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Findings from the NIOSH-funded Savannah River Site mortality study.

NIOSH 2008 Apr; :1-3
Why was this study done? Employees at the Savannah River Site worked with a number of hazardous agents, including ionizing radiation and asbestos. The National Institute for Occupational Safety and Health (NIOSH) is a federal agency that works to improve the health and safety of America's workers. NIOSH provided funding to researchers from the University of North Carolina to find out if working with hazardous agents may have led to more deaths at the Savannah River Site than would be expected in the general population. Though researchers did not estimate exposures to all hazardous agents at the Site, they did look more closely at exposure to ionizing radiation in workers who died from leukemia. This was done to see if radiation exposure may or may not be associated with death from leukemia. Who was included in the study? People employed by the DuPont Corporation, who worked at the Savannah River Site between 1950 and 1986, were included in this study. These 18,883 workers were employed for at least 90 days at the Savannah River Site, worked in operations, and had not worked for any other Department of Energy facility. How was the study done? Government records were used to find out how many of the 18,883 workers had died, and what were the causes of death. The records used (e.g., death certificates) did not provide any medical information other than cause of death. From these records, researchers determined the number of workers that died from each cause of death and compared this to the number of deaths that would be expected in the U.S. general population and in the South Carolina general population. Using radiation exposure records, researchers were also able to get information on recorded radiation doses for individual workers. Radiation doses of the workers who died from leukemia were then compared to radiation doses of a sample of workers who were still alive at that time. From this comparison, researchers were able to examine the possible link between leukemia death and recorded radiation doses. This is called the "dose-response" relation. This study only examined radiation doses from external exposures to ionizing radiation and internal exposures to tritium (tritium that was inhaled, ingested, or absorbed through the skin). Researchers did not estimate workers' doses from other radionuclides that may have been inhaled, ingested, or absorbed. Researchers also did not estimate exposures to other hazardous agents. What did the researchers find? Overall, researchers found the death rates for workers at the Savannah River Site were generally lower than U.S. death rates. However, more male workers at the Site died from pleural cancer and from leukemia than would be expected in the general population (information about these two types of cancer can be found in the "Additional Information" section). Researchers found that the higher the recorded radiation dose, the higher the chance of fatal leukemia. The chance of fatal leukemia was 25% higher in workers exposed to one rem of radiation, though this risk was found to lessen 15 years after the exposure. What does this mean? This study suggests that compared to the general population, Savannah River Site workers have a higher chance of dying from pleural cancer, a disease often linked to asbestos exposure. This study also suggests that for 15 years after exposure to radiation at the Site, workers have a higher chance of dying from leukemia than if they were not exposed. Leukemia is a rare disease, which means that if a person were exposed to one rem of radiation it is still unlikely that they will get leukemia. At the Savannah River Site, asbestos and radiation exposures are generally lower today than during the years of operation covered by this study. What should you do? If you currently work with radioactive materials or non-radioactive hazardous materials, contact your health and safety representative or employer if you have questions on how to best protect yourself from exposure. Share this information with your doctor if you are concerned about your health or have questions about these illnesses.
Nuclear-power-plants; Cancer; Cancer-rates; Occupational-diseases; Mortality-data; Mortality-rates; Asbestos-dust; Ionizing-radiation; Men; Women; Epidemiology; Statistical-analysis; Region-4; Leukemogenesis; Lung-cancer; Pleural-cavity; Kidney-disorders; Skin-cancer; Nuclear-radiation; Nuclear-energy; Nuclear-hazards
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NIOSH Division
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National Institute for Occupational Safety and Health
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division