WSJ; AUGUST 16, 2011
Murky Science Clouded Japan Nuclear Response
By YUKA HAYASHI
IITATE, Japan—After a third explosion rocked Japan's Fukushima Daiichi nuclear complex on March 15, the weather took a worrisome turn. A wind that had been blowing steadily out to sea shifted to the northwest, carrying plumes of radiation up a river known locally as the "corridor of wind." That evening, a late-winter snow began falling on this mountain village. Residents awakened the next day to a blanket of white over their homes, roads, cow pastures and pine forests. They stepped outside and began shoveling.
Back in Tokyo, officials had information suggesting that the snow carried radiation to this community 17 miles from the stricken plant, well outside the government's evacuation zone. Nevertheless, a week passed before government officials gave residents any clear indication that their town of 6,000 had become a nuclear "hot spot," and even then they were hesitant to order residents to get out. "We spent a lot of time debating because we knew we were making a very profound decision," says Toshimitsu Honma, a member of the Nuclear Safety Commission's emergency committee and deputy director general at the Nuclear Safety Research Center, a government agency.
Some young people in the village who were tuned in to Internet chatter about contamination grew frustrated. In late March, Kenta Sato, 29 years old, turned to his new Twitter account, sending hundreds of dispatches from his smartphone. He attracted 5,700 followers, including several members of Parliament. "Since the government won't issue an evacuation order despite constantly high radiation levels, I have to keep working in a place where radiation comes falling down all day long," he wrote on March 26. "Please help!"
Tracking the Clouds
As Japan's nuclear crisis intensified, some 700 people stayed at an elementary school in Karino, even as government projections suggested that radiation was heading their way. See a timeline of events, and the projections available to government officials.
Japan Real Time
A Wall Street Journal examination of what happened in Iitate shows how challenging it can be to assess the dangers of fallout. Deciding to evacuate towns closer to the plant, where fallout was heavier, was a relative no-brainer. But radiation measurements taken at dozens of locations around Iitate differed widely, and science didn't offer a clear answer for whether the measured amounts were too much. In the end, it took government officials more than a month to decide that Iitate was too dangerous to inhabit. And by then, many residents, particularly older ones, didn't take the warnings seriously.
Confusion over what to do about radioactive contamination is playing out in various forms all over Japan. Officials are struggling to figure out where it is safe to live, what is safe to eat and how farmers decontaminate their fields. At present, 116,000 people remain unable to return to their homes due to the radiation threat. Even as the government continues to ask more people to evacuate, it is mulling allowing others to return to towns where contamination is relatively light.
While high levels of radiation are unequivocally dangerous, the science regarding health effects of the kind of lower-level contamination that has spread far from the plant is surprisingly hazy. There is no clear-cut scientific consensus on what level of fallout should trigger mandatory evacuation, or on how long-term exposure to radiation at the levels being measured in places like Iitate affect health. Further muddying the picture, the spread of radiation has been fiendishly unpredictable, skipping some areas and showing up in concentrated hot spots elsewhere.
For the first few days after the March 11 tsunami crippled the Fukushima Daiichi plant, authorities were confronted with a succession of frightening explosions and fires. The government ordered everyone living within 12.4 miles of the plant to evacuate, and those between 12.4 and 18.6 miles to stay indoors. Residents of Iitate and other towns outside these zones had a sliver of good fortune: a steady wind was carrying the radiation out to sea.
The wind shift on the afternoon of March 15 erased that advantage. Back in Tokyo, a government computer system called Speedi was crunching weather data to predict how radioactive emissions would spread. After the wind shift, it forecast that contamination was heading toward Iitate.
By the next day, the ministry of education and science, which oversees nuclear research, had sent a team to Nagadoro, a hamlet in the southern part of Iitate, to monitor radiation. Soon other teams arrived from elsewhere in Japan. They drove specially equipped vans with radiation sensors mounted to the roofs. Before long, they were monitoring the air in 36 separate spots around Iitate.
The government posted radiation data online, but it provided no interpretation. When Mr. Sato heard about contamination from other young residents, he left town to stay with his mother two towns away. But on March 21, his father decided to reopen a small business he owns that cleans metal molds used to make concrete blocks. He asked all six of his employees, including his son, to report back to work. Feeling trapped, Mr. Sato began pressing for the government, via Twitter, to evacuate the village.
At the Nuclear Safety Commission, the government's nuclear-policy advisory body in Tokyo, Mr. Honma was monitoring data from Iitate and surrounding communities. The prefecture government had reported high levels of radiation in the air in Iitate as early as March 15. Mr. Honma says he became convinced that the area had received sizable doses of radiation.
But whether those doses were sufficient to warrant evacuation was another matter. Very high radiation doses, such as from an atomic bomb, can burn, poison or kill. But the effects of smaller doses aren't nearly as clear. In theory, any exposure to radioactive elements raises the risk of cancer, especially in young children. But the effects of slight increases are difficult to measure, particularly because about 40% of people eventually get some form of cancer under normal circumstances, according to the National Cancer Institute in the U.S.
Human radiation exposure is measured in units called sieverts. A chest X-ray delivers a dose of about 0.04 millisieverts, and traveling from New York to Tokyo by plane, where cosmic rays are higher than on the ground, comes in at 0.07 millisieverts. Such natural and man-made sources add up to around 3 millisieverts per year for the average U.S. resident, the Environmental Protection Agency estimates.
Many experts contend that a dose of 100 millisieverts raises the risk of cancer by 0.5%—no matter how long the time period over which it is absorbed. The International Commission on Radiological Protection, an independent international body, recommends immediate evacuation of people at that level. The U.S. Nuclear Regulatory Commission says there is no hard evidence linking health problems to doses below 100 millisieverts.
Yuka Hayashi/The Wall Street Journal
Japanese government guidelines stipulated that residents should be evacuated once doses of accumulated radiation exceed 50 millisieverts. For exposures of 10 to 50 millisieverts, the guidelines said, they should be told to stay indoors.
Radiation levels in Iitate peaked on March 17 and 18, then began falling, Mr. Honma says. But because the radiation wasn't gone, the overall accumulated dosages continued to climb. At one of the town's hot spots, the accumulated dose was 28 millisieverts through March 28, according to the Nuclear Safety Commission, which projected that it would eventually reach 35.
Toshiso Kosako, a radiation-safety specialist who was then a special adviser to Prime Minister Naoto Kan—he resigned in late April to protest the government's handling of the crisis—urged Mr. Kan's cabinet on March 22 to classify parts of Iitate and surrounding towns as "highly contaminated zones." In a document submitted to senior government officials, he said that radiation monitoring needed to be beefed up, that childhood thyroid cancer was a risk. In another document two days later, he urged the government to consider expanding the evacuation zone to include those communities.
With no consensus among its experts, the Nuclear Safety Commission didn't prod the government to expand the zone to include Iitate. "We are aware that there are some areas outside [the evacuation zones] that are contaminated, but it is our judgment that there won't be health consequences as a result," Haruki Madarame, the commission's chairman said.
Yuka Hayashi/The Wall Street Journal
Mr. Sato's own father, Koichi, continued to drink tap water and eat vegetables grown in local gardens. His father's elderly mother and five dogs stayed put in Iitate, too. One morning, he opened his windows to let in the spring air, triggering a shouting match with his son, who by then was carrying a compact radiation monitoring tool.
"I understand why young people may be worried, but in 20 years or 30 years, I'd be dead anyway, whether I get cancer from radiation or not," says the elder Mr. Sato, who is 57. He says he can't leave his company and moving it isn't an option.
The government sent several radiation experts to Iitate to talk to residents. On March 25, Noboru Takamura, a physican and Nagasaki University professor, told about 600 villagers that they could continue to live safely in Iitate if they took precautions like wearing face masks outdoors and washing hands frequently, according to the village newsletter. Mr. Takamura said recently that radiation readings in the village were below 100 millisieverts—considered the threshold for health risk.
On March 28, a group of independent experts led by Tetsuji Imanaka, an associate professor at Kyoto University's Research Reactor Institute and an opponent of nuclear power, visited Iitate to test the air and soil. The group took readings at more than 150 locations. At one spot, radioactivity was high enough that someone who stood there 24 hours a day would be exposed to an accumulated radiation of 160 millisieverts in a year—well above the 100 millisievert danger level. In other spots, readings were much lower.
"We saw grandpas and grandmas going about their lives in an environment that you'd only see in highly controlled areas at a nuclear-power plant," says Mr. Imanaka, who had spent years studying the aftermath of the Chernobyl nuclear accident.
He says his readings differed from the government's because his team tested different locations. "Some of those places had higher radiation levels, some as high as 2½ times the government figures," he says, adding that he doesn't think the government intentionally selected places with low dosages.
Before leaving Iitate, Mr. Imanaka advised Norio Kanno, the village chief, to evacuate children as soon as possible. Masuro Sugai, an economist in Mr. Imanaka's group, said the village chief was more interested in learning how to clean up contaminated soil so farmers could plant again. Mr. Kanno and other village officials declined to comment.
Doctors sent in by the government's Nuclear and Industrial Safety Agency tested thyroid glands of several hundred children in Iitate around the same time. They said everyone cleared the government standard. Critics said the results were skewed because the test was done more than two weeks after the accident, when radiation levels were declining.
As the days wore on, village elders grew resistant to any evacuation. In a letter submitted to the central government on April 9, Mr. Kanno, the village chief, complained that the government had released information about Iitate's contamination before consulting village officials, inflicting "immeasurable pain and stress" on residents.
Some young residents, including the younger Mr. Sato, criticize village officials for not taking the lead in evacuating people. "People in power—the village chief and assembly members—are all in their sixties and seventies and can't abandon the village," says Mr. Sato. "Because they are staying, children can't leave. These adults have become a burden on the young people."
On April 22, Tokyo finally ordered residents of Iitate and four other municipalities with similar hot spots to evacuate. The government cited a recommendation by the International Commission on Radiological Protection that once the emergency phase of a nuclear accident passes—it didn't specify when that point arrives—the exposure of local residents should not exceed 20 millisieverts per year.
Some in Iitate were in no hurry to get out. When village schools reopened for a new school year in mid-April in rented space in a neighboring town, roughly 400 children were still living in Iitate and had to be bused to the new locations. The village hall stayed open until June 22. Nine businesses have gotten permission to continue operating and let their workers commute in.
By last week, the only people still living in Iitate were 108 residents of a nursing home—the elderly were not required to evacuate—and 10 others who refused to budge, including Mr. Sato and his mother.
—Phred Dvorak contributed to this article.