| This analytic data file set consists of one file generated for a retrospective cohort mortality study of white males employed at the K-25, X-10, or Y-12 facilities in Oak Ridge, Tennessee JP Watkins, et al. |
| A previous study (Polednak, 1981. Archives of Environmental Health, 57:1-17) of 1,059 white male welders employed between 1943 and 1973 in these three plants compared the mortality experiences of welders employed at K-25, who had potential for nickel oxide exposure, with those employed only at the other sites, who were not exposed to nickel oxides. Based on deaths through 1974, there was an elevated lung cancer SMR of 1.88 for K-25 welders employed for at least 50 weeks, but this was based on only five observed deaths. The current update was based on deaths through 1989 for 1,211 white male welders employed between 1943 and 1985, including the subgroup of 683 K-25 employees with potential for nickel oxide exposure. There were 18,790 person-years of follow-up and 237 deaths for the K-25 subgroup with 15,992 person-years and 226 deaths for the second subgroup employed at the other facilities. Results for the combined cohort showed statistically significant SMRs for lung cancer and prostate cancer. Investigating SMRs separately for the two subgroups, the only statistically significant SMR was for prostate cancer among those welders without potential exposure to nickel oxide, although the prostate cancer SMR for K-25 welders was also elevated. There did not appear to be notable differences between the mortality patterns of the welders with and without potential exposure to nickel oxides. No deaths from nasal sinus cancer were found in either group, and the healthy worker effect was not evident. |
| The single analytic file, ORMULA04_d1 (COHORT), contains a record that includes vital status as of January 1, 1990, for each of the 1,211 members of the cohort. The last SSA submission for this population provided "alive" status as of January 1, 1985; the "alive" category is no longer obtainable from SSA. However, NDI provides a record of all deaths occurring since January 1, 1979. If not identified as deceased by SSA or NDI, individuals last known to be alive before January 1, 1979 were considered lost to follow-up on the last date known alive while those known to be alive after January 1, 1979 were considered alive at the end of the study. There were 463 deaths from all causes with death certificates available for 98.5% of these individuals. |
| Nickel oxide exposure occurred at K-25 when workers welded mild steel pipes that were coated with nickel. These pipes were widely used throughout this facility. Nickel-coated pipes were not used at the other sites. Materials welded at Y-12 and X-10 included mild steel and aluminum. In addition, stainless steel was sometimes used at Y-12. |
