Review of radiation doses suffered by A-bomb survivors to begin

by Hiromi Morita, Staff Writer

The Scientific Council of the Radiation Effects Research Foundation (RERF), which met on March 2, announced that RERF will launch a project team in fiscal 2009. The team will review basic data on individual radiation doses suffered by atomic bomb survivors and enhance the accuracy of the research.

The team will work with about 100,000 survivors, on whom follow-up surveys have been conducted since 1958. They will calculate the individual radiation doses with a method called dosimetry system 2002 (DS02), designed to estimate levels of radiation exposure, taking into account the total amount of radiation emitted by the atomic bomb and the distance between the hypocenter and where the survivors were at the time of the bombing.

The work poses several problems, though: 1) A consistent approach to interpreting data that was collected through interviews at the time of the atomic bombing is still lacking; 2) The map made by U.S. forces, to pinpoint the locations of survivors, suffers from distortion; and 3) There are some survivors whose estimated radiation dose is “unclear” because details involving objects that helped shield them from the blast are unknown.

The team will therefore review the existing data over the next few years, focusing on the original interview sheets. They will also develop a consistent approach to interpreting this data that faithfully reflects the conditions experienced by the survivors at the time of the bombing. And they will strive to accurately gauge the estimated doses of radiation. The chairman of RERF, Toshiteru Okubo, commented, “Now that internal exposure due to residual radiation is drawing public attention, more accurate estimates of individual radiation doses would bolster the credibility of various research data.”

About 30 people, including scientific advisors from Japan and the U.S.--officials from both the Ministry of Health, Labor and Welfare, and the U.S. Department of Energy--participated in the closed-door talks in the Scientific Council. The Council reported on a continuing research project concerning second-generation survivors on March 2, and will conclude the talks with recommendations on March 4.

(Originally published on March 3, 2009)

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