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3.0 COMPLETED PUBLIC HEALTH ACTIVITIES
Executive Summary of Completed Worker Studies 3.1.1-3.1.11
3.1 Issue 1: Worker Exposure
Many studies of worker exposure and health outcomes have been completed
at the Oak Ridge facilities, and are summarized in this report. The reports
are organized on the basis of the site or group of workers comprising
the Oak Ridge facilities.
The first group of studies consists of mortality investigations among
workers at the X-10 facility at Oak Ridge National Laboratory (ORNL),
conducted by researchers at Oak Ridge Associated Universities (ORAU),
and the University of North Carolina (UNC). The population under study
included white males employed at least one month between 1943 and 1983,
who were followed for various periods of time in several investigations,
most recently through 1994. The mortality experience of this group was
compared to that of the general population. Significantly elevated leukemia
and overall cancer mortality were observed among the workers at the later
follow-up time periods. The leukemia mortality was found to be related
to both internal and external radiation exposure. Workers at the X-10
facility were included in several multi-site investigations, as well as
internationally pooled site studies designed to estimate leukemia and
overall cancer mortality risks from exposure to external ionizing radiation.
A second group of studies was conducted at the Y-12 nuclear weapons fabrication
facility on the Oak Ridge Reservation, by researchers at ORAU, UNC, the
University of Michigan, and NIOSH. Y-12 workers were primarily exposed
to internal radiation (specifically, uranium compounds). A variety of
study designs were used to evaluate the association between mortality
and exposure to internal radiation or chemicals (e.g., phosgene gas, mercury)
among white males. In one study, lung cancer was found to be significantly
elevated in workers employed for longer periods or hired at an older age.
Other studies found no significant elevation in mortality among workers
compared to the general population. The most recent follow-up of Y-12
workers, which includes nonwhite and women workers, found significantly
elevated lung cancer mortality compared to the general population. The
Y-12 facility was also part of a multi-site investigation of mortality
among workers exposed to uranium dust. This study did not find significantly
increased mortality with increased internal radiation dose, although there
appeared to be an exposure effect on mortality for workers hired at older
ages. A study of workers exposed to mercury found no differences in mortality
compared to unexposed workers; however, a separate study found evidence
among the exposed of significant declines in neurological function, with
effects remaining for more than 30 years after exposure.
Workers employed at the K-25 gaseous diffusion facility have been studied
for mortality associated with exposure to uranium dust and-separately-to
various chemicals, including epoxy resin, powdered nickel, and nickel
oxides. Among all workers employed for a month or more over a 40-year
period, significant increases in mortality were observed for all causes
of death, respiratory system cancers and other respiratory deaths, bone
cancer, mental disorders, and accidents. Studies have shown workers handling
nickel powder had rates of buccal cavity and pharynx cancer deaths almost
20 times as high as other workers. Welders were not found to have elevated
lung cancer mortality rates. Workers exposed to epoxy resins and solvents
had overall cancer mortality rates similar to those of other workers,
with the exception of bladder cancer. A recent health hazard evaluation
by NIOSH (3.1.10) did not find evidence of cyanide exposure in current
K-25 workers.
A number of studies conducted by ORNL, ORAU, and UNC have combined World
War II-era worker populations from the three Oak Ridge facilities referred
to previously, along with the worker population for the Tennessee Eastman
Corporation. Statistically significant increases in mortality (as compared
to the general population) were observed for several mortality outcomes,
including all causes, respiratory diseases, emphysema, and lung cancer.
Updated follow-up studies of these workers found lung cancer remained
elevated compared to the general population. A separate study found no
significant association between brain cancer and exposure to either chemicals
or internal or external radiation. A combined-site study of a small number
of welders found no significant elevation in mortality (with the exception
of deaths from gastric ulcers); however, a more recent update of the welders
study has found an increased rate of lung cancer compared to the general
population.
Three recently completed studies have combined analysis of Oak Ridge
workers with workers from other sites. A case-control study of uranium
workers found that cumulative internal dose was not significantly related
to lung cancer mortality, although an exposure effect was suggestive for
older workers. Another case-control study found an association between
external radiation and multiple myeloma in workers at Oak Ridge and other
sites. Finally, a NIOSH-sponsored study of childhood cancer at Oak Ridge
and two other sites did not find evidence of an association between childhood
cancer risk and father's radiation work at a DOE site.
3.1.1 Mortality Among Workers at Oak Ridge National
Laboratory
Purpose
The mortality studies were conducted to investigate the mortality rates
among workers at the X-10 complex at Oak Ridge, now the Oak Ridge National
Laboratory.
Findings
The mortality experience of 8,375 white males employed at least a month
between 1943 and 1972 at the Oak Ridge National Laboratory was compared
with the US white male population using standardized mortality ratio (SMR)
analyses in a 1985 paper by Checkoway and others [1]. Increases in deaths
from leukemia (SMR=1.49, 16 recorded deaths), cancer of the prostate (SMR=1.16,
14 recorded deaths), and Hodgkin Disease (SMR=1.10, 5 recorded deaths)
were observed, although none were statistically significant. Dose response
analyses were performed for all causes of death combined, all cancers
combined, leukemia, and prostate cancer and exposed worker death rates
were compared with nonexposed worker death rates. Dosimetry data were
available for the entire period of the study, with the total population
external radiation dose measuring 135 sieverts (Sv). No dose response
gradients were observed. Death rates were calculated for 11 different
job categories by length of time in each job in an attempt to determine
whether specific work environments were related to cancer and leukemia.
Leukemia mortality was observed to be related to length of employment
in engineering and maintenance jobs.
Followup in this cohort was expanded through 1984 in an updated study
by Wing and others [2]. Again, death rates in the worker population were
compared with those in the US population. Nonstatistically significant
increases were noted for cancers of the pancreas (SMR=1.09, 25 recorded
deaths), prostate (SMR=1.05, 26 recorded deaths), brain (SMR=1.04, 15
recorded deaths), and lymphosarcoma and/or reticulosarcoma (SMR=1.05,
9 recorded deaths). There was a significant increase in deaths from leukemia
(SMR=1.63, 28 recorded deaths, 95% confidence interval [CI] 1.08 to 2.35).
The total population external radiation dose was 144 Sv. Dose response
analyses performed for all causes except cancer, lung cancer, and leukemia
did not demonstrate a relationship between level of external radiation
and increased risk of death from these outcomes. There was a significant
dose response relationship (4.94% per 10 millisieverts) between cancer
deaths and level of external radiation dose using models with a 20-year
lag. A subgroup of workers who were monitored for internal contamination
had nonstatistically elevated SMRs for cancer of the prostate (SMR=1.12,
10 recorded deaths) and lymphosarcoma and/or reticulosarcoma (SMR=1.65,
6 recorded deaths). The workers monitored for internal contamination had
a significantly elevated SMR for leukemia (SMR=2.23, 16 recorded deaths,
95% CI 1.27 to 3.62).
A second analysis of the same data by Wing and others [3] looked at the
effect of controlling for a number of possible selection and confounding
factors on the risk coefficient for all cancer dose responses. Models
were adjusted for the following variables with little change in the previously
reported risk coefficient: employment during the World War II era; short-term
employment; job category; and exposure to beryllium, lead, and mercury.
The authors concluded that the previously calculated dose response estimate
was fairly stable when adjustments were made for a wide range of potential
confounders that were not explored in the earlier study.
A followup of the mortality experience of the cohort of white males employed
at the was conducted in 1994 [4]. An additional 586 deaths were identified
(compared to 1,524 deaths in the original followup). The all-cause SMR,
the all-cancer SMR, and lung cancer SMR were all unchanged from the previous
update; however, the leukemia SMR was 1.35 as compared with 1.63. The
SMR for leukemia declined to 0.71 for the recent followup years (1985-1990),
possibly reflective of a leukemia-radiation association and relatively
high doses in the 1940s and 1950s.
Other Studies That Include the Oak Ridge National Laboratory
A combined site mortality study included workers from Oak Ridge National
Laboratory, the Hanford site and the Rocky Flats plant [7]. Two earlier
analyses of these cohorts indicated that risk estimates calculated through
extrapolation from high-dose data to low-dose data did not seriously underestimate
risks of exposure to low-dose radiation [8, 9]. The updated analyses were
performed to determine whether the extrapolated risks represented an overestimation
of the true risk at low doses. The study population consisted of white
males who were employed at one of the three facilities for at least 6
months and monitored for external radiation. The Hanford population also
included females and nonwhite workers. The total population dose was 1237
Sv. Analyses included trend tests for site-specific cancer deaths and
several broad noncancer categories. Statistically significant trends were
noted for cancer of the esophagus, cancer of the larynx, and Hodgkin Disease.
These cancers were not related to radiation exposure levels in previously
published studies. Excess relative risk models were calculated for the
combined DOE populations and for each DOE site separately. Without exception,
all risk estimates included the possibility of no risk (i.e., the confidence
interval for the risk coefficient went from below zero to above zero.
There was evidence of an increase in the excess relative risk for cancer
with increasing age in the Hanford and Oak Ridge National Laboratory populations;
both populations showed significant correlations of all cancer with radiation
dose among those 75 years and older.
An international effort to pool data from populations exposed to external
radiation included the Oak Ridge National Laboratory population in addition
to other radiation worker populations in the United States, Canada, and
Britain. The IARC Study Group on Cancer Risk among Nuclear Industry Workers
made direct estimates of cancer mortality due to low doses of ionizing
radiation [10]. The excess relative risk for death from leukemia, excluding
chronic lymphocytic leukemia, was 2.2 per Sv (90% CI 0.1 to 5.7). This
estimate is intermediate between the linear estimate of 3.7 per Sv and
the linear-quadratic estimate (as used in recent leukemia risk assessments)
of 1.4 per Sv derived from Japanese atomic bomb survivors' data. The excess
relative risk for death from all cancers, excluding leukemia, was -0.07 per Sv (90% CI, -0.4 to 0.3). This estimate
is consistent with a range of risks varying from negative to nearly twice
those estimated from atomic bomb survivors (0.18 per Sv). A more detailed
analysis of the cohort by Cardis and others comprised 95,673 workers (85.4%
men) employed 6 months or longer [11]. The population dose was 3,843 Sv.
There was no evidence of an association between radiation dose and mortality
from all causes or from all cancers. In addition to the significant dose-response
relationship with leukemia, excluding chronic lymphocytic leukemia, there
is a dose-response relationship for multiple myeloma (excess relative
risk not computed; 44 recorded deaths). The study provides little evidence
that the estimates that form the basis of current radiation protection
recommendations are appreciably in error.
Background and Agencies Involved
The mortality studies published before 1991 were conducted for DOE by
researchers at the Oak Ridge Associated Universities and by their subcontractors
at the University of North Carolina. Subsequent studies were managed by
NIOSH with program funding from DOE. The NIOSH-managed study was performed
by investigators from the Center for Epidemiologic Research at Oak Ridge
Institute for Science and Education (ORISE) under the leadership of Donna
Cragle, PhD. The analysis of studies of two sites (X-10 and Y-12) were
conducted by investigators from the University of North Carolina as a
subcontractor to the Oak Ridge Associated Universities.
Publications
[1] Checkoway H, Mathew RM, Shy CM, Watson JE Jr, Tankersley WG, Wolf
SH, Smith C, Fry SA. Radiation, work experience, and cause specific mortality
among workers at an energy research laboratory. British Journal of Industrial
Medicine 1985;42(8):525-533.
[2] Wing S, Shy CM, Wood JL, Wolf S, Cragle DL, Frome EL. Mortality among
workers at Oak Ridge National Laboratory. Evidence of radiation effects
in follow-up through 1984. Journal of the American Medical Association
1991; 265:1397-1402. Published errata appears in JAMA 1991; 266:657.
[3] Wing S, Shy CM, Wood JL, Wolf S, Cragle DL, Tankersley W, Frome EL.
Job factors, radiation and cancer mortality at Oak Ridge National Laboratory:
follow-up through 1984. American Journal of Industrial Medicine 1993;
23:265-279. Published errata appears in American Journal of Industrial
Medicine 1993; 23:673.
[4] Shy C, Wing S. A report on mortality among workers at Oak Ridge National
Laboratory: Followup through 1990. Draft Final Report, March 31, 1994.
[5] Wing SB, Richardson, DB. Time-related factors in radiation-cancer
dose response. Final Report for NIOSH Grant No. R03 OH03343, August 5,
1997.
[6] Richardson DB, Wing S. Methods for investigating age differences
in the effects of prolonged exposures. American Journal of Industrial Medicine 1998;33:123-130.
[7] Gilbert ES, Cragle DL, Wiggs LD. Updated analyses of combined mortality
data for workers at the Hanford Site, Oak Ridge National Laboratory, and
Rocky Flats Weapons Plant. Radiation Research 1993; 136:408-421.
[8] Gilbert ES, Fry SA, Wiggs LD, Voelz GL, Cragle DL, Petersen GR. Methods
for analyzing combined data from studies of workers exposed to low doses
of radiation. American Journal of Epidemiology 1990; 131:917-927.
[9] Gilbert ES, Fry SA, Wiggs LD, Voelz GL, Cragle DL, Petersen GR. Analyses
of combined mortality data on workers at the Hanford Site, Oak Ridge National
Laboratory, and Rocky Flats Nuclear Weapons Plant. Radiation Research
1989; 120:19-35.
[10] IARC Study Group on Cancer Risk among Nuclear Industry Workers.
Direct estimates of cancer mortality due to low doses of ionising radiation:
an international study. Lancet 1994; 344:1039-1043.
[11] Cardis E, Gilbert ES, Carpenter L, Howe G, Kato I, Armstrong BK,
Beral V, Cowper G, Douglas A, Fix J, Fry SA, Kaldor J, Lavé C,
Salmon L, Smith PG, Voelz, GL, Wiggs LD. Effects of low doses and low
dose rates of external ionizing radiation: cancer mortality among nuclear
industry workers in three countries. Radiation Research 1995; 142:117-132.
Time Line
The initial cohort mortality study was completed in 1985 and the most
recent in 1998. The paper published in 1993 was an indepth analysis of
selected occupational factors based on the 1991 publication. The 1995
international study did not report the results individually.
3.1.2 Mortality of Workers at a Nuclear Materials
Production Plant at Oak Ridge (Y-12)
Purpose
Studies were conducted to investigate mortality among workers at the
Y-12 installation, which is a part of the Oak Ridge Reservation.
Findings
The Y-12 plant is a nuclear weapons materials fabrication facility where
the radiologic exposure of greatest concern is internal exposure from
inhalation of uranium compounds. The Tennessee Eastman Corporation managed
the plant from 1943 to 1947. Polednak and Frome reported a followup through
1974 of all 18,869 white male workers employed at Y-12 from 1943 to 1947
[1]. The workers included those exposed to various levels of uranium compounds
in air within the various chemistry and process operations areas located
within two departments known as Alpha and Beta. Electrical workers who
performed maintenance in the exposed areas, and other nonexposed workers
were used as the lowest exposed group for comparisons. Individual measures
of exposure were not available for any members of this cohort, so exposure
levels were inferred from plant areas of work and jobs. High average air
levels of uranium dust were documented in departments employing chemical
workers. Elevated SMRs were observed for mental, psychoneurotic, personality
disorders (SMR=1.36, 36 recorded deaths), emphysema (SMR=1.16, 100 recorded
deaths), diseases of the bones and organs of movement (SMR=1.22, 11 recorded
deaths), lung cancer (SMR=1.09, 324 recorded deaths), and external causes
of death (SMR=1.09, 623 recorded deaths). The lung cancer SMR was greater
among workers employed for 1 year or more compared with workers employed
less than 1 year and was more pronounced in workers hired at the age of
45 or older (odds ratio=1.51; 95% CI, 1.01 to 2.31). Of the workers employed
after the age of 44, the SMR for lung cancer was greatest for electrical
workers (SMR=1.55, 7 recorded deaths), alpha chemistry workers (SMR=3.02,
7 recorded deaths) and beta process workers (SMR=1.51, 11 recorded deaths).
The portion of the Y-12 cohort employed between 1947 and 1974 was described
in a study by Checkoway and others [2]. This study included 6,781 white
male workers first employed at Y-12 between 1947 and 1974 who were employed
for at least 30 days. Mortality data were collected for the cohort through
the end of 1979 and were used to perform SMR and cause-specific dose-response
analyses. Nonstatistically significant increases were observed for all
cancers (SMR=1.01, 196 recorded deaths), diseases of the blood-forming
organs (SMR=1.48, 3 recorded deaths), kidney cancer (SMR=1.22, 6 recorded
deaths), brain cancer (SMR=1.80, 14 recorded deaths), and other lymphatic
cancers (SMR=1.86, 9 recorded deaths). A statistically significant increase
in deaths from lung cancer (SMR=1.36, 89 recorded deaths; 95% CI, 1.09
to 1.67) was observed compared with the US lung cancer rates, but not
with Tennessee lung cancer rates (SMR=1.18, 95% CI, 0.95 to 1.45). Dose-response
analyses for lung cancer and internal alpha radiation dose and external
gamma radiation dose did not reveal a positive relationship for a 0-year
or 10-year lag. Examination of lung cancer rates distributed across both
internal and external dose categories suggested a dose-response with external
radiation dose among individuals who had five or more rems of internal
dose. Brain cancer was not related to the level of internal or external
radiation dose.
The Y-12 cohort study by Checkoway in 1988 was updated with recorded
deaths through the end of 1990 by Loomis and Wolf and included African-American
and white female workers [3] . The dose-response analyses were not included
in the update; therefore, only SMR analyses are reported. For all workers
examined as a group, nonstatistically significant elevations were observed
for cancer of the pancreas (SMR=1.36, 34 recorded deaths), skin cancer
(SMR=1.07, 11 recorded deaths), breast cancer (females only, SMR=1.21,
11 recorded deaths), prostate cancer (SMR=1.31, 36 recorded deaths), kidney
cancer (SMR=1.30, 16 recorded deaths), brain cancer (SMR=1.29, 20 recorded
deaths), cancers of other lymphatic tissues (SMR=1.32, 22 recorded deaths),
and diseases of the blood-forming organs (SMR=1.23, 6 recorded deaths).
The SMR for lung cancer was statistically significant (SMR=1.17, 202 recorded
deaths; 95% CI, 1.01 to 1.34), particularly in the white male segment
of the population (SMR=1.20, 194 recorded deaths; 95% CI, 1.04 to 1.38).
Examination of the lung cancer mortality by year of hire, latency, duration
of employment and calendar year at risk indicated the excess was confined
to those who were first hired before 1954 (SMR=1.27, 161 recorded deaths),
and was greatest in persons employed 5 to 20 years with 10 to 30 years
of followup. Elevated lung cancer mortality was first evident between
1955 and 1964 and continued to increase from 1975 to 1979, followed by
a decrease in lung cancer death rates.
Phosgene: During the early operation of the Y-12 plant from 1942-1947,
a group of male workers was exposed to phosgene gas on a chronic basis.
This exposure group was first described by Polednak in 1980 when he analyzed
recorded deaths through 1974 [4]. In 1985, Polednak and Hollis updated
the study [5]. There were 694 men with chronic exposure to phosgene and
106 men who received acute exposures, along with 91 females. A control
group of 9,280 workers who also worked at Y-12 during the same era but
who did not have phosgene exposure was also described. All groups were
followed through the end of 1978. The SMRs for the chronically exposed
group and the control group were similar for all causes examined. There
was no evidence for increased mortality from respiratory diseases in this
group, and the SMR for lung cancer, while elevated, was similar to the
lung cancer SMR for workers in the rest of the plant. Among those with
acute exposures, the SMR for respiratory diseases was elevated (SMR=2.66,
5 recorded deaths), and this elevation may be related to residual lung
damage from the acute phosgene exposure. It was difficult to trace the
vital status of the 91 women; therefore, description of these highly-exposed
workers was limited to listing the frequency of their initial symptoms
after exposure. As expected, nausea, vomiting, and cough were the most
frequently reported symptoms. Unexpectedly, the women experienced a lower
frequency of pneumonitis than their male counterparts.
Uranium dust study: Workers employed between 1943 and 1947 were subjects
in a combined case-control lung cancer study and exposure to uranium dust
at the Tennessee Eastman, Y-12, Fernald, and Mallinckrodt facilities [6].
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, there was a suggestion of an exposure
effect for workers hired at age 45 years or older. Further analyses for
cumulative external dose and exposures to thorium, radium, and radon did
not reveal any clear association between exposure and increased risk,
nor did categorizing workers by facility.
Background and Agencies Involved
The studies were conducted by scientists at the Oak Ridge Associated
Universities and their subcontractors at the University of North Carolina
for DOE (studies 1, 2, 4, and 5) and NIOSH (studies 3 and 6) with program
funding from DOE.
Publications
[1] Polednak AP, Frome EL. Mortality among men employed between 1943
and 1947 at a uranium-processing plant. Journal of Occupational Medicine
1981; 23:169-178.
[2] Checkoway H, Pearce N, Crawford-Brown DJ, Cragle DL. Radiation doses
and cause-specific mortality among workers at a nuclear materials fabrication
plant. American Journal of Epidemiology 1988; 127:255-366. Comment in:
American Journal of Epidemiology 1989; 129:639-640.
[3] Loomis DP and Wolf SH. Mortality of workers at a nuclear materials
production plant at Oak Ridge, Tennessee, 1947-1990. American Journal
of Industrial Medicine 1996; 29:131-141. Comment in: American Journal
of Industrial Medicine 1997; 31:121.
[4] Polednak AP. Mortality among men occupationally exposed to phosgene
in 1943-1945. Environmental Research 1980; 22:357-367.
[5] Polednak AP and Hollis DR. Mortality and causes of death among workers
exposed to phosgene in 1943-45. Toxicology and Industrial Health 1985;
1:137-151.
[6] Dupree EA, Watkins JP, Ingle JN, Wallace PW, West CM, Tankersley
WG. Uranium dust exposure and lung cancer risk in four uranium processing
operations. Epidemiology 1995 Jul;6(4):370-375.
Time Line
Studies of Y-12 were initiated in the 1970s with the first publication
about phosgene exposure in 1980 and the first cohort mortality study in
1981. The most recent study was published in 1996, but did not include
information about occupational exposures.
3.1.3 Morbidity and Mortality Among Workers Employed
at a Uranium Gaseous Diffusion Facility at Oak Ridge (K-25)
Purpose
Studies of workers were conducted to investigate mortality rates and
cancer incidence rates at the K-25 plant, a part of the Oak Ridge Reservation.
Findings
The K-25 site enriched uranium beginning in 1945, using a gaseous diffusion
process. There was potential exposure to uranium dust, oxidized uranium
compounds, uranium hexafluoride, and a number of chemical compounds used
in the process. In later years of operation, the gas centrifuge process
was used to enrich uranium.
Mortality patterns among 35,712 workers ever employed for 30 days or
more at K-25 between 1943 and 1984 were investigated [1]. For white males,
the SMR for all causes of death was significantly elevated (SMR=1.03,
CI, 1.01 to 1.05). Other statistically significant increases among the
white male population included cancers of the respiratory system and deaths
from other respiratory diseases, cancer of the bone, mental disorders,
and accidents. Nonwhite males did not have statistically significant increases
in all causes of death combined and all cancer combined.
Nickel study: Powdered nickel was used at K-25 in the production of the
barrier material used to separate and enrich uranium. Workers who fabricated
the barrier material were exposed to nickel powder through inhalation.
Cragle and others [2] updated an earlier study [3] of 814 workers who
were employed in the manufacture of barrier material between 1948 and
1953. A comparison group of 7,552 white males employed at K-25 sometime
between 1948 and 1953 was selected. The SMRs in the barrier group were
similar to those in the nonbarrier worker group for most noncancer outcomes.
The nickel workers were noted to have a higher rate of death from cancers
of the buccal cavity and pharynx (SMR=2.92, 3 recorded deaths) than the
nonnickel workers (SMR=0.23, 3 recorded deaths). When the directly standardized
rates were compared, the rate of buccal cavity and pharynx cancer in the
nickel workers was approximately 19 times higher than the rate in the
nonnickel workers. The authors acknowledge that the number of cases is
quite small and recommended additional followup to determine if this trend
continued. There were no nasal sinus cancers observed in the worker population
exposed to metallic nickel, in contrast to workers in nickel refineries
where the rates of sinus cancer related to nickel compounds are quite
high.
Centrifuge process study: K-25 workers employed in the gas centrifuge
process were the focus of an interview study by Cragle and others [4].
The study was conducted in order to determine the incidence rate for cancer
and illness symptoms among workers exposed to epoxy resin and solvents
prevalent in the process. A total of 263 workers determined to have worked
closest and longest to the process were compared with 271 employees who
were employed at the plant during the same time but did not work in the
centrifuge process. The centrifuge workers and the noncentrifuge workers
had similar overall cancer incidence rates. However, the centrifuge workers
reported five incident bladder cancers versus none reported by the noncentrifuge
group. The centrifuge workers also reported significantly more rashes,
dizziness, and numb or tingling limbs during employment, which are symptoms
of high solvent exposure. One of the epoxy resins used in the early years
of the process was a potential bladder carcinogen, but none of the workers
with bladder cancer had jobs that required routine, hands-on work with
the material. A specific causative agent for the increase in bladder cancer
was not identified.
Welders study: Causes of death among 1,059 white male welders employed
between 1943 and 1973 at the Y-12 plant, the K-25 site, and were studied
by Polednak [5]. A subgroup of 536 welders exposed to nickel oxides (possible
respiratory carcinogens) at K-25 were compared with 523 welders at the
other two facilities. The risk of lung cancer and other respiratory diseases
did not differ between the two groups. Wells and others updated the welder
study for those employed through 1985 with additional deaths through 1989
[6]. The mortality from gastric ulcers was significantly higher than expected
compared to the other two facilities (SMR=4.04, 5 recorded deaths). Prostate
cancer was elevated but not statistically significant based on 5 recorded
deaths. Results for the full cohort study are found in the Studies of
Combined Oak Ridge Facilities.
Background and Agencies Involved
Studies were conducted by scientists from the Oak Ridge Associated Universities.
Studies 2, 3, and 5 were conducted for DOE. Studies 1, 4, and 6 were conducted
for NIOSH with program funding from DOE.
Publications
[1] Dupree EA, Wells SM, Watkins JP, Wallace PW, Davis NC. Mortality
among workers employed between 1945 and 1984 at a uranium gaseous diffusion
facility. Draft Report to the National Institute for Occupational Safety
and Health, February 1996.
[2] Cragle DL, Hollis DR, Newport TH, Shy CM. A retrospective cohort
mortality study among workers occupationally exposed to metallic nickel
powder at the Oak Ridge Gaseous Diffusion Plant. In: Nickel in the Human
Environment, IARC Scientific Publications No. 53, 1984; Lyon, International
Agency for Research on Cancer:57-63.
[3] Godbold JH Jr and Tompkins EA. A long-term mortality study of workers
occupationally exposed to metallic nickel at the Oak Ridge Gaseous Diffusion
Plant. Journal of Occupational Medicine 1979; 21:799-806.
[4] Cragle DL, Wells SM, Tankersley WG. An occupational morbidity study
of a population potentially exposed to epoxy resins, hardeners and solvents.
Applied Occupational and Environmental Hygiene 1992; 7:826-834.
[5] Polednak AP. Mortality among welders, including a group exposed to
nickel oxides. Archives of Environmental Health 1981; 36:235-241.
[6] Wells S, Cragle DL, Tankersley WG. Mortality update among welders
at multiple sites. Final Report. Oak Ridge Associated Universities Document
98-0790. National Technical Information Service.
Time Line
The studies were completed between 1979 and 1996.
3.1.4 Mercury Workers Health Studies
Purpose
Studies of mercury workers were conducted to investigate the potential
impact of exposure to metallic mercury on mortality, as well as to investigate
the general neurologic health of workers exposed to high levels of mercury.
Findings
Between 1953 and 1963, Y-12 used mercury in a process to produce large
quantities of enriched lithium. Cragle and others studied all 5,663 workers
employed at Y-12 at least 5 months between January 1, 1953, and April
30, 1958 [1]. This group was categorized into workers exposed to mercury
and workers not exposed to mercury based on results of urinalysis data
supplied by the plant. Vital status followup was complete through the
end of 1978, and SMRs were calculated. Compared with nonexposed workers,
there were no differences in the mortality patterns for (1) mercury-exposed
workers as a whole; (2) workers with the highest mercury exposures; and
(3) workers employed more than a year in a mercury process. The authors
acknowledge that mortality is not the optimal end point to assess health
effects related to mercury exposure.
The mercury workers were subjects in a clinical study by Albers and others
who examined 502 Y-12 workers, 247 of whom worked in the mercury process
20 to 35 years prior to the examination [2]. Correlations between declining
neurological function and increasing exposure were identified. An exposure
assessment was determined for each mercury worker during the time of employment
in the mercury process. Study subjects who had at least one urinalysis
equal or greater than 0.6 micrograms per liter of mercury showed decreased
strength, coordination, and sensation along with increased tremor, and
prevalence of Babinski and snout reflexes when compared with the 255 unexposed
workers. Clinical polyneuropathy was associated with the level of the
highest exposure. In the early 1990s, 219 workers exposed to high levels
of mercury between 1953-1963 were invited by Cragle and Letzto receive
a neurologic follow-up examination [3]. Some neurologic effects were still
detectable more than 30 years after cessation of exposure, primarily in
the peripheral nervous system. Postural tremor was also associated with
past mercury exposure. Study subjects were notified individually of their
test results.
Background and Agencies Involved
The studies published before 1989 were conducted by the scientists at
the Oak Ridge Associated Universities and the University of Michigan with
funding from DOE [1] and Martin-Marietta Energy Systems [2]. The clinical
follow-up report was managed by NIOSH with program funding from DOE [3].
Publications
[1] Cragle DL, Hollis DR, Qualters JR, Tankersley WG, Fry SA. A mortality
study of men exposed to elemental mercury. Journal of Occupational Medicine
1984; 26:817-821.
[2] Albers JW, Kallenbach LR, Fine LJ, Langolf GD, Wolfe RA, Donofrio
PD, Alessi AG, Stolp-Smith KA, Bromberg MB. Neurological abnormalities
associated with remote occupational elemental mercury exposure. Annals
of Neurology 1988; 24:651-659.
[3] Cragle, D and Letz R. A study of the health effects of exposure to
elemental mercury: A followup of mercury exposed workers at the Y-12 Plant
in Oak Ridge, Tennessee. Final Report: NIOSH Contract No. 200-93-2629,
1997. Oak Ridge Associated Universities and Emory University.
Time Line
The studies were published from 1984 to 1997.
3.1.5 Studies of Combined Oak Ridge Facilities (Tennessee
Eastman Corporation, Y-12, X-10, K-25)
Purpose
The purpose of the Studies of Combined Oak Ridge Facilities (Tennessee
Eastman Corporation, Y-12, X-10, K-25) is to analyze the overall mortality
rates for Oak Ridge Reservation workers and the mortality rates between
facilities; to conduct indepth analyses of general mortality; and to study
specific rare causes of death.
Findings
Frome and others reported on the mortality experience of World War II
workers employed at the three facilities (Y-12, X-10, K-25) between 1943
and 1947 [1]. Poisson regression analyses were used to control for potential
confounders such as facility of employment, socioeconomic status, period
of followup, and birth year. The cohort included 28,008 white males who
were employed at any Oak Ridge facility at least 30 days between the start
of the operation and 1947 and who were never employed at an Oak Ridge
facility after 1947. Elevated mortality was statistically significant
for all causes (SMR=1.11, 11,671 recorded deaths); tuberculosis (SMR=1.37,
108 recorded deaths); mental, psychoneurotic, and personality disorders
(SMR=1.60, 81 recorded deaths); cerebrovascular disease (SMR=1.11, 833
recorded deaths); diseases of the respiratory system (SMR=1.25, 792 recorded
deaths); emphysema (SMR=1.24, 209 recorded deaths); all accidents (SMR=1.28,
694 recorded deaths); and motor vehicle accidents (SMR=1.44, 339 recorded
deaths). The only elevated site-specific cancer that was statistically
significant was lung cancer (SMR=1.27, 850 recorded deaths). A surrogate
for radiation exposure based on a worker's job and department was used
to indicate the probability of exposure. This surrogate for actual radiation
exposure was not associated with increased rates of cancer.
Frome and others updated the original 1990 study and included all four
facilities in the analyses [2]. The analysis included 27,982 deaths among
106,020 persons employed at four federal nuclear plants in Oak Ridge,
Tennessee, between 1943 and 1985. All-cause mortality and all-cancer mortality
were in close agreement with national rates. The only notable excesses
occurred for white males for lung cancer (SMR=1.18, 1,849 recorded deaths)
and nonmalignant respiratory disease (SMR=1.12, 1,568 recorded deaths).
There are substantial differences in death rates among workers at the
Oak Ridge plants. Workers employed only at Tennessee Eastman Corporation
or K-25 and at multiple facilities had higher death rates than similar
workers employed only at X-10 or Y-12, and the differences are primarily
due to noncancer causes. Analysis of selected cancer causes for white
males indicated large differences among the workers at the different facilities
for lung cancer, leukemia, and other lymphatic cancer. Dose-response analyses
for external penetrating radiation were limited to a subcohort of 28,347
white males employed at X-10 or Y-12. Variables included in the analyses
were age, year of birth, a measure of socioeconomic status, length of
employment, internal radiation exposure potential, and facility. For external
radiation dose with a 10-year lag, the excess relative risk was 0.31 per
Sv (95% CI , -0.16 to 1.01) for all causes, and 1.45 per Sv (95% CI, 0.15
to 3.48) for all cancer. The estimated excess relative risk for leukemia
was negative, but the estimate is imprecise. A preliminary dose adjustment
procedure was developed to compensate for missing dose but not other dosimetry
errors. Results of the analyses using the adjusted doses suggest that
the effect of missing dose is to give risk estimates that are too high.
A detailed review of the dosimetry issues and the validation of dosimetry
information for this study was published separately [3].
Central nervous system cancer: Carpenter investigated earlier reports
of an association between brain cancer and employment at Y-12 by conducting
a case-control study of workers employed between 1943 and 1977 at the
Oak Ridge National Laboratory or Y-12 [4]. Cases consisted of 72 white
males and 17 white females with brain cancer. Four controls were selected
for each case matched on age, sex, cohort, year of birth, and year of
hire. Analyses with respect to internal and external radiation exposures
indicated no association with brain cancer. Two companion papers were
also published from this case-control study; one examined relationships
between brain cancer and chemical exposures, and the other examined nonoccupational
risk factors [5, 6]. No statistically significant association between
the use of the 26 chemicals evaluated and the risk of brain cancer was
observed. The chemicals evaluated included those encountered in welding
fumes, beryllium, mercury, 4,4-methylene bis 2-chloroaniline (MOCA), cutting
oils, thorium, methylene chloride, and other solvents. Excess brain cancer
was observed, however, among individuals employed for more than 20 years
(odds ratio=7.0, 9 cases ; 95% CI, 1.2 to 41.1). Analysis of 82 cases
with complete medical records revealed an association with a previous
diagnosis of epilepsy (odds ratio=5.7, 4 cases; 95% CI, 1.0 to 32.1) recorded
for pre-employment and health status followup.
Welders combined: Causes of death among 1,059 white male welders employed
between 1943 and 1973 at the Y-12 plant, the K-25 site, and the were studied
by Polednak [7]. Based on deaths reported through 1974, mortality from
all causes for welders was slightly lower than that expected based on
death rates for US white males (SMR=0.87, 173 recorded deaths). Nonstatistically
significant decreases in mortality were also observed for all cancers
(SMR=0.88, 32 recorded deaths), especially digestive cancer (SMR=0.49,
5 recorded deaths); diseases of the circulatory system (SMR=0.74, 72 recorded
deaths); diseases of the digestive system (SMR=0.76, 9 recorded deaths);
and accidents (SMR=0.89, 16 recorded deaths). Nonstatistically significant
increases were noted for lung cancer (SMR=1.50, 17 recorded deaths); diseases
of the respiratory system (SMR=1.33, 13 recorded deaths), especially emphysema
(SMR=2.21, 6 recorded deaths); and suicide (SMR=1.64, 10 recorded deaths).
A subgroup of 536 welders exposed to nickel oxides (possible respiratory
carcinogens) at K-25 were compared with 523 welders at the other two facilities.
The risk of lung cancer and other respiratory diseases did not differ
between the two groups. Wells and others updated the welder study for
those employed through 1985 with additional deaths through 1989 [8]. The
mortality from all causes was slightly higher than the earlier analysis
(SMR=1.04, 463 recorded deaths), and there was a statistically significant
excess of deaths from gastric ulcers among K-25 welders (SMR=4.04, 5 recorded
deaths). In the X-10/Y-12/Tennessee Eastman subgroup, there was a statistically
significant excess of deaths from prostate cancer (SMR=2.33), while among
K-25 welders the excess was slight. Welders, overall, had more lung cancer
than expected (SMR=1.38), and the rate reached statistical significance.
There were slight, but not statistically significant, excesses for both
prostate cancer and emphysema.
Background and Agencies Involved
All the research was conducted by scientists at the Oak Ridge National
Laboratory, Oak Ridge Associated Universities, and their subcontractors
at the University of North Carolina for DOE [1, 4, 5, 6, and 7] and NIOSH
[2, 3, and 8] with program funding from DOE.
Publications
[1] Frome EL, Cragle DL, McLain RW. Poisson regression analysis of the
mortality among a cohort of World War II nuclear industry workers. Radiation
Research 1990; 123:138-152.
[2] Frome EL, Cragle DL, Watkins JP, Wing S, Shy CM, Tankersley WG, West
CM. A mortality study of employees of the nuclear industry in Oak Ridge,
Tennessee. Radiation Research 1997; 148:64-80.
[3] Watkins JP, Cragle DL, Frome EL, Reagan JL, West CM, Crawford-Brown
D, Tankersley WG. Collection, validation, and treatment of data for mortality
study of nuclear industry workers. Applied Occupational and Environmental
Hygiene 1997; 12.
[4] Carpenter AV, Flanders WD, Frome EL, Crawford-Brown DJ, Fry SA. CNS
cancers and radiation exposure: a case-control study among workers at
two nuclear facilities. Journal of Occupational Medicine 1987;29:601-604.
[5] Carpenter AV, Flanders WD, Frome EL, Tankersley WG, Fry SA. Chemical
exposures and central nervous system cancers: a case-control study among
workers at two nuclear facilities. American Journal of Industrial Medicine
1988; 13:351-362.
[6] Carpenter AV, Flanders WD, Frome EL, Cole P, Fry SA. Brain cancer
and nonoccupational risk factors: a case-control study among workers at
two nuclear facilities. American Journal of Public Health 1987; 77:1180-1182.
[7] Polednak AP. Mortality among welders, including a group exposed to
nickel oxides. Archives of Environmental Health 1981; 36:235-241.
[8] Wells S, Cragle DL, Tankersley WG. Mortality update among welders
at multiple sites. Final Report. Oak Ridge Associated Universities Document
98-0790. National Technical Information Service.
Time Line
These special studies were published over a period of 11 years. The most
recent studies of mortality patterns and of dosimetry issues appeared
in 1997.
3.1.6 Welders at Oak Ridge Facilities
Purpose
A study of welders at Oak Ridge examined the overall mortality and all
causes of death among 1,211 white male welders employed at three DOE facilities
in Oak Ridge, for 1943 through 1989.
Findings
There was a slight excess in emphysema deaths 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
to 1.82). Elevations in deaths due to ulcers and prostate cancer were
also noted among workers exposed to nickel oxides.
Background and Agencies Involved
This study of welders at Oak Ridge was conducted by the Oak Ridge Associated
Universities researchers under the sponsorship and management of DOE.
Publication
Wells S, Cragle D, et al. An update of mortality among welders, including
a group exposed to nickel oxides. Final Report, Oak Ridge Associated Universities
Document 98-0790. National Technical Information Services.
Time Line
A draft final report was completed in 1994.
3.1.7 Uranium Case-Control Study (TEC, Y-12, Fernald,
Mallinckrodt)
Purpose
A uranium case-control study was conducted 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.
Findings
A total of 787 lung cancer cases were identified. Odds ratios for lung
cancer mortality for seven cumulative internal dose groups did not demonstrate
increasing risk with increasing dose. There was a suggestion, however,
of an exposure effect for workers hired at age 45 or older. Further analyses
for cumulative external dose and exposures to thorium, radium, and radon
did not reveal any clear association between exposure and increased risk,
nor did categorizing workers by facility.
Background and Agencies Involved
The study was originally sponsored by DOE, managed by NIOSH, and performed
by investigators from the Center for Epidemiologic Research of the Oak
Ridge Associated Universities, under the leadership of Elizabeth Dupree
and Janice Watkins.
Publication
Dupree E, Watkins J, et al: Uranium dust exposure and lung cancer risk
in four uranium processing operations. Epidemiology 6(4): 370-375, 1995.
Time Line
The manuscript was published in 1995.
3.1.8 Multi-Site Multiple Myeloma Case-Control Study
Purpose
This multi-site case-control study evaluated possible etiologic risk
factors for multiple myeloma, focusing on external radiation and chemical
exposures. The study complemented a leukemia case-control study being
done at the same sites and the multiple myeloma case-control study with
internal radiation exposure being conducted at the Oak Ridge gaseous diffusion
plant. Five sites were included in this study: Savannah River, Los Alamos
National Laboratory (LANL), LANL-Zia, Oak Ridge National Laboratory, and
Hanford. The final report and the study files and data have been provided
to NIOSH.
Findings
Extended penetrating radiation doses received at age 45 and above were
found to be associated with multiple myeloma.
Background and Agencies Involved
This study was conducted by the University of North Carolina under the
leadership of Steven Wing, PhD, under contract to the NIOSH Health-Related
Energy Research Branch.
Publication
Materials are currently being submitted for publication.
Time Line
The final technical report was completed in March 1997.
3.1.9 Childhood Leukemia Case-Control Study
Purpose
The Childhood Leukemia Case-Control Study assessed the potential association
between paternal exposure to ionizing radiation and risk of leukemia in
offspring, a finding observed by Gardner et al. (1990). A leukemia study
completed in Sellafield, England, prompted the Centers for Disease Control
to evaluate occupational exposures. This childhood leukemia study follows
up on previous findings of birth defects (central nervous system tumors)
at Hanford.
Background and Agencies Involved
The study is being conducted by the NIOSH Health-Related Energy Research
Branch in a cooperative agreement with Battelle Laboratories with Lowell
Sever, PhD, as principal investigator.
Initiated at the Hanford site, this study was expanded to Oak Ridge and
Idaho. The study included both central nervous system tumors and non-Hodgkin
lymphoma as outcomes. The study found no evidence of association between
childhood cancer risk and father's radiation work at the DOE sites included
in the study. This finding did not change when each site was looked at
separately. Children whose fathers worked at Hanford were at increased
risk for central nervous system cancer as compared to children whose fathers
worked at the other sites. However, this association was based on small
numbers and not statistically significant.
Three other studies since the Sellafield study have not shown an increase
in childhood cancers among children whose fathers were exposed to radiation
prior to their child's conception. This NIOSH- sponsored study agrees
with and supports those study findings.
Time Line
The study was completed in November 1997, and the report and findings
went under external peer review. Final communication of results was presented
to site workers and managers in October 1998.
Status
The Childhood Leukemia Case-Control Study was completed in October 1998.
3.1.10 Cyanide Health Hazard Evaluation at K-25
Purpose
In response to a request from employees of Lockheed Martin Energy Systems,
Inc., who work at the DOE Oak Ridge K-25 site, an investigation was conducted
to investigate possible exposure to cyanides. Employees at the K-25 site
reported headaches, fatigue, depression, muscle aches, sleeplessness,
and muscle tremors. Twenty-two employees were interviewed. Air samples
were collected and analyzed for cyanides.
Findings
Cyanides (gaseous or particulate-borne) were not detected in any of the
NIOSH air samples. The sampling and analytical technique used by NIOSH
investigators was very sensitive; the minimum-detectable concentrations
for the long-term samples were on the order of 1/5000 of the most restrictive
occupational exposure criteria. The sampling strategy was designed to
minimize the likelihood that any airborne cyanide present at the site
would go undetected if it were currently present on a widespread, frequent,
or ongoing basis in measurable concentrations. The air sampling results
show that the employees currently are not experiencing occupational inhalation
exposures of hydrogen cyanide, cyanide salts, or any of a wide variety
of gaseous or particulate-borne compounds that contain the cyanide ion.
Further, no evidence of any occupational exposures to these compounds
by routes other than inhalation was found. A review of routine water-sampling
records indicates that cyanide is not a contaminant in the K-25 water
supply; direct skin contact or ingestion by the hand-to-mouth route is
unlikely among the concerned employees because most of them work in offices
or similar "finished" indoor spaces.
The results of this evaluation indicated that employees are not occupationally
exposed to hydrogen-cyanide, cyanide salts, or a wide variety of other
compounds that contain the cyanide ion. The results of this evaluation
do not support a relationship between the health problems reported by
employees at the K-25 site and chronic, occupational cyanide intoxication
from exposures to those compounds or any other related substances. Recommendations
included improved risk-communication efforts, formal evaluation of procedures
Lockheed Martin Energy Systems, Inc. used to investigate this issue, and
consideration of possible nonoccupational cyanide sources in any future
investigations of this issue.
Background and Agencies Involved
The Hazard Evaluations and Technical Assistance Branch of NIOSH conducts
field investigations of possible health hazards in the workplace to determine
whether any substance normally found in the place of employment has potentially
toxic effects in the concentrations that are used or found in the workplace.
Publication
[1] Blade LM, Worthington KA. Health Hazard Evaluation Report No. HETA-96-0071-2584,
Lockheed Martin Energy Systems, Inc., US Department of Energy Oak Ridge
K-25 Site, Oak Ridge, Tennessee.
3.1.11 Improved Systems for Worker Exposure Surveillance
Purpose
Current workers at DOE sites are exposed to a wide variety of chemical
and radiological agents, and it is becoming increasingly important to
provide adequate surveillance of worker exposures and to store the results
of exposure monitoring efforts so that such records are available for
review and analysis. While many existing occupational exposure monitoring
programs accomplish their original goals, increasing worker concern indicates
that additional occupational health system capabilities are needed in
the identification of significant hazards and in the storage and analysis
of occupational exposure records. The complementary additions to traditional
occupational exposure monitoring systems developed by this study would
improve the application of occupational histories to effective risk-based
interventions, including medical surveillance programs.
This project was carried out at the Y-12 facility of the Oak Ridge DOE
site from 1995 to 1997 with the active cooperation of the facility manager
(Lockheed Martin Energy Systems, Inc.). The work consisted of three major
tasks:
- The review, documentation, and analysis of programs at the Y-12 site
that generate or derive useful data for the assessment of worker exposure
to radiation or chemical hazards. This process included the intended
utility of each program, the worker populations covered, the reason
behind the selection of monitored areas or workers, the relative costs
of each program, and the advantages and disadvantages of observed data
utilization.
- The development and test of new systems for the classification of
workers based on their potential occupational exposures, including computer
software for data management. This process included documentation of
a broad-scale survey of occupational health professionals regarding
hazardous exposure identification and priorities. The product of this
phase was the Potential Exposure Profile (PEPS).
- The development and pilot-testing of a cost-effective computer-based
system which incorporated the hazardous agent inventories by defined
work area developed for the PEPS system into an innovative exposure
duration measurement tool. Measurement of duration involved use of bar-code
technology for monitoring the work locations of individual workers and
the real-time measurement of worker presence in specific work areas.
This system effectively merged work area inventories of hazardous agents
with documented duration of exposure records specific to individual
workers, primarily using readily available computer software programs
for input and output, including report generation. This final research
product was named the Worker Exposure Surveillance System (WESS). The
WESS is designed for easy data merger with traditional occupational
health systems utilizing environmental level analyses, occupational
titles, and area descriptors.
Background and Agencies Involved
This work was carried out by the Center for Epidemiological Research,
Department of Environmental Health Sciences Division, Oak Ridge Associated
Universities, with Mr. William Tankersley as principal investigator. The
work was supported by a grant from the NIOSH Health-Related Energy Research
Branch.
Time Line
This study was completed in March of 1997.
Status
The final report, including the copies of the necessary diskettes for
personal computer use of the Worker Exposure Surveillance System, was
delivered to NIOSH and DOE in June of 1997.
3.1.12 Exposure Assessment of Hazardous Waste, Decontamination
and Decommissioning, and Clean-Up Workers-Phase I Feasibility Study
Purpose
The Exposure Assessment of Hazardous Waste, Decontamination and Decommissioning,
and Clean-Up Workers is a multi-site study. It addresses exposures to
current workers involved in environmental restoration, decommissioning
and decontamination, and handling or storage of hazardous and radiological
waste. Exposures encountered by those workers will be characterized. In
Phase I, background information will be collected at seven DOE sites to
assess working conditions and identify issues and research needs at the
sites. This study will evaluate mixed exposures and also assess the feasibility
of tracking this workforce for future studies.
Background and Agencies Involved
DOE is developing new technologies to clean up and treat hazardous and
radiological wastes that have accumulated within the DOE complex around
the United States. The use of both new and conventional technologies to
clean up the varied and unique DOE sites may expose the workers to new
and old occupational hazards. A broad array of activities involving deactivation,
decontamination, decommissioning, dismantlement, and waste generation
and treatment will contribute to hazards potentially encountered by the
clean-up workforce. NIOSH investigators designed this project to accomplish
several tasks: (1) compile recent information about clean-up activities
at these sites; (2) identify hazards associated with the clean-up activities;
(3) determine the sites where these workplace hazards should be assessed;
and (4) determine whether additional studies of the workforce are needed.
Time Line
Access and data collection problems reported by the NIOSH contractor
led to limitations in the gathered information and a delay in completion
of the document. The final version of the Phase I report for Oak Ridge
has been completed, and distribution of the Phase I report should be completed
in December 2000.
Status
Phase I final reports for each of the designated DOE sites (Fernald,
Mound, Savannah River, Oak Ridge Reservation, Rocky Flats, Hanford, and
the Idaho National Engineering and Environmental Laboratory) studied during
this project have been completed. Distribution of the Phase I final reports
has been completed for Fernald, Mound, Rocky Flats, and Hanford. Distribution
of the Phase I final report for the Idaho National Engineering and Environmental
Laboratory is currently in progress, and the distribution of the final
reports for Savannah River and Oak Ridge should be completed in December
2000.
A technical paper (white paper) that outlines the overall findings and
recommendations from this initial phase has been prepared and is currently
undergoing internal review. After final review, this technical report
will be presented to DOE and made available to workers at the sites; this
will complete the project requirements. This technical report will help
determine future activities for this project. It will also provide workers
and DOE with information on identified issues involving the ability to
further study this workforce concerning potential exposures or with future
epidemiologic studies. In addition, a summary manuscript will be prepared
during fiscal year 2001 and submitted for publication in a scientific
journal.
3.1.13 Prevention of Stress and Health Consequences
of Downsizing and Reorganization
Purpose
The project on Prevention of Stress and Health Consequences of Downsizing
and Reorganization is studying the effects of downsizing on organizational
climate, worker health, and performance at multiple sites. Work-related
conditions implicated in disease development include job dissatisfaction,
lack of job control, and under-utilization of abilities. Sudden job changes
through strike, retirement, layoff, relocation, or job loss may trigger
stress and result in adverse health consequences. This study is applicable
to current and future workers. A feasibility evaluation of intervention
techniques will be conducted following the completion of the study.
Background and Agencies Involved
This study was proposed and conducted through a cooperative agreement
between NIOSH and the Boston University School of Public Health (Lew Pepper,
MD).
Findings from the Oak Ridge Y-12 Plant
1. Workers who felt that the downsizing process was fair, and that communication
was open and honest, reported fewer medical symptoms (e.g., headaches,
shortness of breath, backaches), lower frequency of survivor syndrome,
less job insecurity, and better morale.
1. Workers who were more directly involved with the downsizing process
(i.e., those who received layoff notices, were laid off and then rehired,
changed jobs or departments) reported more medical symptoms, lower levels
of mental health, higher levels of stress, and more job insecurity.
1. Workers in jobs with high workload demands but with low decision-making
authority reported more medical symptoms, more stress, lower morale, and
more job insecurity.
1. Workers who rated their supervisor and coworkers as supportive, and
who felt that their organization had a good relationship with DOE, reported
less stress and better morale.
1. Focus group and interview data yielded the following common themes:
- workload increased after downsizing, causing stress for workers
- lack of effective communication from management
- continued feelings of job insecurity
- lack of trust in upper management
Communication Events
In late October 2000, the Health-Related Energy Research Branch released
a one-page summary of study's results to all five DOE study sites (Pantex,
Oak Ridge Y-12 Plant, Nevada Test Site, Los Alamos National Laboratory,
and Idaho National Engineering and Environmental Laboratory) via fax,
e-mail, bulletin board, newsletter, and website communications. The mass
communications effort was successful in targeting thousands of current
and former workers. Additionally, the Health-Related Energy Research Branch
provided final reports of the study to each site for placement in their
public reading rooms. Copies of the summaries and final reports are available
through the toll-free NIOSH number (1-800-356-4674). Dr. Pepper will conduct
site visits to present study findings in the upcoming months.
Publications
Pepper L [2000]. The Health Effects of Downsizing in the Nuclear Industry:
Findings at the Idaho National Engineering and Environmental Laboratory.
Boston, MA: Department of Environmental Health, Boston University School
of Public Health: (CDC Cooperative Agreement #U60 CCU 112215, Final Report).
Available from the National Institute for Occupational Safety and Health/Health-Related
Energy Research Branch, Cincinnati, OH, 129 pages.
Pepper L [2000]. The Health Effects of Downsizing in the Nuclear Industry:
Findings at the Los Alamos National Laboratory. Boston, MA: Department
of Environmental Health, Boston University School of Public Health: (CDC
Cooperative Agreement #U60 CCU 112215, Final Report). Available from the
National Institute for Occupational Safety and Health/Health-related Energy
Research Branch, Cincinnati, OH, 135 pages.
Pepper L [2000]. The Health Effects of Downsizing in the Nuclear Industry:
Findings at the Nevada Test Site. Boston, MA: Department of Environmental
Health, Boston University School of Public Health: (CDC Cooperative Agreement
#U60 CCU 112215, Final Report). Available from the National Institute
for Occupational Safety and Health/Health-Related Energy Research Branch,
Cincinnati, OH, 125 pages.
Pepper L [2000]. The Health Effects of Downsizing in the Nuclear Industry:
Pantex. Boston, MA: Department of Environmental Health, Boston University
School of Public Health: (CDC Cooperative Agreement #U60 CCU 112215, Final
Report). Available from the National Institute for Occupational Safety
and Health/Health-Related Energy Research Branch, Cincinnati, OH, 133
pages.
Pepper L [2000]. The Health Effects of Downsizing in the Nuclear Industry:
Findings at the Y-12 Plant, Oak Ridge Reservation. Boston, MA: Department
of Environmental Health, Boston University School of Public Health: (CDC
Cooperative Agreement #U60 CCU 112215, Final Report). Available from the
National Institute for Occupational Safety and Health/Health-Related Energy
Research Branch, Cincinnati, OH, 129 pages.
3.1.14 Follow-Up of Morbidity Study of Bladder Cancer
and Chemical Exposures at K-25, Oak Ridge, Tennessee
Purpose
The purpose of the Follow-Up of Morbidity Study of Bladder Cancer and
Chemical Exposures at K-25, Oak Ridge, Tennessee, is to determine the
risk factors associated with the excess of bladder cancer cases that have
been identified in the K-25 worker cohort.
Background and Agencies Involved
Excess bladder cancer cases have been identified at the Oak Ridge K-25
facility among workers involved in the construction of components for
the gas centrifuge. These workers were previously reported as being at
higher risk for developing bladder cancer, but the exposure assessment
was limited. Since the time of the initial evaluation, additional cases
have been found in the cohort and more extensive workplace monitoring
data have been located. The additional data will allow NIOSH to develop
more precise estimates of exposures for cases within the cohort so that
the magnitude of the risk may be described. Because materials used in
construction of the gas centrifuge are in use across industries, there
would be industry-wide implications. Moreover, the results may indicate
the need for screening and intervention that could provide immediate benefit
to DOE workers.
Time Line
The study has been cancelled.
Status
The study has been cancelled. During initial stages of protocol development
in fiscal year 2000, information was obtained about an existing surveillance
program that was recently put into place at the K-25 facility by PACE/CUNY/University
of Massachusetts at Lowell. This program includes a bladder cancer screening
component. In light of the existence of this screening program, the scope
of this follow-up morbidity study was reviewed and the study was cancelled.
3.1.15 Mortality Among Female Nuclear Weapons Workers
Purpose
Although 80,000 female workers have been employed at DOE facilities over
the years, the fact that there were only small numbers of female workers
at any one facility has limited previous health studies. Female workers
from 12 DOE plants will be combined in this cohort mortality study. Risk
estimates will be developed for exposure to ionizing radiation or to chemical
hazards. This is the only study of women at DOE sites.
Background and Agencies Involved
This study is an all-causes mortality study. It was conducted by the
State University of New York with Dr. Gregg Wilkinson as the principal
researcher, under a grant from the NIOSH Health-Related Energy Research
Branch.
Findings
Among the entire twelve-site pooled cohort, a strong healthy worker effect
was found for all causes of death, including deaths from all cancers combined.
Mortality in the cohort was higher than expected for certain mental disorders,
genitourinary diseases, and ill-defined conditions. The increase for mental
disorders appears to be primarily due to senile and pre-senile dementia.
Among female workers monitored for external radiation, a dose-related
increase in leukemia mortality was observed.
Communication Events
In March 2000, the Health-Related Energy Research Branch released one-page
announcements that the study was nearing completion. In early June 2000,
the Health-Related Energy Research Branch released a one-page summary
of study results. These findings were released to the 12 DOE sites via
fax, e-mail, bulletin board, newsletter, and website communications. The
mass communications effort was successful in targeting an estimated 85,000
current and former workers. In late June 2000, Dr. Wilkinson presented
the study's findings in a live satellite broadcast to the sites. The presentation
was videotaped, and copies were made available to all DOE study site reading
rooms and libraries. Copies of the abstract and the final technical report
are available through the toll-free NIOSH number (1-800-356-4674).
Publication
Wilkinson GS, Trieff, N, Graham, R [2000]. Study of mortality among female
nuclear weapons workers. Buffalo, NY: Department of Social and Preventative
Medicine, School of Medicine and Biomedical Sciences, University of Buffalo,
State University of New York; (DHHS Grant Numbers: 1R01 OHO3274, R01/CCR214546,
R01/CCR61 2934-01, Final Report). Available from the National Institute
for Occupational Safety and Health/Health-Related Energy Research Branch,
Cincinnati, OH, 428 pages.
3.1.16 Study of Heat Stress and Performance in Carpenters
at DOE Sites
Purpose
The Study of Heat Stress and Performance in Carpenters at DOE sSites
will determine if heat stress from the use of protective clothing affects
performance of carpenters and other construction workers in remediation
and hazardous waste work at Hanford and Oak Ridge. Physiologic measures
of heat stress and neurobehavioral performance will be assessed under
actual working conditions.
Background and Agencies Involved
A large amount of work across the DOE weapons complex sites involves
clean-up activities and environmental remediation that require the use
of respirators and full personal protective suits. The findings of this
study, therefore, will be applicable to workers involved in these efforts
across the complex. This study is being performed by the United Brotherhood
of Carpenters Health and Safety Fund, with Dr. Kenneth Rosenman as the
principal researcher, under a grant from the NIOSH Health-Related Energy
Research Branch.
Time Line
The study was expected to be completed in September 2000.
Status
The study received a no cost extension. The final report is scheduled
for submission to NIOSH by the end of December 2000.
- He expects an increased rate of cancer in Oak Ridge and stated that
cancer cases are presenting early and with a more aggressive course.
- He had seen prostate cancer cases with very aggressive growth patterns
in patients of unusually young ages (e.g., 42 years).
- He stated that the cancer best correlated with radiation is acute
leukemia, and that over the last 6 months he has had 3 cases in Oak
Ridge, and the normal rate was 5 per 100,000.
- He noted that there were more cases of lung cancer and colon cancer
than all of the other cancer cases combined. In addition, he noted that
the effect of confounders such as tobacco and diet were not considered,
but if smoking were controlled, the lung cancer rate would be higher
for those with exposure to radioactive elements.
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