Case study: What the Fukushima water release reveals about risk perception and communication

When Japan began discharging treated water from the Fukushima Daiichi nuclear plant into the Pacific Ocean in August 2023, it sparked international controversy and ignited social media firestorms in neighbouring countries.

The Chinese government banned the import of seafood from Japan and labelled Japan as “selfish” and “irresponsible”. South Korean citizens and fishers expressed fear and anger, holding protests outside the Japanese embassy. Protests also took place in Japan itself, as citizens raised concerns over the potential environmental and health impacts of the release.

However, the International Atomic Energy Agency (IAEA) concluded that the release would have negligible impacts. The UN’s atomic watchdog said the tritium concentration was well below the “operational limit”. The water was treated to remove all radioactive elements and was diluted to reduce radioactivity to 1,500 becquerels per litre (the drinking water standard is 10,000 Bq/L).

Ahead of the release, Professor Paul Leonard, Fellow of the Society for Radiological Protection, said: “The proposed discharge of tritium from Fukushima is being undertaken under suitable conditions and in radiological terms, the environmental impact on the public and seafood is negligible.”

“We were 100% opposed to the water release, we still oppose it, and we will continue to oppose it.”

In March 2024, Rafael Mariano Grossi, director general of the IAEA, said that the ongoing discharge of treated radioactive wastewater “has met safety standards” and that “any restrictions on products from the region are ‘not scientific’.”

Yet protesters saw the situation differently. Haruo Ono, 71, who has fished off the Fukushima coast since he was 15, told the Guardian: “We were 100% opposed to the water release, we still oppose it, and we will continue to oppose it. The government hasn’t listened to fishing communities in deciding how to deal with the water. It has abandoned the people of Fukushima.”

This mismatch between the risk presented by science and that perceived by the public offers a view into how such cross-border events trigger local anxiety. Two recent studies demonstrate that managing the perception of risk is often as crucial as managing the hazard itself.

FEAR SUPERSEDES ANGER

A Chinese study published in May 2025 analysed 111,660 posts on the Weibo social media platform after the first discharge. Researchers tracked attention and emotion over time. They found that public attention peaked within the first two weeks and then waned. Fear was the dominant emotion, persisting long after anger faded.

Engagement was higher in coastal provinces where seafood plays a larger role in diets, yet risk perception itself showed no consistent geographic gradient. The study also examined what drove people to communicate about the event. Communication intensity dropped over time, while higher fear scores correlated with greater engagement.

Socio-economic factors mattered: provinces with higher education levels and per-capita seafood consumption showed more discussion. Economic indicators such as per-capita GDP did not predict communication, indicating that risk perception cuts across wealth.

The authors proposed a three-pronged governance framework for transnational risk communication: target messaging during critical time windows, tailor communications to coastal communities and address persistent fear.

A survey of 987 South Korean adults, published in August 2025, painted a similar picture of fear overriding fact. Respondents were questioned in November 2023, just months after the discharge. Risk perception was associated with subjective knowledge, perceived involuntary exposure and a feeling of low controllability over the situation.

Trust in both cases influenced risk perception: low trust amplified fear, but even high trust led to anxious individuals seeking more reassurance from authorities. The researchers concluded that anxiety about involuntary exposure can linger for years and must be addressed through two-way communication and collaboration between governments.

These findings align with psychological research showing that nuclear-related hazards are perceived as “high-dread and low-controllability” risks. Perceived involuntary exposure emerged as a powerful driver of anxiety. Fear thrives where people feel powerless, uncertain and distrustful of information.

The Chinese social media study adds a temporal dimension: anger is a transient emotion that subsides, while fear continues to drive communication. Given that fear, not anger, is the emotion that motivates people to speak up on social media, companies monitoring stakeholder sentiment should not assume that falling anger signals the end of reputational risk.

GETTING COMMUNICATION RIGHT

Health-risk communication studies provide a cautionary tale about what happens when messages are unclear or late. A review of public health actions after the Fukushima disaster noted that appropriate and targeted risk communication early in an emergency can reduce health impacts and promote food safety.

The same analysis argued that risk communication should be organised according to public health ethics and scientific evidence, as generic messages that fail to consider individuals’ situations can be misunderstood and deepen fear.

Long-term recovery efforts in Fukushima show that two-way, community-based communication is essential. A study documenting recovery programmes in evacuated Japanese towns emphasised the importance of universities and health experts setting up satellite offices in municipalities, providing face-to-face consultations and tailored guidance.

“Health-risk communication studies provide a cautionary tale about what happens when messages are unclear or late”

Trust only emerged when experts listened to residents’ specific concerns, rather than pushing generic reassurances, while small-scale consultations and open-door channels allowed evacuees to discuss both radiation fears and broader health or livelihood issues.

The same research stresses that mental health support is crucial, as psychological distress is often a greater public health issue than radiation itself.