Application of beryllium antibodies in risk assessment and health surveillance: two case studies

This paper demonstrates that current standards used by the Occupational Safety and Health Administration (OSHA) to establish an area free from potential beryllium contamination may be inadequate. Using the Beryllium Antibody Assay, it was shown that workers exposed to former beryllium work areas, thought to be sanitized and to meet OSHA standards, experienced statistically significant rises in blood beryllium antibody titers. This finding raises the question of whether the equipment currently required to protect workers in beryllium-laden environments is sufficient. The project mission of decommissioning/decontaminating the former nuclear weapons plant at Rocky Flats Environmental Technology Site (RFETS), instituted in 1992, has necessitated development of new technology directed toward safe and responsible cleanup. Challenges have been posed not only by the need to dispose of radioactive and chemical waste, but also by the problem of cleaning up hazardous metals such as the element beryllium. Beryllium was used extensively in research and the manufacture of nuclear weapons components at Rocky Flats for over 40 years. Since inhalation of this element can induce chronic beryllium disease (Eisenbud and Lisson, 1983), an antibody assay was developed to screen workers for internal exposure to beryllium. Exposure is indicated by a titer of antibodies greater than two standard deviations above a normal population control (defined as the mean titer of pooled samples from 51 individuals with no known exposure to beryllium) and a p-value of < 0.05. This paper describes two new applications for the assay: risk assessment and health surveillance. Case study 1 involves a team of three workers who cleaned a beryllium plenum and whose beryllium antibody titers provided a quantitative assessment of their exposure. Case study 2 describes the use of the antibody assay to determine the probable manner in which one worker was exposed to beryllium while performing his duties as an architectural engineer.