Distribution of 241Am in the human body as determined by external counting

Methods for determining the distribution of 241Am within the body of a contaminated subject and their application to several cases under study at the Center for Human Radiobiology are described. In general, 241Am is found in the lungs even after long periods of time since inhalation, and systemic 241Am is observed to be deposited in the liver and to label the skeleton in a fairly uniform manner; similar findings have been reported in animal studies (L172). Further analysis of the skeletal distribution of 241Am indicates deposition on bone surfaces. In contrast, the distribution of injected 239Pu in an (abnormal) skeleton is nonuniform when compared to that of 241Am