Effects of duration of fast and animal age on the gastrointestinal absorption of plutonium.

The fraction of plutonium absorbed after oral administration of Pu(VI) to 24-h-fasted mice was 19 X 10(-4), 13-fold higher than in fed mice, 1.4 X 10(-4). We have investigated the relevance of the high gastrointestinal (GI) absorption value for the 24-h-fasted animals in setting drinking water standards for humans.

Adsorption of Pu, Pb and Cd to mouth surfaces during oral administration to mice.

Substantial adsorption of Pu, Cd and Pb onto mouth surfaces of mice occurs during consumption of drinking water that contains these elements. If this adsorption is not taken into account, the amounts deposited in the eviscerated carcass (muscle plus skeleton) after gastrointestinal absorption are overestimated by 2-9 times for the experiments described. An evaluation of data indicate that significant adsorption can also occur during gavage administration.

Distribution and retention in bone of 226Ra and comparison with the ICRP 20 model.

Analyses are presented of the ratios of 226Ra to calcium in over 650 samples of compact and cancellous bone from 66 female and 26 male subjects who had died from less than 1 to 60 yr after first exposure to radium. The 226Ra/Ca ratios were normalized to the terminal 226Ra skeletal content. The 226Ra/Ca ratios for vertebrae were essentially identical to those for other cancellous bone for a given subject.