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  The names of those killed when the atomic bomb was dropped on Hiroshima, Japan, in 1945 are held in the Memorial Cenotaph at Hiroshima Peace Memorial Park.

By LAUREN N. MAYNARD

Published: August 5, 2009

Within three kilometers from ground zero of one of history’s most devastating wartime events, scientists at the Radiation Effects Research Foundation (RERF), collaborating with UB faculty member Randy Carter, are busy working the numbers on population-based studies of survivors of the Hiroshima and Nagasaki atomic bomb detonations.

The RERF conducts a variety of statistical, epidemiological, clinical and basic science research through its Adult Health Study (AHS) and Life Span Study (LSS) cohorts. The AHS involves a cohort of more than 20,000 living survivors of the Hiroshima and Nagasaki bomb blasts; there are approximately 77,000 survivors still alive in the LSS cohort. RERF also monitors mortality causes and cancer incidence of children (born between 1946 and 1984) of those survivors.

Established as a nonprofit foundation in 1975, the RERF was primarily a U.S. research entity in Japan immediately following World War II. Today, it is the pre-eminent, multidisciplinary radiation exposure research facility in the world and is funded by the Japanese Ministry of Health, Labor and Welfare and the U.S. National Academy of Sciences, under contract with the Department of Energy.

Carter, professor and associate chair of biostatistics in the School of Public Health and Health Professions, is a veteran consultant at the RERF. The current system at RERF for estimating radiation doses is the dosimetry system, which uses physical measures like distance and shielding only to calculate doses. Carter travels to Japan several times a year to work with RERF statisticians on methods to incorporate biological effects into the calculations and thus improve the dosimetry system.

Carter and the RERF’s statistics department work on methods, models and software that analyze the survival data—such as cancer death rates—of the bomb survivors. Their goal is to develop more accurate summaries of the subtle and complex radiation effects seen in the survivors; these reports would try to answer many important and challenging statistical problems that remain after more than 50 years of analyzing atomic bomb survivor data.

“RERF estimates of the effects of radiation are used around the world to set limits on radiation exposure, but there have been long-held concerns about overestimating safe limits because of error in survivors’ recall of their location and shielding at the time of the bomb,” Carter says.

Carter also directs the Population Health Observatory (PHO), a relatively new center at SPHHP dedicated to conducting population-based research. Faculty and student researchers at the PHO conduct statistical investigations with several local organizations, and the RERF represents a major international collaboration.

Since 2006, the PHO has collaborated with the RERF to develop statistical methods to adjust for measurement error in estimates of radiation doses suffered by atomic survivors in Japan. The PHO also works with RERF scientists on other studies involving health data from cohorts in Japan and Western New York.

Former Ph.D. students Austin Miller, ’09, and Carmen Tekwe, ’09, have made large contributions to the UB-RERF collaboration; they visited the RERF twice overseas, and RERF researchers served as members of their dissertation committees.

Last year, Tekwe spent three months in Hiroshima working with Carter and RERF researchers on the dosimetry database as part of her dissertation project. Her work involves extending a class of causal models, called MIMIC models (Multiple Indicators, Multiple Causes models), to adjust for the error in dose estimates that results from survivor recall error. Miller’s work focused on using biological effects of exposure to better estimate individual doses. He presented his final results in Japan in January; Tekwe’s talk was a year earlier.

“All the feedback I’ve gotten suggests that their work is highly valued by RERF statisticians,” Carter says.