Researchers' findings could help ease concerns about uranium workers' health
University of Louisville researchers and their colleagues have found that the death rates from all causes and cancer in general among workers at a Kentucky gaseous diffusion plant are significantly lower than those among the overall U.S. population for the same time period.
Researchers from the UofL School of Public Health and Information Sciences, the University of Cincinnati and the University of Kentucky conducted a five-year study of workers at the Paducah Gaseous Diffusion Plant (PGDP) in response to concern about past and present radiation and chemical exposures.
PGDP, located in western Kentucky, is the only operating uranium enrichment facility in the United States. Two other plants existed in Oak Ridge, Tenn., and Piketon, Ohio.
The Paducah plant was commissioned in 1952 under the U.S. Department of Energy as part of a U.S. government program to produce enriched uranium for military reactors and nuclear weapons, but its mission changed in the 1960s to one of enriching uranium for use in commercial nuclear reactors to generate electricity.
Exposure to radiation and chemicals have been linked to cancers. Studies had been conducted for the other two gaseous diffusion plants, but none had been conducted for PGDP.
“This was an important study, because it addressed lingering concerns about the health of workers at the (plant),” said David Tollerud, UofL professor of environmental and occupational health sciences and principal investigator for the study.
“It is important for occupational health and public health research to attempt to answer pressing concerns of impacted populations, and we were able to report that we didn’t find unexpectedly high rates of disease in this workforce,” he said.
Researchers compiled data from employees' work history, demographic records and records from the U.S. Social Security Administration, the National Death Index and individual state departments. They found complete data for 6,759 or the 6,820 employees who worked at the plant at least 30 days between September 1952 and December 2003.
Out of those 6,759 people, the researchers identified 1,638 deaths. This is fewer than the 2,253 deaths that would have been expected in the general public. They also found that 461 of the deaths were attributed to cancer. From a comparable sized group in the general public, they would have expected that number to be 592.
Two groups had higher death rates over their fellow employees, however. When analyzing the worker data by job classification, they found that security workers had higher overall death rates than other employees, while chemical operators had higher death rates from leukemia and multiple myeloma than the rest of the workers.
“The increased number of lymphatic and bone marrow cancer deaths is consistent with what we expected. Based on other studies, these forms of cancer have been linked to low levels of radiation exposure,” Tollerud said.
The National Institute for Occupational Safety and Health funded the study; efforts by U.S. Sen. Mitch McConnell (R-Ky), helped get it off the ground.
The research team plans to present its findings to PGDP workers. It also plans to distribute a study fact sheet that summarizes the main findings and directs workers to resources that are available if they have concerns or questions.
The study, titled “Mortality among PGDP workers,” was published in the July 2010 edition of the Journal of Occupational and Environmental Medicine.