After two turbulent years on the job, the head of Fukushima prefecture's massive survey to understand the health effects of the 2011 Japanese nuclear accident is stepping down. Shunichi Yamashita, a radiation health expert from Nagasaki University, told Nature by e-mail that he will leave his post at the end of March.
The Fukushima Health Management Survey is an ambitious project to chronicle any adverse health effects arising from the three meltdowns at the Fukushima Daiichi nuclear plant, caused by the tsunami and magnitude-9 earthquake off the coast of Japan on 11 March 2011.
The survey's goals include estimating the dose received by the prefecture's 2.05 million residents, thyroid screening of tens of thousands of children who may have been exposed to radioactive iodine-131, and understanding the mental-health consequences of the accident.
Yamashita, whose mother is a survivor of the atomic bomb at Nagasaki, is considered to be one of Japan's leading authorities on radiation health. Before coming to Fukushima, he was involved in studies of both the Japanese atomic bomb survivors and victims of the 1986 nuclear accident at Chernobyl in the Ukraine.
But Yamashita's tenure as head of the health survey has been marked by controversy. "He had a difficult start in Fukushima from the very first days," says Wolfgang Weiss, a German physicist and member of the United Nations Scientific Committee on the Effects of Atomic Radiation. Even as the Japanese government evacuated many areas in Fukushima, Yamashita insisted that radiation levels presented little risk, creating confusion.
He also made public gaffes, including telling Fukushima residents to smile and be happy, says Azby Brown, a member of Safecast, a Tokyo-based non-profit organization that monitors radiation in Fukushima prefecture.
"He was seen as being flippant and dismissive," Brown says. "He did a great job of running the actual study and a bad job of managing expectations and communicating to the public."