The calculation of total transformations in organs following the inhalation of radioactive aerosols of different sizes.

A technique is presented which makes use of the ICRP methodology for calculating the total number of transformations in an organ following the inhalation of radioactive aerosols of various half-lives and activity median aerodynamic diameters (AMADs). As found in studies involving respiratory and gastrointestinal tract activities under similar conditions, there are constants common to the aerosol class which allow the plotting of factors which depend only upon the radioactive half-life of the isotopes involved. The method shows the influence of respiratory uptake on the total number of transformations in the organ as well as the influence of AMAD and the route the isotope takes to the organ, e.g. directly from the respiratory tract or via the gastrointestinal tract. Although the technique is more complicated than that used for the respiratory or gastrointestinal tract uptake, the method requires a minimum of calculation.