| This analytic data file set consists of a single file generated for a retrospective cohort mortality and morbidity study of all workers throughout the United States who received at least 5 rem (50 mSv) of penetrating ionizing radiation during 1 calendar year before 1979 while employed at DOE nuclear facilities or the U.S. Navy’s Nuclear Reactor Propulsion Plants (NRPPs). The registry of 5 rem workers was assembled between 1979 and 1982 in response to Congressional concern about the long-term health effects on DOE and predecessor agency workers of exceeding the 50 mSv occupational radiation standard for external radiation. Civilian NRPP workers were also eligible for the registry. |
| The study cohort comprised 3,145 persons, including 2,035 DOE workers and 1,010 NRPP personnel from 32 DOE and contractor facilities and 7 naval shipyards. The median length of follow-up was 20 years with approximately 69,000 person-years of follow-up with 76% attributed to white males, 4% to black males, 10% to “other” males (race not determinable), 10% to those of undeterminable race and gender, and the remaining less than 1% to females. |
| The total population external radiation dose through 1978 was 718.0 Sv (85% to white males) with a median of 153.4 and a range of 50.0 to 44,010.0 mSv. The median year of hire at the facility of first 50 or more mSv per year exposure (FF50) was 1954, with median length of employment at FF50 being 14 years. Median hire age at FF50 was 27 years, while first yearly exposure to at least 50 mSv occurred at a median age of 33. Approximately two-thirds of the cohort was retired or terminated before 1979. DOE workers comprised 96.4% of those entering the registry from 1943 through 1959 but only 33% of those entering from 1960 through 1978. More than 80% of the cohort received a 50 mSv or greater exposure in only 1 year. |
| The analytic file, MFF94A02_d1, contains a record for each of the 3,145 cohort members. This file contains demographic, work history, facility, vital status as of December 31, 1984, and exposure information. Vital status was obtained for 86.6% of the population, with 588 identified as deceased. Cause of death (ICDA8) was certified by 96.3% of these and included 159 cancers (127 for white males). The analytic file doses for each study member are reported in rem. A cumulative dose of 500 mSv (50 rem) or more was acquired by 147 members of the cohort. The standardized mortality ratio for white males was .88 (95% CI = .80-.97) for all causes, 109 (95% CI = .90-1.29) for all cancers, and 1.15 (95% CI = .61-1.97) for all lymphoma and hematopoietic cancers. |
| The DOE workers had been involved from 1947 through 1978 in research, development, and production operations with potential exposure to external and internal radiation, as well as to industrial chemicals, depending on the facility of employment and the time period. Non-radiologic hazards included organic solvents, cutting oils, asbestos, and toxic metals, such as uranium, lead, cadmium, nickel, mercury, and beryllium. The NRPP workers had higher potential for radiation and chemical exposures starting in the 1960s during overhauling and refitting of nuclear vessels, with cobalt-60 as a primary source of external radiation. |