Staff Reports
WC Monitor
9/25/2015
A new epidemiological study has concluded that Hanford Site workers with the greatest exposure to the metal beryllium were most likely among personnel there to develop chronic beryllium disease. Those with the disease also were more likely to have worked at Hanford earlier, concluded the study, which was conducted by researchers from National Jewish Health in Denver. The Department of Energy hired the hospital, a leader in respiratory disease research and treatment, after the DOE Hanford Corrective Action Plan in 2010 recommended an epidemiological study. Questions had been raised then about whether Hanford workers were being adequately protected from exposure to beryllium. People with a genetic, allergy-like sensitivity to the metal can develop chronic beryllium disease when they breathe in particles of beryllium that may be too small to see or are exposed through cuts or scrapes. The disease damages the lungs, limiting oxygen that passes into the blood. There may be no symptoms initially, but patients then may develop a dry cough, night sweats, frequent tiredness, and shortness of breath that can become severe.
Hanford began using beryllium in fuel rods to be used in Hanford reactors experimentally in the 1950s and then more widely in the 1960s. End-cap rings for the fuel were composed of a 5 percent beryllium and zinc alloy. They were handled in different ways during production that could have allowed beryllium to be inhaled, including heat treatment, acid cleaning, machining, brazing, welding, and etching, said Dr. Lisa Maier of National Jewish Health. Beryllium use in fuel rods stopped in 1986 at Hanford, but potential for beryllium exposure remained in research labs, in shops where non-sparking tools were customized, and in buildings where beryllium fuel work had previously been conducted and contamination remained. Those included fuel fabrication buildings in the 300 Area, N Reactor buildings where fuel rods were consumed, and buildings where irradiated fuel was processed or held, including the K Basins and the Plutonium Finishing Plant.
The study tied higher numbers of cases of chronic beryllium disease to work at Hanford before 1986 and to more years worked in a building likely to have beryllium contamination. It also linked them to higher scores on a rating system that included being assigned to tasks involving beryllium or to tasks that generated dust that could contain beryllium. Cases in workers hired after 1986 likely were caused by exposure to legacy contamination, the study found.
The percentage of Hanford workers with beryllium sensitization – an immune system reaction to beryllium – that had advanced to chronic beryllium disease was lower than at other DOE sites on which medical studies are available, researchers said. They found about 3 percent of cases progressed annually to chronic beryllium disease among the Hanford workers studied. They also found that the progression of chronic beryllium disease among Hanford workers over time was minimal. Most, but not all, chronic beryllium disease cases studied were in the very early stages.
The study also looked at sarcoidosis, which may have similar symptoms of chronic beryllium disease, but concluded it was a disease distinct from chronic beryllium disease. Sarcoidosis cases were more likely in workers who had outdoor jobs, worked in management, or worked in trades and maintenance. Researchers recommended more study to determine the cause of sarcoidosis, including looking at possible exposure to zirconium and aluminum.
Researchers recommended continued characterization of potential sources of exposure through dust and air sampling. Workers should be vigilant about wearing personal protective equipment, they said. Workers with chronic beryllium disease or beryllium sensitization should have as little further exposure to beryllium as possible. Patients should continue regular medical checks to detect progression of the disease as early as possible. Researchers also recommended that Hanford officials take steps to reduce stress related to diagnosis, including stress from job changes to avoid further beryllium exposure and stress related to medical care. They also suggested genetic studies to learn more about the disease.
The conclusions were based on information for 221 current and former workers who volunteered and completed the study. They encompassed 17 with chronic beryllium disease, 47 with beryllium sensitization, 12 with sarcoidosis, one who did not complete the study, and 146 with none of those conditions who were used as control subjects. Participants were interviewed about their health, their work history, and possible exposure, and their medical records were collected. Researchers said they had hoped to recruit more volunteers. Assessing the exposure to beryllium was more challenging than at other Department of Energy sites, including Rocky Flats in Colorado and Oak Ridge in Tennessee, researchers said. Work histories at Hanford spanned from 1947 to 2013, workers change job titles often, and Hanford is a large site with diverse operations and hundreds of buildings.
