In vitro solubility of ⁷Be particles released from a damaged source

The solubility of ⁷Be particles was measured in vitro as part of an evaluation of the exposure of workers who inhaled particles released from a damaged source. Initial in vivo measurements performed with one worker revealed that a significant fraction of ⁷Be particles were rapidly removed from the respiratory tract with a half-life of approximately 0.4 days. Since rapid clearance of ⁷Be was not supported by conventional biokinetic models, a study of the solubility of the particles in vitro was launched. A representative sample of the ⁷Be particles was collected from the damaged source and exposed to a surrogate lung fluid solution for increasing periods of time. Over 98% of the material was dissolved at the end of the dissolution period. The effective half-time for solubility of the majority of ⁷Be particles was found to be ≅ 0.4 days and is wholly consistent with results of in vivo measurements. (author)