LUNG DEPOSITION IN RODENTS DURING EXPOSURE TO ATTACHED RADON PROGENY

Tumour induction has been studied in rodents exposed to radon and its progeny with potential alpha energy concentrations ranging from 600 to 1800 working levels (WL). As part of these studies, the deposition of short-lived radon progeny (Po-218, Pb-214, and Bi-214) in the lung ha s been measured in a sample of exposed animals. Exposure conditions we re monitored continuously including individual radon progeny concentra tions and the 'unattached' fractions of Po-218 and PAEC. Following exp osures under similar conditions of aerosol size (0.15 mu m count media n diameter) and low 'unattached' fraction (<1.5%), it has been possibl e to establish a relationship between activity deposited in lung and t he potential alpha energy concentration. These data have also allowed the estimation of the absorbed alpha dose to the lungs of the exposed animals. This will allow comparison with the biological effects observ ed during the lifespan study. Copyright 1996 Elsevier Science Ltd.