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Diary of a Japanese nephrologist during the present disaster: part II

2011; Elsevier BV; Volume: 80; Issue: 1 Linguagem: Inglês

10.1038/ki.2011.130

1523-1755

Masaomi Nangaku, Tadao Akizawa,

Nuclear and radioactivity studies

Radioactive material was released from the Fukushima nuclear power plant as a result of deliberate venting to reduce gaseous pressure, deliberate discharge of coolant water into the sea, and accidental events. At first, our main concern was tiny radioactive substances that are carried along on the breeze, landing on our clothes and skin. We wore glasses and masks. My wife put a big cardboard box outside our house and told us to put on overcoats outside and keep them outdoors when we came home. Based on the data of Tokyo Metropolitan Institute of Public Health, the average aerial environmental radiation levels in Tokyo had been about 0.8 μSv per day before the crisis. On 14 March, the value suddenly went up to 2.6 μSv per day. On 16 March, the embassy of France, which is very developed in terms of nuclear power utilization, advised French people to go back to France or move to the western part of Japan immediately. The aerial environmental radiation level peaked at 3.5 μSv per day on 23 March and then declined and persisted around 1.8 μSv per day. As a matter of fact, this value, which corresponds to 0.7 mSv per year, is not very high. However, many people still kept windows shut and did not use air fans in order to avoid influx of radioactive substances in the air. A colleague sent his kids to stay in the western part of Japan during spring school vacation and said to me, “Why should our kids have to stay in Tokyo under a radioactive atmosphere and just waste electricity while power is short?” A bigger concern was contamination of the food chain by radioactive substances. On 19 March, this concern became a reality. The government announced the detection of the radioactive form of iodine, iodine-131, in milk, spinach, and other vegetables obtained in the areas adjacent to Fukushima and prohibited shipping of these food substances. On 23 March, the government advised avoidance of some vegetables from certain areas, and this was followed by the tragic news of the suicide of a farmer in Fukushima the next day. Iodine-131 is accumulated by the thyroid and raises the risk of thyroid cancer. People wanted iodine pills in order to prevent accumulation of iodine-131 in their thyroid glands. A rumor got abroad that ingestion of a small amount of gargle containing iodine would work. Experts announced that ingestion of gargle would be ineffective, as it is potassium iodine that is needed, not povidone-iodine which actually can even be harmful. We had become cautious about groceries. My friend pointed out, “If the food goes bad, we can smell it or see it. Radioactive substances are odorless and invisible. That really scares me.” Many areas were hit hard by harmful rumors. Although no radioactive substances were detected, groceries from the areas close to the power plants often stayed on the shelf. My wife told me that grocery stores should put donation boxes on the shelves next to the groceries from these areas. Some volunteers set up produce stands to help farmers harmed by these rumors. A questionnaire found that 75% of people are willing to buy groceries from the afflicted areas if their radioactivity is below the limits. On 23 March, radioactivity was detected at the water purification plant in Tokyo. Tokyo officials temporarily recommended that tap water not be used to prepare food for infants. We found that all bottled water was sold out. My friends keep tap water for several days before use. Theoretically, this should work, as iodine-131 is relatively short-lived (with a half-life of about 8 days) and tap water remains sterile because of the chlorine used for disinfection. Many doctors, including me, were desperate for information about radiation and health problems. Even though we live in a country with 55 nuclear power plants, we were ignorant. Soon after the accident, Masayuki Nakayama of Fukushima Medical University sent us an educational video via the mailing system of the Japanese Association of Dialysis Physicians (JADP). Dialysis patients and doctors were concerned about the dialysis water. Tadao Akizawa, president of the Japanese Society for Dialysis Therapy, and Chikao Yamazaki, president of the JADP, announced today that contamination of dialysate with radioactive substances and internal exposure of dialysis patients are very unlikely. This was really reassuring to us. Seiichi Matsuo, professor of nephrology and director of University of Nagoya Hospital, established an emergency medical assistance team composed of doctors from three national universities for continuous support of evacuation centers at Minami-Sanrikucho, one of the cities most severely damaged by the tsunami, and I went there as a member of the team. That city was attacked by a 50-foot-high tsunami, and most of it was completely ruined. Many citizens were dead or missing, and half of the citizens still stayed in 50 evacuation centers. We took a radiation counter with us, but as the closest distance to the Fukushima nuclear power plant on our way was 30 miles, we did not detect a significant increase in radiation. When we got into the town, there was almost nothing left. There I found the municipal office, or what remained of it. When the tsunami was coming, Miki Endo, a 24-year-old female city official, had grabbed a microphone and broadcast to citizens until the last moment to evacuate this building. When the furious tsunami reached the building, her voice stopped, and her body is still missing. There was no electricity, water, or gas supply in the city. One day before our arrival, an emergency medical support team from Israel had come to the city, and they allowed us to perform X-ray examinations and blood analysis at their tentative prefabricated hut. We provided medical care to evacuees with diabetes, hypertension, wounds received during clearance of debris and rubble, and other problems. Shortage of drug supplies was obvious, and blood pressures were high in many citizens on account of stress and lack of sleep (sleeping at evacuation centers is no fun). My fellow orthopedist was performing a physical examination of a man with a wound in his thigh caused by driftwood during the tsunami. He realized that all the skin below the patient’s knee was peeled off. He asked why, and the man explained, I was hanging on to a tree during the tsunami. Someone was swept up and clung to my leg. The person was finally swept away again, but because of the deadly grasp to my leg, my skin was peeled off with him or her. I could not do anything about it, as all I could do was to hang on to the tree for my life. Food aid had been delivered, including Meals Ready to Eat (MREs) from US forces, and we used water delivered by water trucks. Because of lack of electricity, evacuees had to start cooking with firewood at sunrise, and clean up all the dishes before sunset. This meant that we had brunch at 10:00 AM and dinner at 4:00 PM at the evacuation center. A doctor who had been to the city told me, “Canned and preserved food is very salty, and you may want sweets.” So I took a lot of chocolates and cookies from Tokyo with me. However, I found that many chocolates and cookies had already been brought in by others at the base camp on the way to Minami-Sanrikucho. During my stay, we still had many aftershocks. For the first time in my life, I heard the earth rumbling. It was scary to hear low-pitched earth sounds preceding earthquakes while in a sleeping bag. The citizens told us that the evacuation centers would be all right if there was another attack, as they had remained safely there during the mega-disaster. We came back to Tokyo at 2:30 AM on 3 April, Sunday. On 4 April, Tokyo Electric Power Company (TEPCO) started dumping the radioactive water of the Fukushima nuclear power plant into the sea with the approval of the government. This was an abrupt move without prior notice, and people felt very bad for themselves and neighboring countries. Fishermen were angry at this decision, and to our surprise, even the minister of agriculture, forestry, and fisheries had not known about the dumping beforehand. However, experts explained that contamination of fish was unlikely because the sea and streams dilute radioactive substances. Furthermore, the enrichment factor of radioactive substances is much lower than that of other toxic substances such as mercury and polychlorinated biphenyl (PCB). On 5 April, Japanese authorities reported the detection of unusually high levels of radioactive materials in fish caught about 50 miles from the stricken nuclear plant. The contamination was probably due to radioactive substances released before the intentional dumping; nonetheless, it was contrary to expectations. People kept talking about various methods to remove radioactive substances in tap water, including boiling, charcoal, activated charcoal, and hollow-fiber filters. On 6 April, the National Institute of Radiological Sciences verified various methods and announced that only reverse osmosis was effective for the removal of iodine-131 in water. Some Japanese nephrologists could not attend the World Congress of Nephrology in Vancouver. Toshio Miyata, executive council of the ISN and director of United Centers for Advanced Research and Translational Medicine of Tohoku University Graduate School of Medicine, could not deliver his plenary talk, because he had to remain home at his institute. Donations were contributed at the booth of the Japanese Society of Nephrology (JSN) during the meeting, and an auction was held at the presidential dinner. I was really touched by the auction, at which world-leading nephrologists donated and bid their belongings. Hirofumi Makino, president of JSN, participated and thanked Bernardo Rodriguez-Iturbe and other members of the Society for their overwhelming courtesy on behalf of all Japanese nephrologists and patients. The authorities had ordered people living within a 12-mile radius of the plant to evacuate, and recommended that people remain indoors or avoid an area within a radius of 18 miles. Although the evacuation zones had been concentric circles around the plant, the distribution patterns of radioactive substances depend on both the winds and the release intensities from the reactors. On 11 April, the government decided to expand the zone to certain communities beyond those areas on the basis of radiation readings. While rumors of the dangers of radiation continue to swirl, many locals are even more afraid that rumors will destroy their businesses and any hope of rebuilding their communities in Fukushima. Since rumors were so prevalent, not only were the farming and fishing industries affected, but other industries were damaged as a result of claims that even parts and machines might be contaminated. On 12 April, the Japanese Nuclear and Industrial Safety Agency announced that the severity level of the nuclear accident was now 7. This is the worst on the International Nuclear Event Scale, the same level as Chernobyl in 1986, which no other accident had attained since then. However, the general view is that the raising of Fukushima to a level 7 accident does not mean that the situation at Fukushima is worsening. The government just explained that the escalation of the level was based on re-analysis of the accumulating data. The delay of one month in acknowledging the extent of the accident made some citizens suspicious as to whether the authorities had intentionally delayed or blocked the release of information. In spite of the escalation of the level by the government, experts agree that Fukushima is not another Chernobyl. Up to now, only about a tenth of the radiation released in Chernobyl escaped the damaged Fukushima plant. The way the radiation has been released is also different. The Chernobyl fire put a lot of radioactive substances into the atmosphere, whereas radioactive substances released by the Fukushima accident derived mainly from venting gas from the reactor and the release of cooling water. In the month following the Chernobyl explosion, 134 workers were hospitalized with acute radiation sickness and 31 died, whereas in Fukushima, only three workers were hospitalized with minor injury, and none died from radiation exposure. Obviously contradictory reports are released by the media, TEPCO, and the government. On the one hand, officials insist that safe limits for radiation in food are kept extremely low, and that people should not be unduly worried by reports about radiation. In contrast, journalists report that the government is downplaying the fact that radiation leakage has been massive and say that the threat to public health has been underestimated. The government set its initial severity rating of the nuclear accident at level 4 on an international scale on 12 March. On 18 March, the government changed its outlook and announced that the accident was level 5. The rating was eventually raised to level 7 more than 20 days after the second assessment. In contrast, from the beginning, the Nuclear Safety Authority of France and the Institute for Science and International Security of the United States suggested that the level might be 6. Journalists insist that this represents downplaying and underestimation. Studies were reported on the website of the JADP on 13 April showing that treatment of water with activated charcoal followed by reverse osmosis reduces contamination of radioactivity such as cesium-137, cesium-134, and iodine-131 to below detection limits. The results verified the immediate reassurance about the safety of the dialysis water by Tadao Akizawa and Chikao Yamazaki on 24 March. A group of Japanese doctors proposed storage of blood stem cells of workers at the Fukushima nuclear plant as a safeguard (T. Tanimoto et al., Lancet advance online publication, 15 April 2011, doi:10.1016/S0140-6736(11)60519-9). On 16 April, the government announced that the health conditions of the workers would be followed for over 30 years.