A cohort mortality study of workers was conducted to test for an association between mortality and employment at the Mound Plant. The study examined differences in mortality for workers at the plant during its polonium-210 era (1943-1959) and for its plutonium-238 era (1960-1980) by computing period- specific standardized mortality ratios (SMRs) based on U.S. rates. The analysis focused on 4,697 white and presumed white males who were employed between April 1, 1942, and December 31, 1979, at the Mound Plant. SMRs of 96 were observed for both all causes and for all cancers for the study period (1943-1979). No SMR was significantly greater than 100 for these workers. A significantly elevated SMR for lung cancer (SMR = 204, 90% CI = 140, 290) was observed for workers employed during World War II (1943- 1945). Similar results were noted for all causes of death, all cancers, cancers of the rectum, nonmalignant respiratory diseases, and all injuries during this time period. SMRs for these causes of death during the polonium era, but after World War II, were not elevated. No elevated SMRs were observed during the plutonium era. A very strong healthy worker effect was observed for workers in the plutonium era, although the length of follow-up for these workers was relatively short.
The single analytic file (ANFILE) in this data set contains demographic and vital status data for 4,697 white males and presumed white males who were employed between April 1, 1942, and December 31, 1979. Not included in the analytic file are workers employed less than 30 days during this period, workers with unknown birth dates, and workers with both unknown hire and termination dates. No exposure data are included in the file.
Vital status was determined for 97.6% (4,588) of the workers in this file. Death certificates were obtained for 97% (803) of the known deaths.
The Mound Plant has been a center for the separation, chemistry, and metallurgy of polonium-210 and processing of plutonium-238 for heat sources. Other small research projects involved radium and thorium. Workers could have been exposed to external and internal sources of radiation; however, this analysis did not examine exposure data.
END_STDY Vital status follow-up through 12/31/79 is about 98%.
ENDPOINT Mortality.
EXPOSURE (exposure agent/type/measurement method): Exposure assessed by calendar period of work and duration of work.