Some thing you may have wanted to know about the NEC study of DOEworker health

["Dukelow, James S Jr" <jim.dukelow@pnl.gov>]

Bottom line first.  The "final" report of the National Economic Council 
on _The Link Between Exposure to Occupational Hazards and Illnesses in 
the Department of Energy Contract Workforce_ is an enormous improvement 
over the piece-of-trash Preliminary Draft Report that was leaked to the 
NY Times in January.  As it turns out, as the quality of the report has 
improved, it offers less support for the Department of Energy's decision 
to compensate workers assumed to have been sickened by their employment 
at AEC/ERDA/DOE weapons' complex facilities. 

Quoting from the report:

  The question of cancer risk for chronic low dose levels or periodic 
  higher levels of ionizing radiation exposure (e.g., such as may occur 
  in certain occupational settings at DOE facilities) has not yet been 
  completely studied. 

  <snip>

  The panel did not evaluate information on non-DOE populations, such as 
  atomic bomb survivors or populations with occupational exposures such 
  as shipyard workers and medical personnel.  Determining the causal 
  links between an exposure and an illness was not considered to be 
  within the mandate of this panel. 

  <snip>

  For certain facilities and for certain subgroups of workers within 
  these facilities, some evidence suggests a strong association between 
  employment and adverse health outcomes.  Some studies indicate an 
  increased risk of adverse health outcomes with increased risk of 
  exposure to ionizing radiation. 

  <snip>

JSD Note:  Note the "... certain facilities ... certain subgroups ... 
some evidence suggests ... Some studies indicate ...".  This is the key 
to the major failing of the NEC report and many of the epi studies on 
which it is based. 

  The identificaton of excesses of some types of cancers at some 
  facilities and other types of cancers at other facilities is not 
  surprising given the differences in past and present production 
  processes, levels of exposure, and types of radiation and chemical 
  hazards at these DOE facilities. 

  <snip>

  Although data from other radiation exposed cohorts, most notably 
  nuclear shipyard workers, were discussed by the panel members, the 
  results of these studies are not included in this report due primarily 
  to the limited focus and charge of this panel. 

  <snip>

JSD Note:  It might be noted here that the epi studies of the nuclear 
shipyard workers do not seem to support the idea that low-dose radiation 
exposures are harmful. 

JSD Note:  The graph on page 4 of the report shows average deep dose 
equivalent exposure per monitored worker for 1947 to 1997.  For 1947-54, 
the average was 150 mrem.  In 1959, it spiked to 210 mrem, returned to 
150 mrem for 1950 through 1974, dropped to 110 to 90 mrem from 1975 
through 1986, declined to approximately 10-20 mrem by 1990, at which 
level it has remained. 

  As a point of reference, members of the general U.S. population 
  receive an average annual effective dose equivalent of 3.6 mSv (0.36 
  rem) from natural, enhanced natural and man-made sources of ionizing 
  radiation. 

  <snip>

JSD Note:  The report has a table describing different components of the 
360 mrem U.S. average background radiation.  A footnote notes that 
smoking provides an estimated effective dose equivalent to a segment of 
the bronchial epithelium of 16 rem. 

  It has been estimated that more than 40,000 different chemical are 
  present throughout the DOE complex, and some, such as solvents and 
  egreasers, are used in vast quantities.  Most of these chemicals are 
  not unique to DOE sites and are found in other industries.  However, 
  little is known about actual levels of worker exposure to thes 
  materials.  DOE does not maintain a centralized repository of 
  industrial hygiene information on exposures to individual chemicals.  
  To further complicate matters, exposures are often mixtures of 
  substances, making a risk assessment based on the known toxicological 
  profiles of these materials nearly impossible. 

  While chemical hazards have not been either well documented or studied 
  at DOE, a number of reports suggest, either directly or indirectly, 
  that chemical hazards pose a significant health risk to both current 
  and former DOE employees. ... These risks may even exceed those posed 
  by radionuclides. 

  <snip>

  More than 40 studies of DOE contractor workers have been completed to 
  date; there are more than 20 additional studies underway. 

  <snip>

  Overall, DOE production workers had significantly lower age-adjusted 
  death rates compared to the U.S. general population for all causes of 
  death combined; there were two exceptions. (Appendix 5 references 
  LIND87, ORK96). 

  <snip>

  An increase in the risk of dying from specific conditions has been 
  associated with increased exposure to external radiation exposure in 
  seven corhort studies and to internal exposure in two studies. 

JSD Note:  For most (perhaps all) of these trends, the actual SMR 
(standard mortality ratio) was less than 1.0 (that is, the subgroup 
considered was healthier than the general public), but the "healthy 
worker" performance of the subgroup reflected increasing disease with 
increasing exposure. 

  Special studies of workers with brain cancer, multiple myeloma, 
  malignant melanoma, non-malignant respiratory diseases, and malignant 
  respiratory diseases were pursued.  Except for non-malignant 
  respiratory disease among Fernald workers, the special studies did not 
  identify specific occupational exposures associated with the 
  conditions. 

  <snip>

End of quoting from the report.

The report includes at this point a table summarizing Statistically 
Significant ELEVATED [JSD emphasis] Findings for Cancer at Department of 
Energey (DOE) Sites. 

Perhaps the most important thing to note about this table is that 
although almost all sites had significant monitored radiation exposures 
(and none had monitored chemical exposures), there is no consistent 
pattern of disease over the various sites. 

Appendix 3 is a textual summary of statistically significant POSITIVE 
results from the (apparently) 40 studies summarized.  This shares the 
failing of the piece-of-trash preliminary draft that only the POSITIVE 
results are reported.  This allowed Matthew Wald (of the NY Times) and 
other journalists to write things like (paraphrasing) "the NEC report 
shows that DOE workers at 14 sites have suffered 22 different diseases 
caused by their exposure to radiation and hazardous chemicals".  For all 
of that, the most common statement in Appendix 3 was "no cancer cause of 
death was greater than expected based on the general population" or 
"There were no cancer or non-cancer causes of death with rates greater 
than those seen in the U.S. general population." 

Finally, Appendix 4, titled Tables of Standardized Mortality Ratios for 
Epidemiological Studies, includes a wealth of information missing from 
the piece-of-trash Preliminary Draft Report.  There are tables of rank-
ordered SMRs for all of the diseases and from all of the studies 
considered by the NEC review team.  The first table includes ALL SMRs, 
both statistically significant and not, and both elevated and reduced.  
The second and third tables have all of the statistically significant 
ELEVATED SMRs and the fourth table has all statistically significant 
SMRs, both ELEVATED and REDUCED. 

These tables allow the reader to see what the 40 epi studies are really 
saying about the DOE worker cohort. 

The 40 studies calculated 2507 SMRs, considering 84 different diseases 
and conditions.  If the data were completely random and there were no 
health effects due to the chemical and radiation exposures, you would 
expect roughly 125 spurious positive and negative "statistically 
significant" results from these 2507 SMRs (roughly 62.5 positive and 
62.5 negative).  What actually happened? 

There were 78 statistically significant positive results (i.e., more 
disease than the control population) and 263 statistically significant 
negative results (less disease than the control population). 

If you consider various cancers only, there were 32 statistically 
significant positive results vs. 42.17 expected and 138 negative results 
vs. 42.17 expected. 

For non-cancer diseases and conditions, there were 56 staistically 
significant positive results vs. 20.51 expected and 125 statistically 
significant negative results vs. 20.51 expected. 

"Expected" in the previous three paragraphs means the number of spurious 
"statistically significant" results you would expect if there were no 
actual effects of the radiation and chemical exposures. 

This underlines the major failing of the collection of DOE worker epi 
studies.  Basically, they have been reporting their statistical noise as 
significant results and downplaying the fact that, in spite of the 
exposures to radiation and a myriad of ugly chemicals, DOE workers are a 
"healthly worker" population. 

There are some things that stand out in the accumulated data reported in 
the final NEC report.  There is apparently some chemical exposure at 
Rocky Flats that is causing "benign and unspecified neoplasms of the 
brain".  Also, there are some worker populations that don't seem to 
exhibit a healthy worker effect, but they are workers employed at 
several facilities in 1943-45, when most able-bodied men were serving in 
the armed forces. 

The report is available as a PDF file from the DOE web site 
<www.doe.gov>.  Just follow the references to the DOE worker health 
study. 

Best regards.

Jim Dukelow
Pacific Northwest National Laboratory
Richland, WA
jim.dukelow@pnl.gov

These comments are mine and have not been reviewed and/or approved by my 
management or by the U.S. Department of Energy. 


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