4 years have passed since the nuclear power plant accident at Fukushima, Japan, moving the problems there from an acute nuclear disaster to a chronic environmental disaster, with multiple social, psychological, economic, and political consequences. As described by Ohtsuru and colleagues, many people continue to experience multiple losses, both tangible and intangible, at the individual, family, and community levels. Putting Hiroshima and Nagasaki side by side with Fukushima, as done in this issue of The Lancet, seems inappropriate in major respects. Hiroshima and Nagasaki were intentional governmental acts of war, whereas Fukushima was accidental and negligent industrial behaviour in time of peace. They share exposure to radiation—but at vastly diff erent levels and in diff erent forms. In Fukushima, no one has died from radiation exposure, and the UN Scientifi c Committee on the Eff ects of Atomic Radiation report in 2013 stated that substantial changes in future cancer statistics attributed to radiation exposure are not expected to be observed, although the committee also noted “a theoretical increased risk of thyroid cancer among most exposed children” and recommended they be “closely followed”. However, putting these disasters together does reveal some shared characteristics. In Hiroshima and Nagasaki, people were “exposed to explosion” (hibaku in Japanese); while those in Fukushima are “exposed to radiation” (also hibaku in Japanese). These words share the same pronunciation, but use diff erent Japanese characters. Both groups are living with the social and psychological uncertainties and implications of possible radiation exposure. Both groups also became higaisha or victims. The apocalyptic disruptions of their lives did not arise from their own choices, but from social and political decisions taken by others. This reaction is common in radiation disasters worldwide. The survivors of a chronic environmental disaster typically seek redress around questions of care, compensation, and clean-up. Although chronic environmental disasters have important medical dimensions, the human losses go far beyond the medical sphere. Below we briefl y explore these three questions for Fukushima, examine the role of community engagement, and highlight changes needed to prevent another nuclear power plant disaster. Long-term responses in Fukushima need to provide eff ective care for the complex problems that people confront, including physical and mental health risks as well as community health, as noted by Hasegawa and colleagues and Ohtsuru and colleagues. Diff erent populations in Fukushima need diff erent kinds of care— for example, to address parental concerns about cancer risks for children, young women’s concerns about their marriage prospects, and evacuees’ profound challenges of social adjustment in relocated places. Many of these problems are multidimensional (involving radiation risks, social stigma, family confl icts), in ways that physicians are not trained to address. Questions of compensation frequently become sources of confl ict in cases of environmental contamination, as aff ected people seek monetary redress for their economic, health (both physical and mental), material, and social losses. Confl icts often arise around who should be compensated, what should be compensated, how values should be determined, and how long compensation should continue. These issues have led to a fl ood of lawsuits in Fukushima, against both the Tokyo Electric Power Company and Japan’s central Government. According to one review of the litigation for nuclear damages related to Fukushima, the fi nancial magnitude was calculated at approximately ¥10 trillion (US$110 billion) and involving more than 1·5 million claimants. This makes it “the largest civil liability case in the legal history of not only Japan, but probably the world”. The lawsuits raise major legal, fi nancial, and political implications. The scale of clean-up needed in Fukushima Prefecture is enormous within the grounds of the destroyed Fukushima power plant and in the surrounding areas. The total amount of contaminated soil and materials from Fukushima Prefecture alone is estimated to reach 22 million cubic metres, “equal to fi lling the Tokyo Dome [a baseball stadium] 18 times”. The shortage of adequate storage sites contributes to delays in decontamination work and to indecision by some former residents who wonder whether to return home or relocate elsewhere permanently. The decontamination eff ort is expected to last until at least 2017 and cost an estimated ¥1300 billion. These ongoing clean-up activities, near areas where people are living, create profound social unease, in part because of the invisible nature of radiation. A coalition of technical experts in Japan and other countries examined the decontamination activities and raised crucial questions about whether the clean-up will “contribute to the restoration and rebuilding of the lives of those aff ected”. The International Commission on Radiological Protection (ICRP), in its report on people “living in long-term contaminated areas”, concluded that those people need to be involved in the management of the “existing exposure situation”. Additionally, the ICRP stated, “[T]he responsibility of authorities at both national and local levels [is] to create the conditions and provide the means favouring the involvement and empowerment of the population.” In short, living with long-term contamination needs community engagement—especially to address the related problems of care, compensation, and clean-up. Lancet 2015; 386: 498–500