Will the planned water releases from the Fukushima Dai’ichi nuclear plant be harmful to people?

This blog was written by Leslie Mabon, a Senior Lecturer in Social Science at the Scottish Association for Marine Science-University of the Highlands and Islands and a Future Earth Coasts Fellow.

In October 2020, it was reported in The Guardian, Japan Times, New Scientist and elsewhere that the government of Japan intends to approve plans to release treated water stored at the site of the Fukushima Dai’ichi nuclear plant into the north-west Pacific Ocean. The Great East Japan Earthquake and Tsunami of 11 March 2011 disabled cooling systems at the power station, triggering hydrogen explosions and causing three of the plant’s reactors to suffer meltdowns. Since then, water used to keep the damaged reactors cool, plus recovered groundwater, has been treated to remove the most harmful radioactive substances and then retained on-site in storage tanks. However, plant operator Tokyo Electric Power Company claims they will run out of space by 2022. An expert panel has concluded that releasing the treated water into the sea is the most effective response. Yet a breadth of news sources report that local fishers and environmental NGOs object to the releases on the grounds of potential health effects and/or stigmatization of Fukushima seafood. In one Guardian article, Greenpeace even claimed that the water could damage human DNA if released.

What does the underpinning science say?

One of the most up-to-date overviews of the situation at the Fukushima Dai’ichi plant was published by Ken Buesseler of Woods Hole Oceanographic Institution in Sciencein summer 2020. Buesseler explains that tritium – the radioactive substance most commonly cited as a cause for concern when the releases are discussed – is relatively harmless and does not exist at the Fukushima Dai’ichi site at a volume higher than what would normally be released by a nuclear power station. However, Buesseler also points out that the storage tanks may also contain other radioactive substances such as ruthenium-106, cobalt-60, and strontium-90. These materials may behave differently to tritium in the ocean, and may be more readily incorporated into marine species or the seabed. Buesseler concludes that to fully understand the consequences of releasing treated water into the sea, a full assessment of what is contained in the tanks needs to be undertaken.

Although the science addressing the material contained in the tanks at Fukushima Dai’ichi is still emerging, there is a wider body of research addressing the effects of radioactivity on the marine environment since the 2011 accident. For example, in a 2016 commentary, Jordi Vives i Batlle summarises that whilst the risks to humans and marine species are low, the contamination of the marine environment in Fukushima is significant. A team of researchers led by Fukushima University and Fukushima Prefecture’s fisheries experimental station similarly concluded in 2016 that with the procedures and regulations that are in place for monitoring and screening of Fukushima produce, the risk of consumption of Fukushima seafood is low or negligible, with no additional radiological effects for consumers.

In sum, whilst it is true that radioactivity from the plant exists in the Fukushima environment and that uncertainties over the treated water remain, the peer-reviewed science suggests it is very unlikely that humans will be exposed to harmful radiation. Nonetheless, a team led by the Scottish Association for Marine Science and Tokyo University of Marine Science and Technology interviewed local fishers in Fukushima to understand their views towards the releases, publishing their results in autumn 2020 in the International Journal of Disaster Risk Reduction. They found that fishers in Fukushima were worried about the future of the plant, and about the effects of treated water releases on public perceptions of Fukushima seafood given their pride in the fish they caught. Crucially, this paper found that more than concerns over the safety of treated water or of marine produce, fishers very much valued the opportunities that trial-scale fishing had given them to rebuild their livelihoods post-disaster. Accordingly, anything that jeopardised this fragile recovery was viewed as having the potential to undo the gains made since 2011 in helping Fukushima fishers to rebuild their lives.

How well does the media describe the science?

New Scientist carries the views of a breadth of marine scientists on the releases. It reports a general consensus that the releases are unlikely to pose risks to humans or marine species, but also acknowledges Buesseler’s concern over remaining uncertainties around what is contained in the tanks and also the need for close monitoring once treated water is released. The Guardian’s reporting around the subject touches on the views of fisheries officials from Fukushima Prefecture, but otherwise engages to only a limited extent with the peer-reviewed literature whilst reporting the assessments of a Greenpeace investigation. Deutsche Welle similarly reports the scientific assessment of Greenpeace and also a study carried out by a local newspaper, but does not carry the views of scientists working at academic research organisations or refer to peer-reviewed studies.

Other points to bear in mind

The concerns expressed by fishers and citizens of Fukushima Prefecture are not only about the safety of treated water or of local seafood. Fisheries are a significant component of local identity on the Fukushima coast. Efforts to rehabilitate local fisheries following the 2011 nuclear accident have gone a long way to re-establish a sense of pride and purpose among fishers and coastal communities. Catching and selling high-quality seafood is not only an economic activity, but rather a whole way of life for those involved, and an important part of a sense of belonging for those that live on the Fukushima coast. Consequently, anything such as a release of treated water that may jeopardise this recovery or lead to Fukushima fish being viewed as ‘tainted’ is likely to be met with concern.

Similarly, there is a strong body of social science research which tells us that people’s perceptions of radioactivity are complex, and thus that it is a mistake to dismiss concerns as ‘irrational’ or ‘wrong’. Different groups of people may interpret uncertainties and unknowns differently, depending on what they consider an acceptable level of risk. Our interpretation of risks can be informed by a breadth of factors, including whether we trust the individual or organisation taking the risk on our behalf, what our political views are, and whether we consider the distribution of risks and benefits (or the decision-making process) to be fair. Providing ‘more’ or ‘better’ science alone is unlikely to be effective when it is issues of value that are at stake.

Useful links

An explainer about the Fukushima Dai’ichi treated water situation on Leslie Mabon’s research blog

A virtual tour of the Fukushima coast on Leslie Mabon’s research blog

Fukushima InFORM – monitoring the effects of the Fukushima nuclear accident on Canada’s oceans

Woods Hole Oceanographic Institution – Center for Marine and Environmental Radioactivity

‘The Sea of Fukushima Will Not Give In’ – short film about Fukushima fisheries produced by Fukushima Prefecture

Leslie Mabon’s current work on the coasts and seas of Fukushima Prefecture is supported by Economic and Social Research Council-Arts and Humanities Research Council UK-Japan Social Sciences and Humanities Connections Grant ES/S013296/1, ‘Building social resilience to environmental change in marginalised coastal communities.‘