
>
>______________________________________________________________________________
>
>Research finds unrecorded radiation data was significant
>
>By Frank Munger News-Sentinel staff writer
>
>
>A researcher at the Oak Ridge Institute for Science and Education has thrown
>another kink into the controversy about low-dose radiation. 
>
>Bill Tankersley's study shows that some nuclear workers at Oak Ridge -- and
>elsewhere -- received radiation doses significantly higher than they thought
>because records did not reflect doses at low levels. 
>
>This stems from the historic practice of recording a zero if the worker's
>dosimeter measured radiation at or below the ''minimum detectable level.'' 
>
>The MDL is the measured level at which authorities believe it is difficult
>to ascertain whether an exposure took place. It also represents a belief
>that even if a worker did receive an exposure at or below the minimum
>detectable level, it was probably insignificant from a health perspective. 
>
>Tankersley's research, however, found that the magnitude of unrecorded doses
>was significant in the 1940s and '50s.
>
>During that period, the Atomic Energy Commission used an MDL of 30 to 50
>millirems. At the same time, film badges used to measure doses were changed
>weekly -- instead of quarterly or even annually as some radiation readings
>are handled today. 
>
>Therefore, an employee whose job regularly exposed him to low-level
>radiation in the range of 30 millirems could have received an unrecorded
>dose of several rems or more over his career. 
>
>This information might not have any direct relevance in determining whether
>an individual worker suffered health effects as a result of radiation doses,
>but Tankersley said the data could provide more insights for epidemiologists
>studying cause-and-effect issues in a population of nuclear workers. 
>
>''Today . . . even very low exposures are suspected of contributing to
>excess disease,'' Tankersley wrote in a paper published earlier this year in
>the Journal of Applied Occupational and Environmental Hygiene. ''Therefore,
>there is increased interest in dose previously considered unimportant.'' 
>
>While reviewing records at Oak Ridge National Laboratory, Tankersley and
>colleagues found a ''substantial and otherwise inexplicable'' increase in
>radiation dose levels among employees after 1956. 
>
>The increase coincided with ORNL's changeover from weekly to quarterly
>monitoring of employee doses. 
>
>''Although the same practice of censoring readings below (30 millirems) was
>continued, the magnitude of the possibly missed or unrecorded dose during
>the period when monitoring was done weekly was many times greater than that
>likely missed for the same reason during quarterly monitoring,'' Tankersley
>wrote. 
>
>He and other researchers also looked at sets of raw dosimetry data from
>workers at the Oak Ridge facilities to evaluate the reliability of low-dose
>results, which traditionally were reported as zero in employee records
>instead of the actual measurement. 
>
>They found that low doses -- ''even those near the zero level'' -- can be
>''rather accurately measured with a relatively large set of data.'' 
>
>In an interview, Tankersley said there is a level of impreciseness with any
>monitoring system, but he said it was particularly important to researchers
>to have as much actual data on radiation exposures as possible when studying
>nuclear workers. 
>
>The low-dose information may be helpful in explaining some reported health
>effects among workers that previously were not understood, he said. 
>
>Donna Cragle, who heads ORISE's Center for Epidemiologic Research, said
>epidemiologists are now trying to incorporate these findings into current
>studies and, in some instances, retrofitting old studies with new
>information if available. 
>
>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
>
>
>
>