Fallout plutonium concentration in Japanese tissues: A new look at the old samples

Since 1962, we have been investigating the levels of^239,240Pu in human tissues. In the 1960s, the quantities of^239,240Pu found in the gonad and spleen were higher than those in liver and lung, as reported in our previous papers. This work was done to provide a reassessment of^239,240Pu distribution among several tissue samples from the 1960s and early 1970s, using current analytical techniques for plutonium. The autopsy tissues were collected from the Hospital of Niigata Prefectural Institute for Cancer Research in Northern Japan from 1968 to 1975. The subjects were at least 50 years old at the time of death. The accuracy and precision of^239,240Pu determinations were examined using NBS-SRM 4352 human liver samples. Our results are consistent with certified values.