The relationship between airborne concentration of beryllium in the working environment and workers' beryllium lymphocyte transformation test (Be-LTT) values was examined based on data obtained from a four-year survey (1992-1995) conducted at beryllium-copper alloy manufacturing factories. This study showed that the T cells of workers continuously exposed to beryllium of more than 0.01μg/m3 could be activated and that the cell-mediated immune response of workers could be promoted. On the other hand, the Be-LTT of workers exposed to beryllium levels of less than 0.01μg/m3 was shown to be unaffected by beryllium. These findings suggest that beryllium sensitization is not manifested when level of beryllium in working environment are less than 0.01μg/m3. Therefore, in such cases workers do not develop Chronic beryllium disease (CBD). We concluded that the Be-LTT can be applied as a medical indicator to detect the development of CBD.
National Institute of Occupational Safety and Health