2015 Volume 66 Issue 3 Pages 412-428
This study, which focuses on the health effects of radiation exposure following the Fukushima Daiichi nuclear accident, examines how we should discuss uncertainty in the context of environmental risks. In the debate on radiation exposure, scientists who support the government's policy have admitted that the scientific knowledge that underpins the policy is questionable. However, they seem to discuss uncertainty in generalized and superficial terms, hesitating to discuss “specific uncertainties” with reference to particular academic papers or research. This can obstruct constructive discussions between different parties. I examine the minutes of two government-established working groups' discussions on radiation exposure.
I found that these groups were strikingly different, both quantitatively and qualitatively, in how they discussed uncertainty. The Working Group on Risk Management of Low-Dose Radiation Exposure, exclusively comprising experts on radiation and nuclear engineering, did not frequently mention uncertainty. It repeatedly referred to the reports of international organizations such as the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and the International Commission on Radiological Protection (ICRP). It did not consider critically the basis of an “international consensus.” In contrast, the Working Group of the Food Safety Commission included scientists specializing in chemical risks, who instead of relying on “international consensus,” discussed particular academic papers, paying attention to uncertainty in relevant scientific knowledge. They showed “negative self-reference,” that is, systematic consideration of specific uncertainties, particularly in the scientific knowledge that facilitated the group's arriving at conclusions. The discussion based on negative self-reference revealed each member's attitude toward the risk of radiation exposure and demonstrated how the group reached its conclusion from an external perspective. This study also suggests that the participation of non-expert members in the groups obstructed negative self-reference in some cases.
