RETENTION OF 7Be IN THE LUNGS FOLLOWING INTAKE BY INHALATION.

Several workers were internally exposed to 7Be particles following their dispersion in air from a damaged electrodeposited source. A series of in vivo measurements performed with one worker up to 108 days post exposure determined that retention of 7Be in the thoracic region of the respiratory tract was best described by a two-component exponential function with half-lives of ~0.4 and ~109 days. The initial deposition in the thoracic region was estimated to be 6.8 kBq. The concentration of 7Be in single void urine samples collected from this worker up to 3 days post intake ranged from 1 to 10 Bq/l. In the absence of specific knowledge about the physical and chemical characteristics of the inhaled particles, the committed effective dose was estimated to be 0.3 μSv.