210 DASA 2019-2 reduced practically to zero. You see on their return to Rongelap, the increase in cesium and zinc. Strontium-90 also began to appear, and this had to be detected not by whole-body counting but by radio- chemical analyses of the urine. The levels reached a peak about 1961 or so and during the past year a drop in urinary excretion has occurred, indicating lowering of body burdens. Cesium peaked ata little less than 1 microcurie of body burden, which is not high, but it represents about 300 times the level in those of us in the medical team that were counted. In regard to zinc, it reached a peak at about the same time that the cesium did but suddenly within one y ~'s time it dropped to about 1/10 of the previous year's value. I we , Lauren, do you have any comment on that, aa to why we had «ita sudden drop in zinc-65 in the people? Was something happening to the fish then that caused ct Nees this sudden change? DONALDSON: CONARD: They had been eating rice pretty much all along. DONALDSON: DUNHAM: When did they get rice? Their food habits can change radically. There wasn't a difference in your counter at that point? FREMONT-SMITH: Don't suggest that! EISENBUD: Whatis the half-life of zinc-65? I don't rernember, DONALDSON: believe, CONARD: Less thana year. I should know, but Two hundred and fifty days, I But that wouldn't account for a sudden change? DONALDSON: to look them up. [If I remember the data correctly~and | would have Ihave them here. Essentially there his been no drastic change in the usually expected declines. If they have changed their habits not only in eating fish but aiso in eating birds, and if they've had expeditions to the north island and come oac’. with lots of birds, that would increase it.