Kinetics of Inhaled Krypton in Man

Publisher Website
Google Scholar
Abstract
The total body retention of 79Kr and its clearance following a 10-min rebreathing period were measured in vivo in order to refine the dosimetry calculations. Radioactivity in the chest region and in the recirculating krypton-air mixture were measured continuously during rebreathing of the gas mixture and in the first 5 min of the gas washout period using a gamma camera and shielded NaI detector, respectively. Subjects were then counted in the Brookhaven whole-body counter at varying time intervals for up to 55 hr. The retention data of krypton for 16 subjects (12 males, 4 females) were resolved into a five-component exponential curve. The average half-times were 21.5 ± 5.7 sec, 4.74 ± 2.0 min, 0.33 ± 0.11 hr, 2.41 ± 0.95 hr, and 7.0 ± 1.7 hr. The half-time of the long-term component correlated highly with the percentage of total body fat. Internal dose calculations were performed using the MIRD techniques and were compared with previous estimations.