A RAPID METHOD FOR MODELING THE KINETICS OF RADIOACTIVE PROGENY APPLIED TO THORIUM IN THE LUNGS

A general method for solving first-order compartmental models (recycli ng and nonrecycling) with any number of radioactive progeny is describ ed and a heuristic proof of the method is provided. The method can be applied to any system where the progeny are assumed to behave isokinet ically with the parent, as is the case with the biokinetic models curr ently recommended by the ICRP. The method is simple to apply, and its application to the modeling of radioactive progeny in the lungs follow ing inhalation of thorium oxides is illustrated. The new ICRP respirat ory tract model is used for this illustration.