| This analytic data file set consists of six files generated for a retrospective cohort mortality study of all workers employed at the K-25, X-10, or Y-12 facilities in Oak Ridge, Tennessee, who were hired before January 1, 1983 and employed for at least 30 days Ed Frome, et al. |
| Results of this study were published in Applied Occupational and Environmental Hygiene and Radiation Research in 1997. |
| This study, an update of a previous study by Frome (data file set ORMULA02), is based on deaths through 1984 for 106,020 workers of both genders. There were 2,810,000 person-years of follow-up with 65% from white males, 30% from white females, 3% from non-white males, and 2% from non-white females. The study involved three stages of analysis. First, SMRs were calculated for each of the four race/gender groups for a series of causes of death. Next, a comparison of mortality among the facilities for selected causes of death was conducted by race/gender group. Finally, a dose-response analysis for cumulative external dose was carried out for white male employees from Y-12 after mid-1947 and X-10. |
| A previous study (Frome, et al. 1990 Radiation Research 123: 138-152) of 28,008 white males employed between 1943 and 1947 at these three sites evaluated the influence of the ever/never radiation exposure status along with duration of employment, facility, socioeconomic status, birth year, and period of follow-up, on cause-specific mortality. Based on deaths through 1980, there was an elevated SMR of 1.11 for all causes of death with a significant upward trend of 0.74% per year. The excess mortality was due primarily to lung cancer and diseases of the respiratory system. However, the increase was found to be related to socioeconomic status rather than radiation exposure status. |
| The analytic file, ORMULA05_d1 (DEMGR), contains a record for each of the 118,588 workers hired by one of the Oak Ridge facilities before January 1, 1983. For the study cohort 12,568 were eliminated from this group, including 11,002 who were employed for fewer than 30 days and the remainder who had "critical errors" in their data. This file contains demographic, work history, and vital status information as of December 31, 1984. Of the 27,982 deaths, 22,724 were white males. There are three exposure files ORMULA05_d2, ORMULA05_d4, and ORMULA05_d6 (K25EXP, X10EXP, and Y12EXP respectively) that contain, for the designated facility, annual unadjusted external radiation doses, annual indicator variables for internal radiation exposure, and annual flags that specify employment in that facility during the year. White males received 93% of the annual recorded doses, which totaled 405.5 sieverts (Sv). There are two additional exposure files. Annual adjusted doses for X-10 are contained in ORMULA05_d5 (X10ADJ), along with data used to compute these values, including annual values for days worked, department, and type of adjustment. Doses through 1956 were adjusted upward to compensate for potential bias in recorded doses due to monitoring policies and practices at X-10 during early years of plant operation. Early Y-12 doses were adjusted because of the large number of nonmonitored person-years at Y-12 through 1960. The adjusted dose file for Y-12, ORMULA05_d5 (Y12ADJ), contains annual adjusted doses as well as flags to specify type of adjustment. |
| ORNL began operation at X-10 early in 1943 as a research and development facility. Potential exposures to X-10 employees included external radiation, a variety of radionuclides, lead, beryllium, and chemicals associated with a research and development laboratory. From 1943 through mid-1947, Y-12 produced enriched uranium by the electromagnetic separation process and was operated by TEC. Potential exposures at Y-12 included uranium dust, some external radiation, and variety of chemicals, including solvents and lubricants. After mid-1947, Y-12 was managed by Union Carbide Corporation Nuclear Division and changed operations to nuclear materials fabrication. At that time, potential exposures expanded to include metals and asbestos. K-25 began in 1945 to produce enriched uranium using a gaseous diffusion process. Uranium dust was a potential exposure at K-25 along with some external radiation exposure, uranium compounds, metals, solvents, and chemicals. |
