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.

1. He expects an increased rate of cancer in Oak Ridge and stated that cancer cases are presenting early and with a more aggressive course.
2. He had seen prostate cancer cases with very aggressive growth patterns in patients of unusually young ages (e.g., 42 years).
3. 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.
4. 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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