ASSIMILATION AND BIOLOGICAL TURNOVER OF CESIUM-134 IODINE-131 AND CHROMIUM-51 IN BROWN CRICKETS ACHETA DOMESTICUS (L)

Understanding of radionuclide accumulation by insects requires careful assessment of assimilation and turnover rates. In separate experiments, three radionuclides (134Cs, 131I or 51Cr) were fed to adult brown crickets for a 24-hr period. The insects were then transferred to nonradioactive food and their whole-body retention measured at 1-hr intervals. The retention of each radionuclide can be described by a sum of two exponential functions, a shorter one related to loss of unassimilated radionuclide from the gut and a longer one describing excretion of assimilated radionuclide from tissues. The shorter components had similar rates (half time = about 4 hr) for all three radionuclides, indicating that they were a measure of gut clearance time. Chromium had the lowest assimilation (6%) and cesium the highest (65%). Assimilated 134Cs and 51Cr were eliminated at moderate rates (biological half lives of 62 and 83 hr, respectively) but assimilated 131I was stored rather than excreted. © 1969 Health Physics Society.