Conducting
public health activities at Department of Energy
(DOE) sites is the responsibility of two groups in
the Centers for Disease Control and Prevention (CDC):
National Institute
for Occupational Safety and Health (NIOSH)
The
National Institute for Occupational Safety and
Health (NIOSH) has a broad program of occupational
health research across the DOE complex. NIOSH interacts
with DOE and DOE workers in three ways.
NIOSH Studies on the Health of Oak Ridge Workers
Researchers at NIOSH, in collaboration with others,
have conducted numerous studies of health effects
among workers at the Oak Ridge Reservation. Findings
of the studies include the following :
- Mortality Among Workers
at Oak Ridge National Laboratory
The Oak Ridge National Laboratory (X-10) has been the subject of long-term
epidemiologic study. A mortality analysis of 8,375 white males through 1977
found no cause of death that was higher than expected based on the U.S. general
population. However, leukemia mortality was related to length of employment
in engineering and maintenance jobs. A follow-up study reported that the
death rate from leukemia through 1984 was greater than the U.S. rate, particularly
among workers monitored for internal radiation contamination.
A positive trend was reported for all cancers combined by level of cumulative
external dose but not for leukemia. In the most recent study of deaths through
1990, none of the rates for the four causes of death reported, all causes
of death combined, all cancers combined, lung cancer, and leukemia, was higher
than the corresponding U.S. rates.
A recent study of deaths through 1990 reported that radiation doses received
after age 45 years strongly predict the all cancers combined mortality rate;
an earlier X-10 study noted that employees age 65 years and older at exposure
were at higher risk.
- Mortality of Workers at
a Nuclear Materials Production Plant at Oak Ridge
(Y-12)
The first study of Y-12 workers included 18,869 white males who ever worked
at the plant and mortality through 1974 was identified. The second study
was restricted to 6,781 men who worked at least 30 days with mortality through
1979. A third study was expanded to include 10,597 nonwhite workers and females
with deaths through 1990. The death rate from lung cancer was higher than
the U.S. rate in the most recent two studies. Analysis of deaths through
1979 did not confirm positive trends for any cause of death with either external
or internal exposure to ionizing radiation although a weak trend was observed
for lung cancer.
During the early operation of the Y-12 plant from 1942-1947, a group of 694
male workers was exposed to phosgene gas on a chronic basis and 106 males
and 91 females received acute exposures. 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 with particular interest in respiratory diseases and lung cancer. There
was no evidence for increased mortality from respiratory diseases in this
group.
- Mercury Workers Health
Studies
Between 1953 and 1963 the Y-12 Plant used metallic
mercury in a process to produce large quantities
of enriched lithium. There were 5,663 workers categorized
by exposure based on results of urinalysis data.
Analysis of deaths through 1978 revealed no differences
in the mortality patterns for mercury exposed workers
as a whole, workers with the highest mercury exposures,
and workers employed more than a year in a mercury
process. A total of 502 mercury workers were also
involved in a clinical neurology study. Clinical
measurements revealed some deficiencies in neurological
function particularly among those workers with
the highest exposures, but these were not associated
with the duration of exposure. A follow up study
of 219 of the original subjects in the 1990s revealed
that some neurologic effects were still detectable.
- Morbidity and Mortality
Among Workers Employed at a Uranium Gaseous Diffusion
Facility at Oak Ridge (K-25)
Studies of workers at K-25 found that white males had high rates relative
to the U.S. general population for all causes of death; cancer of the respiratory
system, particularly lung cancer; bone cancer; mental disorders; all respiratory
diseases, particularly pneumonia; symptoms, senility, and ill-defined conditions;
all external causes of death, particularly accidents and specifically motor
vehicle accidents. White females had a high rate for symptoms senility, and
ill-defined conditions.
Powdered nickel was used at K-25 to produce the barrier material that separates
and enriches uranium. Death rates for 814 nickel workers who made the barriers
were compared to 1,600 controls. No differences in the death rates for the
exposed and non-exposed workers by cause of death through 1972 were detected.
A later study compared the mortality of the 814 nickel workers through 1977
and 7,552 non-exposed workers. There were no causes of death with a rate
higher than the U.S. rate and no differences between exposed and non-exposed
workers.
- Follow-Up of Morbidity
Study of Bladder Cancer and Chemical Exposures at K-25,
Oak Ridge, Tennessee
Epoxy resins and solvents were common exposures among
K-25 gas centrifuge workers. In Phase I of a study of
centrifuge workers, 263 workers with the most exposure
were compared with 271 workers with no exposure at the
plant during the same period. The centrifuge process workers
reported five bladder cancers versus none reported by
the non-centrifuge group. The standardized incidence rate
ratio was 7.8 for process workers versus comparison workers.
In Phase II of the study, a larger group, who had lower
levels of exposure to the centrifuge process, was studied.
One additional case was found in a centrifuge worker and
two additional cases were found in maintenance workers
who were assigned to work in centrifuge areas. An equal
number of cases of bladder cancer were found in the comparison
group in Phase II. A specific cause for the increase in
bladder cancer was not identified.
- Studies of Combined Oak
Ridge Facilities (Tennessee Eastman Corporation,
Y-12, X-10, K-25)
Several studies have considered all ORR workers, the most recent one updated
mortality through 1984. Mortality from all causes of death combined and all
cancers combined were similar to overall U.S. rates. There were substantial
differences in death rates among workers at the various ORR plants, particularly
the rates for lung cancer, leukemia and other lymphatic cancer. Within the
second study, data for 28,374 workers at X-10 and Y-12 were analyzed and
positive trends were reported with increasing external radiation dose for
all causes of death combined and all cancers combined.
Three studies of brain cancer across the four ORR facilities have been published.
The exposure analysis of 26 chemicals found that none were positively associated
with brain cancer. No positive trends for brain cancer were found with increasing
external radiation dose and internal dose as measured by the lung dose Although
workers with brain cancer were more likely than other workers to have worked
at ORR more than 20 years, there was no trend of increasing cancer with the
number of years worked.
Mortality data through 1974 and through 1989 were analyzed for about 1,059
white male welders at ORR. No death rates were higher than the U.S. rate
through 1974. When deaths through 1989 were considered, welders bad higher
rates of lung cancer, cancer of the prostate, and gastric ulcers. The risk
of each cause was different among the facilities. The risk of lung cancer
among welders exposed to nickel oxides did not differ from non-exposed welders.
- Multi-Site Multiple Myeloma
Case-Control Study
A multi-site study of multiple myeloma deaths included workers from X-10.
Although the death rate was not higher than expected, higher risks were encountered
by workers whose radiation exposures occurred after age 45.
- Childhood Leukemia Case-Control
Study
A study of the potential association between paternal
exposure to ionizing radiation and risk of childhood
cancer found no link between leukemia and paternal
employment at ORR. Children whose fathers worked
at the Hanford Nuclear Reservation were more likely
to get CNS (central nervous system) cancer than
children whose fathers worked at other sites, including
ORR, but this finding was based on small numbers
and was not statistically significant.
- Cyanide Health Hazard
Evaluation at K-25
A NIOSH health hazard evaluation, requested by
K-25 site employees, investigated possible worker
exposure to cyanides. The 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 Oak Ridge National Laboratory, sponsored
by a NIOSH grant, investigated statistical estimation
of dose from daily and weekly dosimetry data for
ORR radiation workers included in previous epidemiologic
studies. The study found that diferences between
the two methods were substantial, and recommended
methods of reducing uncertainly for some estimates.
- Improved Systems for
Worker Exposure Surveillance
The Oak Ridge Associated Universities, under a NIOSH grant, developed a project
at ORR to develop a system for the prioritization of industrial hygiene and
medical surveillance efforts. The Worker Exposure Surveillance System (WESS)
was designed for easy data merger with traditional occupational health systems
utilizing environmental level analyses, occupational titles, and area descriptors.
- Work Histories Evaluating
New Participatory Methods
Exposure History for the Construction Trades (WHEP). The University of Cincinnati,
under a NIOSH grant, created an exposure history for the construction trades
at ORR, which was aimed at improving worker recall of complex occupational
exposures across a large number of short-term workplace assignments. New
techniques were used to establish guidelines and formats for personal work
histories. This study has recently been completed and the results will be
published in 2001.
- Exposure Assessment of
Hazardous Waste, Decontamination and Decommissioning,
and Clean-up Workers----Phase I Feasibility Study
Exposure assessment of hazardous waste, decontamination and decommissioning,
cleanup workers (HAWW). Feasibility studies at seven DOE sites, including
ORR, determined that the availability of records to identify workers and
their primary activities, exposures, work histories, and medical information
varied significantly from site to site. The necessary information to conduct
exposure assessment, hazard surveillance, or epidemiology studies of remediation
workers is currently not readily available. Within sites, data systems are
fragmented and data management is inconsistent in the current environment
of decentralized management and increased subcontracting.
- Prevention of Stress
and Health Consequences of Downsizing and Reorganization
Prevention of stress and health consequences of downsizing (STDN). The effects
of downsizing on organizational climate, worker health, and performance were
studied at several DOE sites, including ORR. Data gathering included interviews,
workplace observations, employee discussion groups, an employee survey distributed
to more than 10,500 employees, and a historical record review. Researchers
identified opportunities to reduce job stress that could lead to improved
employee health and organizational well-being. Suggested intervention strategies
were proposed for further research.
- Mortality Among Female
Nuclear Weapons Workers
Study of mortality among female nuclear workers (MAFN). A study of female
workers from 12 DOE plants, including ORR, was combined in a cohort mortality
study, and risk estimates were developed for exposure to ionizing radiation
or to chemical hazards. For the entire pooled cohort, mortality from mental
disorders, diseases of the genitourinary system, and from ill-defined conditions
was higher than expected. External ionizing radiation exposure in these workers
appeared to be associated with increased relative risk for leukemia and,
to a lesser degree, associated with increased relative risks for all cancers
combined and for breast cancer.
- Multiple Myeloma Case-Control
Study at K-25 Plant
DOE's epidemiologic surveillence assess the overall health of the current DOE
work force at 14 DOE sites, including ORR (Y-12), Oak Ridge National Laboratory
(X-10), and East Tennessee Technology Park (K-25). The goal is to identify
groups of workers that may be at increased risk for occupation-related injuries.
- Cohort Mortality Study
of DOE Chemical Laboratory Workers
An indendent panel of nationally recognized occupational health physicians
is conducting individual medical evaluations to assess occupational health
complaints and symptoms of 53 current an former Lockheed Martin Energy Systems
workers at the East Tennessee Technology Park (formerly called the K-25 site).
These medical evaluations include reviews of prior health studies; visits
to workers' workplaces and surroundings; work history interviews with individual
workers; reviews of worker medical records; physical examinations; and sepcialized
follow-up inquiries and testing.
- The DOE Beryllium Worker Medical Surveillance
Program, which includes an intensive, coordinated
health-risk communication effort, is designed to
detect and diagnose chronic beryllium (CBD) among
current and former workers exposed to beryllium
throughout the DOE complex, including ORR. Information
from this program is used to improve and evaluate
worker protection and control measures, to monitor
trends in CBD frequency, and to strengthen work
planning to minimize worker exposures.
- DOE's Former Worker Program is a pilot program
designed to provide medical surveillance for selected
former DOE workers at risk of work-related illness
as a result of exposures while working at DOE facilities.
The following projects are underway at ORR:
- The former construction worders project is led by Dr. Eula Bingham
of the University of Cincinnati in cooperation with the United Brotherhood
of Carpenters Health and Safety Fund, the Center to Protect Workers'
Rights, and Duke University Medical Center. The Phase I assessment identified
approximately 800 former construction workers. Phase II will focus on
medical screening of workers exposed to asbestos, beryllium, noise, silica,
solvents, and heavy metals.
- The project involving former production workers from the Oak Ridge
K-25, Paducah, and Portsmouth gaseous diffusion plants is led by Dr.
Steven Markowitz of Queens College, City University of New York, and
Mr. Robert Wages of the Oil, Chemical, and Atomic Workers International
Union, in cooperation with the University of Massachussetts at Lowell.
The Phase I assessment identified approximately 1,260 former production
workers as potentially at high risk. Phase II will focus on medical screening
of workers exposed to asbestos, beryllium, bladder carcinogens, chlorinated
solvents, flourine compounds, nickel, noise, silica, uranium, welding
fumes, and heavy metals.
- DOE plans to expand the Former Worker Medical
Surveillance Program to Current workers and additional
former workers at the three gaseous diffusion plants.
National Center for
Environmental Health (NCEH)
The
National Center for Environmental Health (NCEH) conducts
environmental dose reconstructions, radiation epidemiology
studies, and radiation risk analysis and communication
at DOE sites.
Community Health Investigations and Activities
The NCEH conducted the following health strategies
to evaluate reported illnesses afflicting residents
in communities surrounding the Oak Ridge Reservation.
In 1983 the Tennessee Department of Health and Environment
and the Centers for Disease Control and Prevention's
(CDC) National Center for Environmental Health (NCEH)
conducted a pilot survey in
Oak Ridge in response to community concerns about
mercury contamination in the East Fork Poplar Creek
flood plain and the sewer line beltway. The pilot
survey concluded that residents and workers in Oak
Ridge are not likely to be at increased risk for
having significantly high mercury levels. Mercury
concentrations in hair and urine samples were below
levels associated with known health effects.
In 1993 ATSDR and CDC facilitated laboratory
support from the National Center for Environmental
Health at CDC for clinical evalautions of selected
patients who had been referred to Howard Frumkin,
MD, DrPH, of the Emory University School of Public
Health. Dr. Frumkin conducted individual clinical
evaluations of the Oak Ridge physicians patients
and did not report any hazardous substance exposure
to public health agencies
According to the 1998 CDC
health investigation of the Scarboro community,
the results of the self-reporting health survey
indicated elevated rates of asthma and wheezing.
The asthma rate was 13% among children in Scarboro,
compared to national estimates of 7% among all
children aged 0-18 years, and 9% among African
American children aged 0-18 years, which is less
that the 14.5% Chicago rate. The wheezing rate
among children in Scarboro was 35%, compared to
international estimates of 1.6% to 36.8%.
No statistically significant association was found
between exposure to common environmental triggers
of asthma (e.g., tobacco smoke, pests, unvented gas
stoves, and dogs or cats in the home) or potential
occupational exposures (e.g., living with an adult
who works at ORR or living with an adult who works
with dust and fumes and brings exposed clothes home)
and asthma or wheezing illness.
The physical examinations of 23 Scarboro children
who were identified in the survey as possibly having
asthma indicated that all were generally healthy
and no urgent health problems were identified. Only
one child had a lower respiratory illness, and none
were wheezing at the time of the physical examination.
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