Study: Higher cancer rates for Hanford workers

Former Hanford construction workers have an increased risk of death from a blood cancer linked to radiation and another cancer linked to asbestos, according to a new study. The study published in the September issue of the American Journal of Industrial Medicine drew on data collected in the Building Trades National Medical Screening Program for Hanford and three other Department of Energy sites. “While several studies have investigated mortality risks among (Department of Energy) production workers, little data exist concerning mortality among construction and trade workers,” the study said. It looked at 8,976 workers who had participated in the building trades screening program at the four sites and had an initial screening interview from 1998 through 2004. Those interviews were compared to the National Death Index, which had information only through 2004 when the study began. About 31 percent of the people in the study – 2,779 workers – had done construction work at Hanford, and 94 of the 266 Hanford workers who had died had died of cancer. That is 14 more cancer deaths than would be expected in the general U.S. population, said Knut Ringen of Stoneturn Consultants in Seattle, one of the authors of the study. He also is the principal investigator for the Building Trades National Medical Screening Program. “The most significant finding at Hanford was a very high rate of mesothelioma,” Ringen said. That’s 11 times more than expected in the general population. Mesothelioma is a cancer of the lungs and lining of the stomach strongly tied to asbestos exposure, he said. Those cancer deaths were in addition to deaths from asbestosis, a noncancerous lung disease caused by inhaling asbestos fibers. The deaths from asbestosis were 30 times that of the general population, which is unlikely to have the disease, he said. Unlike workers at the other sites in the study – the DOE sites at Savannah River, S.C.; Oak Ridge, Tenn., and Amchitka, Alaska – Hanford workers also had an elevated risk of multiple myeloma. Multiple myeloma is a cancer of plasma cells, a type of white blood cell formed in bone marrow. Deaths of multiple myeloma were three times that of the general population and could be linked to workplace radiation exposure, Ringen said. Excess risk for multiple myeloma has not typically been observed for construction workers, but it has been observed in studies of other DOE site workers, the study said. Hanford’s past records of construction workers’ exposure to radiation are unreliable, Ringen said. Many worked for subcontractors, and they tended to work at Hanford when needed and then take other jobs in the Mid-Columbia until they were needed at Hanford again. In addition, construction workers were called to work in times of crisis, such as leaks that required retrofitting or repairs, for which records would more likely have been secret, he said. The study also found more deaths than typical from cancers of the trachea, bronchus and lungs among Hanford workers, Ringen said. However, there were not enough of those deaths to be considered statistically significant, or to make sure that the data indicated a true trend. Other sites also had death rates for some diseases that were higher than the remainder of the sites. At Oak Ridge non-Hodgkins lymphoma deaths were high and at Savannah River chronic obstructive pulmonary disease death rates were high. Information from studies done with data from the Building Trades National Medical Screening Program is made available to DOE officials to continue improving safety at Hanford and other sites, Ringen said. The exposures that may have caused the cancers of the workers in the study likely occurred 20 to 30 years ago, and safety and health protection of workers has improved since then, he said. The study found that the elevated risk for mesothelioma and asbestosis was confined to workers first employed before 1980. The average age of construction workers volunteering for screening nationwide in the program is about 60. The screening program continues to provide free health screenings to Hanford construction workers. Workers complete a work history interview and a limited medical screening exam to identify risk factors for diseases that might develop in the future. They receive information on ways to reduce risk, and data collected in the program may help protect workers in the future. For more information about the program, call Sherry Gosseen at 783-6830 or (800) 866-9663, or go to www.btmed.org. Hanford workers or their survivors who developed illnesses caused by workplace exposure also may be eligible for compensation throught the Energy Employees Occupational Illness Compensation Program. Call 946-3333 or (888) 654-0014 for information. The study is the Mortality of Older Construction and Craft Workers Employed at Department of Energy (DOE) Sites. The primary author of the study was John Dement of Duke University Medical Center in North Carolina.