No Detectable Increase in Cancer Mortality in Workers Exposed to Low Doses of Radiation

The Science

DOE’s Low Dose Radiation Research Program has demonstrated that biological responses to high and low doses of radiation are both qualitatively and quantitatively different. These findings suggest it is important to study low-dose exposed populations to understand radiation risks to workers and the public. New analyses were recently completed of mortality data for 46,970 workers—including 5,801 involved in radiation activities—employed from 1948-1999 at Rocketdyne (Atomics International). This worker population is unique in that lifetime occupational doses from all places of employment were sought, updated, and incorporated into the analyses. The workers were followed for up to 60 years. For all cancers excluding leukemia, the relative risk at 100 mSv (10 rads) was estimated to be 0.98 (95% CI 0.82-1.17), and for all leukemia other than CLL, it was 1.06 (95% CI 0.50-2.23). Uranium was the primary radionuclide contributing to internal exposures. This long-term followup has not shown significant excesses of cancers or nonmalignant diseases among the workers studied. Larger combined studies of early workers in the United States using similar methodologies may further refine and clarify radiation risks after protracted exposures.

BER Program Manager

Resham Kulkarni

U.S. Department of Energy, Biological and Environmental Research (SC-33)
Biological Systems Science Division
[email protected]


Boice, J. D., Jr., S. S. Cohen, M. T. Mumma, E. D. Ellis, K. F. Eckerman, R. W. Leggett, B. B. Boecker, A. B. Brill, and B. E. Henderson. 2011. “Updated Mortality Analysis of Radiation Workers at Rocketdyne (Atomics International), 1948-2008,” Radiation Research 176(2), 244-258. DOI: 10.1667/RR2487.1.