UNCLASSIICD
sure data on emploveesatdifferentsites, or within sites
over time, have varied widely. In the earlier years only
a fraction of the workers were monitored, and there
was s¢nousrisk of under-reporting exposures. At some
sites, for many workers, it is impossible to distinguish
between unmonitored years and years with a zero dose.
At othersites, a zero dose was recorded for any exposure below the threshold of film badges. In one case
spurious “correction factors” were invented to lower
exposure figures and give some workers a “negative
radiation dose,” something that does not exist in nature. One research team has concluded
that there is “no constant relationship
berween recorded doses. . . and actual
workers, and the informationis typically out of date by
five to seven years or more. This is reflected by the
limited length of follow-up reported in manystudies.
For most nuclear weapons workers covered by the
published studies, follow-upis far short
of the period required before many
forms of cancer, especially solid tumors, appear. Such studies are therefore radically incomplete, and the
reported absence ofsignificant findings may constitute a false reassurance. These deficiencies are more
scrious in view of a few recent studies
finding more cancer deaths during extended follow-up periods. It is noteworthy that those more recent DOE
epidemiologic studies cover
only a relative handful of
the 76 nuclear weapons
.
research, production ond
testing sites.
While some of the DOE’s published srudies may
acknowledge the healthy workereffect, taey rarely regard excess, but not statistically significant, worker
death rates as warning signals. Instead, they tend to
DEAD RECKONING
i
4 Re
Of the cumulative total of approximately 600,000
nuclear weapons workers, large numbers are not represented in published DOEstudies. From 1947 to 1978
at somesites, no exposure data were kept on the employees of subcontractors. Data on thousands ofworkers are incomplete. By 1990, only 250,000 workers
. were represented in computerized databases. At one
site involved in a study ofall workers exposed to 5 rem
of external radiation in any one year, records are so
confused that the true number of workers exposed at
that level may be three times greater than the number
included in the study, and the numberexposedat 4 to
5 rem (many of whom mayin fact have had higher
exposures) is ten times greater. The published DOE
epidemiologic studies cover only a relative handful of
the 76 nuclear weaponsresearch, production andtesting sites. Because DOE sites vary in the industrial
processes they employ, and average radiation exposures
vary widely at different sites, the published research
Many of the benign or dismissive
interpretationsof excess cancerrisk in nuclear weapons
workers as compared to the general population—
interpretations that are consistently found in DOEsponsored studies—give insufficient weight to the
“healthy worker effect,” which predicts /ower risks of
disease for workers. The workforce almost always has
low mortality in comparison to the populationatlarge,
since thelatter includes many more people at high risk
of poor health, who are too sick to work, who lack
good medical care, who have lower average socioeconomic status and higherrates of smoking, etc. Years of
research has taught that overall death rates, and death
rates from specific diseases such as cancer, will be lower
among workers than in the general population. For
example, any comparative increase in death rates for
cancer among workers runs counter to expectations
and calls for further investigation and follow-up. Despite widespread knowledge of the healthy worker effect, studies that are subject to this form ofbias continue
to be conducted; the majority of published DOE studies are plagued by this problem.
rnp
Coverage of the Workforce and of DOE Sites
The “Healthy Worker” Effect and the
Lack of Moritdity Data
wd 7 :
pare workers with higher radiation exposures to those with Jower or no exposures, the only proper method of
analysis. Thereis also a pervasive lack of
data on workers’ medicalirradiation histones, smoking
and other factors which could distort or confuse findings.
ods tend to report higher cancer mortality rates and morefindings that are
statistically significant.
piememe
worse the data, the harderit is to com-
studies which cover longer time peri-
ie
classification bias (mixing exposed and
unexposed workers together, which
would dilute the estimated effect). The
There have been long and inexplicable delays in
gathering death data on many nuclear weapons plant
UNGL
effects and raising the possibility of mis-
Length of Follow-up of Worker Cohorts
The published DOE
doses.” At five important DOEsites,
no radiation exposure data are available
for epidemiologic studies; at others,
computenzation of exposure data and
linkage to individual workers are years
out of date. The great majority of published DOEstudies do not present any
individual-specific exposure data,
thereby limiting the analyses of health
findings may have overlooked someserious hazards to
health.