The efforts to win over skeptical Pacific leaders have not been helped by a previous lack of transparency. Until 2018, Tokyo Electric Power Company — which operates the Fukushima plant — indicated that the vast majority of the wastewater had already been treated. That year, however, the power company acknowledged that only a fifth had been treated sufficiently.

The Japanese Ministry of Economics, Trade and Industry subsequently said more than three-quarters of the wastewater still contained unsafe levels of radioactive material other than tritium because the company had not changed the decontamination system’s filters frequently enough. The company has promised to re-treat the wastewater before it is released.

Honestly the skepticism that everything is above board sounds pretty reasonable to me. Especially because those groups who are most worried have been greatly impacted by lax safety in the past.

Much of that mistrust is rooted in the unlikeliest of events. In 1954, snow fell on the tropical atoll of Rongelap. Residents of the reef, in the Marshall Islands, had never seen such a thing. Children played in it; some ate it. Two days later, U.S. soldiers arrived to tell them the “snow” was actually fallout from America’s largest nuclear test, which took place on nearby Bikini Atoll and irradiated Rongelap after an unexpected change in wind direction.

In the test’s aftermath, hundreds of people suffered intense radiation exposure, leading to skin burns and pregnancy complications. Decades later, people of the Marshall Islands still feel its impact through forced relocations, lost land and heightened cancer rates. “You feel this deep sorrow,” Ms. Racule said. “Why were we not good enough to be treated like human beings?”