Executive Summary 1989

This report summarizes the primary scientific activities of the United States Transuranium and Uranium Registries for the period October 1, 1988 through September 30, 1989. The Registries are parallel human tissue research programs devoted to the study of the actinide elements in man. In addition to their own scientific research activities, the Registries have active collaborations with 13 other laboratories, including one in the United Kingdom. The Transuranium Registry has received a total of 258 postmortem donations, including seven whole bodies, and currently has 509 living registrants of whom 25 are whole body donors. The Uranium Registry has 31 living registrants, including two whole body donors, and has received eight postmortem donations, including one whole body.

The emphasis of the Transuranium Registry was directed towards evaluation of six whole body donations. In the five cases whose exposure was through inhalation, approximately half of the total body content of Pu-239+240 and a third of the Am-241 was found in the respiratory tract, suggesting that these nuclides are more avidly retained than predicted by the current model of the International Commission on Radiological Protection. A significant fraction of these nuc1ides is found in soft tissues other than 1iver, and an uptake fraction of 0.2 is proposed for muscle, with a residence half-time of 10 years. Studies of these and routine autopsy cases indicate that more than 90 per cent of the total respiratory tract plutonium or americium is in the lungs, with the remainder in the lymph nodes, and that a greater fraction is found in the lungs of smokers relative to the lymph nodes.

Primary activities of the Uranium Registry centered around the acquisition of a whole body donation from a woman who had received an injection of colloidal thorium dioxide some 38 years prior to death.