Under the original 1990 memorandum of understanding NIOSH assumed
responsibility for the management of a number of ongoing studies, then
being conducted by four DOE contractors: Oak Ridge Associated
Universities, which became the Oak Ridge Institute for Science and
Education (ORISE); Los Alamos National Laboratory, Battelle Pacific
Northwest Laboratory, and Hanford Environmental Health Foundation.
Approximately 40 research efforts were itemized in the memorandum of
understanding. Ten projects were performed by ORISE, five by Los Alamos
National Laboratory, and five by Hanford Environmental Health Foundation
and Battelle Pacific Northwest Laboratory were transferred for
management by NIOSH. In most of these cases, the research efforts were
well under way by the time of the implementation of the memorandum of
understanding; therefore, NIOSH had minimal opportunity to provide
scientific or technical input. NIOSH worked with these contractors to
complete the studies summarized below:
I. Oak Ridge Institute for Science and Education (ORISE)
The following studies were performed by investigators from the Center
for Epidemiologic Research of ORISE, under the leadership of Donna
Cragle, Ph.D. The analysis of the studies of two sites, X-10 and Y-12,
were conducted by investigators from the University of North Carolina,
as a subcontract to Oak Ridge Associated Universities.
Wing S, Shy CM, Wood JL, Wolf S, Cragle DL, Frome EL [1991].
Mortality among workers at Oak Ridge National Laboratory. JAMA
265(11): 1397-1402.
Summary:
White males hired at the Oak Ridge National Laboratory between
1943 and 1972 were followed up for vital status through 1984
(N=8,318). Relatively low mortality compared with that in U.S. white
males was observed for most causes of death. However, leukemia
mortality was elevated in the total cohort (63% higher, 28 deaths)
and in workers who had at some time been monitored for internal
radionuclide contamination (123% higher, 16 deaths). External
radiation with a 20-year exposure lag was related to all causes of
death (2.68%, increase per 10 mSv), primarily due to an association
with cancer mortality (4.94%, increase per 10 mSv).
Shy C, Wing S [1994]. A report on mortality among workers at Oak
Ridge National Laboratory: followup through 1990. (PO 3C-70837, Final
Report). Oak Ridge, TN: Oak Ridge Associated Universities, 21
pg.
Summary:
This study is a followup of the mortality experience of the
cohort of white males employed at the Oak Ridge National Laboratory,
originally described in 1991 (see preceding manuscript citation). An
additional 586 deaths were identified (compared with 1,524 deaths in
the original followup). The all-cause SMR, the all-cancer SMR, and
lung cancer SMR were unchanged from the previous update; however, the
leukemia SMR was 1.35, compared with 1.63. The SMR for leukemia
declined to 0.71 for the recent followup years (1985-1990). This
decline may reflect a leukemia-radiation association due to
relatively high doses in the 1940s and 1950s.
Loomis D, Wolf S [1996]. Mortality of workers at a nuclear
materials production plant in Oak Ridge, Tennessee, 1947-1990. Am
J Ind Med, 29:131-141.
Summary:
The mortality experience of a cohort of 10,597 males and females
who worked at Y-12 between 1947 and 1974 was somewhat lower than that
of the United States population, and cancer mortality was equal to
that of the general population. Deaths from lung cancer were
significantly elevated (SMR=1.17, 95% CI=1.01, 1.34). Small excesses
of brain and miscellaneous lymphatic cancers were also found
(SMRs=1.13 and 1.32, respectively). A small increase in pancreatic
cancer deaths was also noted (SMR=1.36).
Oak Ridge K-25 Site. Oak Ridge, Tennessee. Date unknown. Photo
courtesy of the U.S. Department of Energy.
Manuscript:
Dupree EA, Wells SM, Watkins JP, Wallace PW, Davis NC [1994].
Mortality among workers employed between 1945 and 1984 at a uranium
gaseous diffusion facility. Oak Ridge, TN: Center for Epidemiologic
Research Medical Sciences Division; Oak Ridge Institute for Science
and Education; (DOE Contract DE-AC05-760R00033, Final report.)
Available from the National Institute for Occupational Safety and
Health/Health-Related Energy Research Branch, Cincinnati, OH, 24
pg.
Summary:
Mortality patterns among 35,712 workers ever employed for 30 days
or more at K-25 between 1945 and 1984 were investigated. For white
males, the SMR for all causes of death was significantly elevated
(SMR=1.03, CI=1.01, 1.05). Other statistically significant increases
among the white male population included cancers of the respiratory
system including lung cancer, cancer of the bone, mental disorders,
and respiratory diseases, and all injuries. Among nonwhite males, no
cause of death showed a statistically significant increase.
Watkins JP, Cragle DL, Frome EL, Reagan JL, West CM,
Crawford-Brown D, Tankersley WG [1997]. Collection, validation, and
treatment of data for mortality study of nuclear industry workers.
Appl Occup Environ Hyg 12(3):195-205.
Summary:
This paper describes methodologic issues related to combining
facilities at Oak Ridge Operations in Tennessee. It includes
evaluation of 118,588 workers employed at TEC, Y-12, K-25, or X-10.
Validation and treatment of data for study members, and
characteristics of their radiation exposure are discussed. Findings
suggest under-ascertainment of external dose during the early years
at two of the facilities.
Frome EL, Cragle DL, Watkins JP, Wing S, Shy CM, Tankersley WG,
West CM [1997]. A mortality study of employees of the nuclear
industry in Oak Ridge, Tennessee. Radiation Res
148:64-80.
Summary:
An analysis was conducted of 27,982 deaths occurring among
106,020 persons employed for at least thirty days at four nuclear
facilities in Oak Ridge, Tennessee [TEC, Y-12 (after 1947), X-10, and
K-25] between 1943 and 1983. Overall mortality and overall cancer
mortality estimates were in close agreement with national rates. The
only notable excesses occurred for lung cancer (SMR=1.18) and
nonmalignant respiratory disease (SMR=1.12) among white males.
Analysis showed that workers employed at TEC, K-25, and multiple
facilities had higher death rates than similar workers employed only
at X-10 and Y-12. These elevations were due to differences among the
facilities for lung cancer, leukemia, and other lymphatic
cancers.
Wells SM, Cragle DL, Tankersley WG [Undated]. An update of
mortality among welders, including a group exposed to metal oxides.
Oak Ridge, TN: Oak Ridge Associated Universities, Oak Ridge Institute
for Science and Education, Center for Epidemiologic Research; (DOE
Contract DE-AC05-76OR00033) Unpublished. 22 pg.
Summary:
Overall mortality and all causes of death were examined among
1,211 white male welders employed at three DOE facilities in Oak
Ridge, from 1943 through 1989. A slight excess in emphysema deaths
was noted in the overall cohort, and a slight excess of deaths from
diseases of the respiratory system among workers exposed to nickel
oxides. The SMR for lung cancer in the total cohort also reached
statistical significance (SMR=1.38, CI=1.03-1.82). Elevations in
deaths due to ulcers and prostate cancer were also noted among
workers exposed to nickel oxides.
Dupree EA, Watkins JP, Ingle JN, Wallace PW, West CM, Tankersly
WG [1995]. Uranium dust exposure and lung cancer risk in four uranium
processing operations. Epidemiology 6(4): 370-375.
Summary:
This study sought to examine the relationship between uranium
dust exposure and lung cancer mortality among workers employed in
four uranium processing or fabrication operations located in
Missouri, Ohio, and Tennessee. A total of 787 cases were identified.
Odds ratios for lung cancer mortality for seven cumulative internal
dose groups did not demonstrate increasing risk with increasing dose.
However, an exposure effect was suggested for workers hired at age 45
years or older. Categorizing workers by facility, and further
analyses for cumulative external dose and exposures to thorium,
radium, and radon did not reveal any statistically significant
association between exposure and increased risk.
Dupree-Ellis E, Watkins JP, Ingle JN, Phillips JA [2000].
External radiation exposure and mortality in a cohort of uranium
processing workers. Am Epidemiol 152:91-95.
Summary:
This study investigated 2,514 white males employed in a uranium
processing plant between 1942 and 1966. Through 1993, a total of
1,013 deaths were ascertained. The SMR for all causes was 0.90 (95%
CI, 0.85-0.96) and 1.05 (95% CI, 0.9 - 1.17) for all cancers.
Respiratory diseases, chronic nephritis, and lymphatic cancers were
significantly elevated. Trend test revealed a statistically
significant increase of kidney cancers with external radiation based
on 10 cases with an excess relative risk of 10.5 per Sv of whole body
exposure. The results must be considered provisional, since external
radiation exposure may be a surrogate for internal radiation dose or
chemical exposures that were not considered in this study.
Fry SA, Dupree EA, Sipe AH, Seiler DL, Wallace PW [1996]. A study
of mortality and morbidity among persons occupationally exposed to
>50mSv in a year: phase I, mortality through 1984. Appl Occup
Environ Hyg 11(4):334-343.
Summary:
This study investigated the mortality experience of 3,145
individuals who reportedly received 50 mSv of penetrating ionizing
radiation in any calendar year of employment (1943 through 1978) at
all facilities operated for DOE. A total of 588 deaths (19%)
occurred. The overall mortality experience of the total white male
cohort was consistent with a healthy worker effect. SMRs for all
causes of death, as well as diseases of the circulatory and digestive
systems, were significantly decreased. SMRs were elevated for cancers
of the esophagus and rectum, for lymphosarcoma, and for benign
neoplasms. However, no statistically significant differences were
found in mortality that were due to these causes or due to cancers of
any of the major organ systems.
II. Los Alamos National Laboratory
The "gadget" in the Trinity Test Site tower awaiting detonation. Built
in 1945 at the Los Alamos National Laboratory. Los Alamos, New
Mexico. July 1945. Photo courtesy of the U.S. Department of Energy.
The following five studies were performed by investigators at Los
Alamos National Laboratory (principal epidemiologist: Laurie Wiggs,
Ph.D.).
Reyes M, Wilkinson GS, Tietjen GL, Wiggs LD, Galke WA [1991].
Mortality among workers at the Mound facility: a preliminary report.
(DOE Contract DE91 010482) Los Alamos National Laboratory, Los
Alamos, NM, 20 pg.
Summary:
This technical report details an investigation of 4,697 white
males employed at least 30 days between 1943 and 1979. No
statistically significant elevations were found for the overall
cohort. However, SMRs for thyroid, pharyngeal, lung, and prostate
cancers were greater than 1.0. Significant elevations in lung cancer
deaths were found among polonium workers employed between 1943 and
1959. Among workers employed for less than two years between 1943 and
1959, significant elevations were found for all causes, lung cancer,
and for all injuries.
Wiggs LD, Cox-DeVore CA, Wilkinson GS, Reyes M [1991]. Mortality
among workers exposed to external ionizing radiation at a nuclear
facility in Ohio. J Occup Med 33(5): 632-637.
Summary:
This study investigated 4,182 white males employed at the Mound
facility between 1947 and 1979. No statistically significant
elevations for overall mortality or site-specific cancers were noted.
A subcohort of 3,229 workers were monitored for external radiation.
This subcohort was assessed for possible dose-response relationships
between mortality from various causes and external exposure to
ionizing radiation. No statistical differences in mortality were
observed between workers exposed to ionizing radiation and unexposed
workers. However, among workers exposed to external radiation, a
statistically significant dose-response relationship was seen for
lymphopoietic/hemotopoietic cancers and for all leukemias.
Wiggs LD, Cox-DeVore CA, Voelz GL [1991]. Mortality among a
cohort of workers monitored for 210Po Exposure: 1944-1972. Health
Phy 61(1):71-76.
Summary:
This study investigated mortality patterns among 2,181 white
males employed at the Mound facility between 1944 and 1972, years in
which polonium-210 was processed and urine monitoring was in place.
The SMR for all causes was less than 1.0. SMRs for cancers of the
thyroid, rectum, esophagus, lymphatic system, oral cavity, and lung
were elevated, though not significantly. Elevated SMRs were seen for
lung cancer among workers employed during WWII, but not for the
post-WWII group. No dose-response relationship was noted between
mortality and exposure to internal radiation.
Wiggs LD, Johnson ER, Cox-DeVore CA, Voelz GL [1991]. Mortality
through 1990 among white male workers at Los Alamos National
Laboratory: Considering exposures to plutonium and external ionizing
radiation. Health Phy 67(6): 577-588.
Summary:
A cohort mortality study was conducted of 15,727 white males
employed at LANL from 1943 to 1977. No cause of death was elevated
among this cohort. Mortality from all causes of death and all cancers
was significantly low, as was mortality from many other
cause-specific categories. SMR analyses were also conducted for a
subcohort of workers first employed during WWII. The SMRs for the
WWII subcohort indicated that mortality in this subcohort was also
low compared with the general population. No cause of death was
significantly elevated. Analyses of mortality comparing
plutonium-exposed with unexposed workers considering a 10-year
induction period also showed that no cause of death was significantly
elevated. However, dose-response relationships were observed for
cumulative dose of external ionizing radiation and cancers of the
brain/central nervous system, esophagus, and Hodgkin's disease.
Wilkinson GS, Tietjen GL, Wiggs LD, Galke WA, Acquavella JF,
Reyes M, Voelz GL, Maxweiler RJ [1987]. Mortality among plutonium and
other radiation workers at a plutonium weapons facility. Am J
Epidemiol 125(2): 231-250.
Summary:
Mortality patterns were examined for 5,413 white males employed
for at least two years at the Rocky Flats Plant from 1952 through
1979. Fewer than expected deaths were observed for all causes, all
cancers, and lung cancer. An excess of brain cancer was found for the
overall cohort. Elevated rate ratios (RRs) for all causes of death
and all lymphopoietic cancers were found, when comparing workers with
plutonium burdens of 2 nCi with those with body burdens < 2 nCi.
Increased RRs were also observed for esophageal, stomach, colon, and
prostate cancers, as well as lymphosarcomas and reticulum cell
sarcomas. When workers with 1 rem were compared with those with <
1 rem cumulative exposure, several elevated RRs were observed
(myeloid leukemia, lymphosarcomas and reticulum cell sarcomas, liver
neoplasm, and unspecified brain tumors). No overall dose-response
relationships were found for either plutonium or external radiation
exposure.
Galke GA, Johnson ER, Tietjen GL [1992]. Mortality in an
ethnically diverse radiation exposed occupational cohort. Los Alamos,
NM: Los Alamos National Laboratory; Unpublished. 70 pg.
Summary:
A total of 5,424 workers employed at Zia between 1946 and 1978
who were monitored for exposure to either plutonium or external
ionizing radiation were included in this retrospective cohort
mortality study. Among male workers, significantly elevated SMRs were
seen for stomach cancer, senility and ill-defined conditions, all
injuries, all incidents, and motor vehicle incidents. SMRs for female
workers were consistent with mortality rates in the general
population. Hispanic male workers, however, had significantly higher
mortality from stomach cancer, all injuries, all incidents, and motor
vehicle incidents. Non-Hispanic males had significantly higher
mortality from all causes, all cancers, lung cancer, all circulatory
diseases, and all respiratory diseases. Stratified rate ratio (RR)
analyses were conducted to test the association between radiation
exposure and mortality. No significantly high RRs were seen in either
Hispanic or non-Hispanic males in the plutonium or external ionizing
radiation analyses.
Voelz GL, Johnson ER, Lawrence JNP [1993]. Mortality of 244 male
workers exposed to plutonium. Los Alamos, NM: Los Alamos National
Laboratory; Unpublished. 16 pg.
Summary:
This paper describes an updated mortality study of 224 male
workers exposed to plutonium at the Los Alamos National Laboratory
and Zia. Study subjects were selected by searching the Los Alamos
plutonium dosimetry records for all workers who were estimated to
have plutonium depositions over 370 Bq. Two types of mortality
analyses were performed: (1) SMRs (calculated as of 1990) based on
mortality rates of white males in the U.S. general population, and
(2) mortality RRs to compare deaths occurring in the exposed group
with those in an unexposed comparison group. The SMRs for all
malignant neoplasms were below 1.0. Only the SMR for bone cancer was
elevated (SMR=10.6, CI=0.15, 59), though this is based on only one
case. All mortality rate ratios (RRs) were calculated with a 10-year
cancer induction time. The ratios for all causes of death and all
malignant neoplasms were not significantly elevated. Only the
standardized rate ratio (SRR) for digestive system cancer was above
1.0 (SRR=1.13, CI=0.42, 3.08).
III. Hanford Environmental Health Foundation
Battelle Pacific Northwest Laboratories
Several research projects were performed jointly by investigators at
the Hanford Environmental Health Foundation(principal epidemiologist:
Ellen Omohundro, Ph.D.) and Pacific Northwest Laboratory (principal
investigator: Ethel Gilbert, Ph.D.). Hanford Environmental Health
Foundation was responsible for the collection and verification of
mortality, occupational history, and medical and personal health history
data. Pacific Northwest Laboratory gathered radiation dosimetry data and
was responsible for data integration and analysis. With the exception of
the combined studies, all the research efforts by these contractors
pertained to the Hanford Site.
Gilbert ES, Omohundro E, Buchanan JA, Holter NA [1993]. Mortality
of workers at the Hanford Site: 1945-1986. Health Phy
64(6):577-590.
Summary:
This study investigated mortality among contractor employees
initially employed at the Hanford site from 1944-1978. Both the SMR
for overall mortality and mortality from malignant neoplasms for all
workers were below 1.0. SMRs for diseases of the musculoskeletal
system among all workers, for cancer of the pancreas in males not
monitored for external radiation, and for all other solid tumors in
males not monitored for external radiation were elevated, but not
significantly. Comparisons of death rates by radiation dose within
the cohort showed no evidence of a correlation for all causes of
death, all cancers, or leukemia with radiation dose. Cancer of the
pancreas (p=0.07) and Hodgkin's disease (p=0.04) showed positive
correlations with radiation dose. Rates for multiple myeloma death in
this cohort continue to be elevated, consistent with a previous
report.
Omohundro E, Gilbert E [1993]. An evaluation of the adequacy of
vital status follow-up in the Hanford Worker Mortality Study.
Richland, WA: Hanford Environmental Health Foundation; (DOE Contract
DE-AC06-76RLO 1830, report prepared for the National Institute for
Occupational Safety and Health/Health-Related Energy Research Branch,
Cincinnati, OH). Available from NTIS, Springfield, VA; DE94005179, 40
pg.
Summary:
This report was designed to evaluate the completeness of vital
status ascertainment in the Hanford worker cohort. Identifying
information about 17,708 Hanford workers was submitted to Equifax
Government and Special Systems. For the period 1945-86, Equifax
ascertained only 12 new deaths. To evaluate the adequacy of the
methods used by Equifax, information about 2,254 Hanford workers who
had been previously identified as dead were also submitted. Equifax
missed less than 2% of known Hanford deaths during 1965-86, but
missed about 18% of deaths occurring before 1965. For the period
1987-89, Equifax identified 49 new deaths. A stratified random sample
of 1,600 of the 17,708 workers with unknown vital status was
submitted to Equifax for a more extensive investigation of followup
status. Information about these workers was compared with consumer
credit databases to determine the last date these workers were known
to be alive. The results of this part of the study indicate that if
these procedures had been applied to all workers with unknown vital
status, about 90% of these workers would have been confirmed to be
alive. About 5% of the total study population would have remained
lost to followup.
Oak Ridge Graphite Reactor, code-named "X-10," produced the world's
first quantities of plutonium. Oak Ridge Graphite Reactor
Landmark, Oak Ridge National Laboratory, Tennessee. Date not
provided. Photo courtesy of the U.S. Department of Energy.
Manuscript:
Gilbert ES, Cragle DL, Wiggs LD [1993]. Update analyses of
combined mortality data on workers at the Hanford Site, Oak Ridge
National Laboratory, and Rocky Flats Nuclear Weapons Plant.
Radiation Res 136:408-421.
Summary:
Combined analyses of mortality data for 44,943 workers from
Hanford, Oak Ridge National Laboratory, (X-10), and Rocky Flats were
undertaken to assess cancer risks associated with protracted low-dose
exposure to ionizing radiation. Of 24 cancer sites evaluated, 12
showed positive correlations with radiation dose, and 12 showed
negative correlations. Cancer of the esophagus, cancer of the larynx,
and Hodgkin's disease showed statistically significant correlations
with radiation dose, but these correlations were likely to have
resulted from bias or chance fluctuations. Evidence of an increase in
the excess relative risk with increasing age at risk was found for
all cancer in both Hanford and Oak Ridge National Laboratory. Both
populations showed significant correlations of all cancer with
radiation dose among those 75 years and older. Although this age
effect may have resulted from bias in the data, its presence suggests
that summary risk estimates for nuclear workers be interpreted
cautiously.
Cardis E, Gilbert E, Carpenter L, Howe G, Kato I, Armstrong BK,
Beral V, Cowper G, Douglas A, Fix J, Fry SA, Kaldor J, Lave C, Salmon
L, Smith PG, Voelz GL, Wiggs LD [1995]. Effects of a low dose and low
rates of external ionizing radiation: Cancer mortality among nuclear
industry workers in three countries. Radiation Res
142:117-132.
Summary:
This paper presents the results of combined analyses of mortality
data for 95,673 workers monitored for external exposure to ionizing
radiation and employed for 6 months or longer in the nuclear industry
in the United States, the United Kingdom, and Canada. No evidence was
found of an association between radiation dose and mortality from all
causes or from all cancers. Mortality from leukemia, excluding
chronic lymphocytic leukemia, showed a statistically significant
association with cumulative external radiation dose. Among 31 other
cancer sites evaluated, a statistically significant association with
external dose was observed only for multiple myeloma. This was
attributable primarily to the associations reported previously in the
Hanford and Sellafield cohorts. The relative risk of all cancers
excluding leukemia was 0.99, and 1.22 for leukemia excluding chronic
lymphopoietic leukemia for a cumulative protracted dose of 100 mSv
compared to 0 mSv.
![[Oak Ridge K-25 Site]](images/2001-133h-1.jpg)
![[Trinity Test Site 'gadget']](images/2001-133h-2.jpg)
![[Oak Ridge Graphite Reactor]](images/2001-133h-3.jpg)
