Abstract
A method is presented for graphically determining the total number of nuclear transformations in the lung of an individual who inhales a radioactive aerosol. Knowing the AMAD, the inhalation class and the half-life of the radioisotope, the number of transformations which occur in the respiratory system per second for a concentration of 1 Bq/m3 may be taken from a graph. This may be corrected for the actual concentration and for the time of the inhalation exposure.