Asahi Shimbun GLOBE: The Japanese Government Demanded Revisions of the 2012 WHO Report on Fukushima Radiation Exposure / 修正を迫られた福島被曝報告書

The December 7, 2014 issue of the Asahi Shimbun GLOBE, a for-fee division of the Asahi Shimbun website, featured a series of articles on World Health Organization (WHO). It included an article whose title translates into Revision Demanded of the Fukushima Radiation Exposure Report.”

The Japanese Government Demanded Revisions of the 2012 WHO Report on Fukushima Radiation Exposure

Written by Yuri Oiwa

A high level Ministry of Health, Welfare and Labour (MHWL) official heard the cell phone ring. It was a Saturday morning in November 2011. “We have a problem.” It was from a younger colleague who was looking right at a draft copy of the dose estimation report due to the nuclear accident that WHO had been working on.

It showed thyroid exposure doses of 300 to 1000 mSv for infants from Namie Town, Fukushima Prefecture, and 10 to 100 mSv for infants even in Tokyo and Osaka. According to UNSCEAR’s report on Chernobyl, thyroid cancer was found in approximately 6,000 people, and thyroid exposure dose for evacuees was several hundred mSv. Some studies report thyroid cancer increased with exposure dose above 50 mSv.

“WHO’s estimate is substantially higher than the reality.” The Japanese government worked at having WHO revise the estimates by offering new data such as the food monitoring results.

In the WHO dose estimation report released in May 2012, thyroid exposure doses for infants was lowered to 100 to 200 mSv for Namie Town and 1 to 10 mSv for Tokyo and Osaka. As it was felt that this was still dissociated from the reality, the Japanese government requested revisions until moments before the release of the report, with then MHLW Vice Minister Shinji Asonuma conveying disappointment to Margaret Chan.

In February 2013, WHO released a health risk prediction based on these estimates, “In majority of Fukushima residents, a possibility for an obvious increase in cancer is low. Thyroid cancer risk might be increased in some infants.” Lifetime risk for thyroid cancer would be about 1.7 times higher at maximum.

There are 3 full-time employees at WHO in charge of radiation exposure issues. The WHO Fukushima reports were essentially written by an international group of radiation specialists at the request of WHO.

The UNSCEAR report released in April 2014 estimated thyroid exposure dose of 47 to 83 mSv, about half of the WHO estimates, for infants who were in the 20-30 km zone from Fukushima Daiichi NPP. Mikhail Balonov, a professor at the Institute of Radiation Hygiene in Russia and involved with both reports, explained, “UNSCEAR report created after the WHO reports is more realistic, as it reflects evacuation movements of the residents.” As for the criticism that the WHO reports are overestimation, the WHO manager in charge of the reports, Emilie van Deventer, said, “Considering uncertainties of estimation, it is not much different from the UNSCEAR report. The mission of WHO is to protect people’s health. Underestimation of risks must be avoided at any cost.”