Abstract
Thorium distribution and excretion patterns following a single inhalation exposure to a thorium citrate complex aerosol were similar to those observed following exposure to a thorium chloride aerosol except that the initial absorption of thorium from the lungs in the former case was approximately twice that in the latter. Results from multiple exposures to thorium chloride aerosols indicated that the inhaled thorium in animals exposed 2 to 5 times behaved in a manner similar to those exposed only once. These results are discussed in relation to thorium MPC, calculations.
