system that can remove radionuclides, except tritium, to a level that Japanese regulations allow to be discharged to the sea. As of December 2019, 28% of the water had been purified to the required level, while the remaining 72% needed additional purification. However, tritium cannot be separated from the water. As of October 2019, the total amount of tritium in the water was about 856 terabecquerels, and the average tritium concentration was about 0.73 megabecquerels per liter. A committee set up by the Japanese Government concluded that the purified water should be released to the sea or evaporated to the atmosphere. The committee calculated that discharging all the water to the sea in one year would cause a radiation dose of 0.81 microsieverts to the local people, whereas evaporation would cause 1.2 microsieverts. For comparison, Japanese people get 2100 microsieverts per year from natural radiation. IAEA considers that the dose calculation method is appropriate. Further, IAEA recommends that a decision on the water disposal must be made urgently. Despite the negligible doses, the Japanese committee is concerned that the water disposal may cause reputational damage to the prefecture, especially to the fishing industry and tourism. On 9 February 2021, the Catholic bishops of Japan and Korea voiced their opposition to the plan to release the water into the ocean, citing further opposition by fisheries, local prefecture councils, and the governor of Jeju Province. Tanks used to store the water are expected to be filled in 2023. In July 2022, Japan's Nuclear Regulation Authority approved discharging the treated water into the sea. Other radioactive substances created as a byproduct of the contaminated water purification process, as well as contaminated metal from the damaged plant, have drawn recent attention as the 3,373 waste storage containers for the radioactive slurry were found to be degrading faster than expected. Risks from ionizing radiation Although people in the incident's worst affected areas have a slightly higher risk of developing certain cancers such as leukemia, solid cancers, thyroid cancer, and breast cancer, very few cancers would be expected as a result of accumulated radiation exposures. Estimated effective doses outside Japan are considered to be below (or far below) the levels regarded as very small by the international radiological protection community. In 2013, the World Health Organization reported that area residents who were evacuated were exposed to so little radiation that radiation-induced health effects were likely to