Combating ‘fake news’ and social stigma after the Fukushima Daiichi Nuclear Power Plant incident—the importance of accurate longitudinal clinical data

The health effects of radiation-release incidents are diverse and long-term. Many victims of previous radiation-release incidents faced long-term impacts.1 Although managing direct and indirect radiation effects is crucial after radiation-release incidents at an individual level,1 it is also important to appropriately cope with social impacts on the local community and the public. While social impacts are represented by stigma toward radiation such as avoidance of consuming tap water and local products, avoiding affected areas, and misconception regarding radiation exposure including bullying among evacuated victims after nuclear disaster,2–5 little information is available on possible contributors and necessary countermeasures to reduce such public stigma after radiation-release incidents. Here, we would like to introduce our experience eight years after the Fukushima Daiichi Nuclear Power Plant (FDNPP) incident and lessons to be learned from it. In October 2018, a printed leaflet regarding an increase of malignancy after the FDNPP incident was distributed to citizens in Minamisoma city, which is located near the FDNPP and is one of the areas most affected by the FDNPP incident (Fig. 1). Incidence of thyroid cancer and leukemia was reported to have increased 29 and 11 times, respectively, after the FDNPP incident. It later turned out that these data were created using biased interpretation of health insurance claims data in the Minamisoma Municipal General Hospital, a core medical institution in the city. Such data are often inaccurate and should not be used to calculate cancer incidence, because the database shows only the roughly cumulative numbers of diseases in a hospital.6 In this case, there was only one incidence of thyroid cancer in 2010 before the FDNPP incident, and this number progressed to 29 in 2017 even though there were only four newly diagnosed thyroid cancer cases in the hospital in 2017. Therefore, the ‘29 times higher incidence of thyroid cancer’ indicated by these data is a biased interpretation. Surprisingly, a city council member started distributing this information. In addition to distribution to citizens, this information drew national attention via social networking services (SNSs) and the Internet. To make matters worse, the local government did little to stop the council member from spreading such misleading information since they did not have accurate information about the disease incidence. Minamisoma city is located 13–38 km north of the Fukushima Daiichi Nuclear Power Plant (FDNPP). Immediately after the FDNPP incident on 12 March 2011, the Japanese government declared the area within a 20- and 20–30-km radius of the FDNPP a mandatory evacuation zone and an evacuation-prepared area, respectively. This regulation greatly impacted the residents in the city. Although negligible health effects of direct radiation exposure were reported after the incident by the Japanese government and the international authorities such as the International Atomic Energy Agency and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), the local residents remained concerned about whether they would develop radiation-related health disorders—namely, cancer—in the future in the context of strong remaining stigma toward radiation. Minamisoma city is located 13–38 km north of the Fukushima Daiichi Nuclear Power Plant (FDNPP). Immediately after the FDNPP incident on 12 March 2011, the Japanese government declared the area within a 20- and 20–30-km radius of the FDNPP a mandatory evacuation zone and an evacuation-prepared area, respectively. This regulation greatly impacted the residents in the city. Although negligible health effects of direct radiation exposure were reported after the incident by the Japanese government and the international authorities such as the International Atomic Energy Agency and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), the local residents remained concerned about whether they would develop radiation-related health disorders—namely, cancer—in the future in the context of strong remaining stigma toward radiation. This case highlights that negative information can easily spread among local residents and the broader public, and stigma regarding radiation exposure remains even eight years after the FDNPP incident in 2011. The biggest reason for the spread of such misleading information was insufficient accumulation of fundamental disease databases after the FDNPP incident. To date, there are no cohort data regarding incidence and prevalence of cancer and non-communicable diseases (NCDs) among those affected by the FDNPP incident. Without such data, stigma may become serious each time such incorrect information spreads. After previous radiation-release incidents, it was reported that the increased incidence of various types of cancer, such as thyroid cancer and leukemia, as well as other NCDs among those affected are associated with ionizing radiation exposure.7,8 However, no cohort data are available on the incidence of such diseases as the previously accumulated databases had technical flaws and were not linked with other national databases after the FDNPP incident. Thus, discussions about cancer incidence, which could be critical after radiation-release incidents, have not yet deepened after the FDNPP incident. Despite no discernible health effects of direct radiation exposure being reported,9 it is necessary to build valid disease databases and verify the incidence of diseases that may be affected by radiation-release incidents. However, there are some barriers to building out the fundamental disease databases. For example, it is hard to simply compare cancer incidence in Japan before and after the FDNPP incident, because the accuracy of the hospital-based cancer database in Japan was questioned before the regulation of the Japanese national cancer database was renewed in 2013. Accordingly, its expansion of covered hospitals in the reestablished database led to an increase in the apparent incidence in all types of cancers. Insufficient accumulation of disease databases inhibits calculation of accurate incidence of the diseases associated with the incident at the time of disaster. Tendency for misleading and attracting information (e.g. ‘fake news’) to spread easily may also be associated with spreading misleading information. In SNSs, irrational information often spread despite no reference after the Fukushima nuclear disaster. Particularly on Twitter, a major SNS, roughly half of radiation-related information was spread by accounts defined as ‘influencers’, whose tweets were frequently dispersed regardless of accuracy.10 If influencers continue to transmit only biased information, the general public may be exposed only to such information. As biased information is often shocking, people may be likely to believe it despite a lack of a proven scientific source. Transmission of accurate information via various methods from mass media, stakeholders and the government would be helpful to mitigate a spread of such biased information. Another reason for spreading incorrect information may be that knowledge regarding radiation still has not reached the general public. In 2017, bullying toward evacuated children associated with stigma around radiation after the FDNPP incident became a social problem in Japan. This affair also highlighted the insufficient knowledge regarding radiation and the need for continuous education on radiation in Japan.5 In the above case, if people had sufficient knowledge of radiation exposure, they might have found it unreasonable that the incidence of thyroid cancer increased 29 times after the FDNPP incident. It is essential to enhance the general knowledge level regarding radiation to help the general public determine whether information is scientifically reasonable. One provision to mitigate social impacts on the local community and public is to show accurate epidemiological data. This can also deny biased information; however, it could not be applied in the FDNPP incident. Collecting fundamental disease databases after the FDNPP incident will link the accurate incidences of diseases that could be affected by radiation-release incidents and would be an important reference for future nuclear disasters, although it might simultaneously be harmful for local residents. For example, despite minimal internal thyroid radiation exposure among local children, local professionals are facing a dilemma that implementation of thyroid cancer screening for children itself makes local people nervous. It is not easy for stakeholders to determine how to gather such complicated data. Lessons from this experience are that accumulation of fundamental disease databases, including cancer; several methods of sharing accurate information; and enhancing the knowledge level regarding radiation may be helpful to alleviate spreading incorrect information after radiation-release incidents. Minamisoma city is located 13–38 km north of the Fukushima Daiichi Nuclear Power Plant (FDNPP). Immediately after the FDNPP incident on 12 March 2011, the Japanese government declared the area within a 20- and 20–30-km radius of the FDNPP a mandatory evacuation zone and an evacuation-prepared area, respectively. This regulation greatly impacted the residents in the city. Although negligible health effects of direct radiation exposure were reported after the incident by the Japanese government and the international authorities such as the International Atomic Energy Agency and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), the local residents remained concerned about whether they would develop radiation-related health disorders—namely, cancer—in the future in the context of strong remaining stigma toward radiation. None. We would like to thank Mr Masatsugu Tanaki for his constructive opinions on this study and Editage (www.editage.jp) for English language editing. Conflict of interest: None declared.