The mounting human costs of Japan’s nuclear disaster 日本核災損失超大...

The mounting human costs of Japan’s nuclear disaster 日本核災損失超大...

Radiation in Japan

Hot spots and blind spots

Oct 8th 2011 | IITATE | from the print edition

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CREST the hill into the village of Iitate, and the reading on a radiation dosimeter surges eightfold—even with the car windows shut. “Don’t worry, I’ve been coming here for months and I’m still alive,” chuckles Chohei Sato, chief of the village council, as he rolls down the window and inhales cheerfully. He pulls off the road, gets out of the car and buries the dosimeter in the grass. The reading doubles again.

Iitate is located 45km (28 miles) from the Fukushima Dai-ichi nuclear power plant hit by a tsunami on March 11th this year. In the mountains above the town, the forests are turning the colour of autumn. But their beauty is deceptive. Every time a gust of wind blows, Mr Sato says it shakes invisible particles of radioactive caesium off the trees and showers them over the village. Radiation levels in the hills are so high that villagers dare not go near them. Mr Sato cannot bury his father’s bones, which he keeps in an urn in his abandoned farmhouse, because of the dangers of going up the hill to the graveyard.

Iitate had the misfortune to be caught by a wind that carried radioactive particles (including plutonium) much farther than anybody initially expected after the nuclear disaster. Almost all the 6,000 residents have been evacuated, albeit belatedly, because it took the government months to decide that some villages outside a 30km radius of the plant warranted special attention. Now it offers an extreme example of how difficult it will be to recover from the disaster.

That is mainly because of the enormous spread of radiation. Recently the government said it needed to clear about 2,419 square kilometres of contaminated soil—an area larger than greater Tokyo—that received an annual radiation dose of at least five millisieverts, or over 0.5 microsieverts an hour. That covered an area far beyond the official 30km restriction zone (see map). Besides pressure- hosing urban areas, this would involve removing about 5cm of topsoil from local farms as well as all the dead leaves in caesium-laden forests.

However, Iitate’s experience suggests the government may be underestimating the task. Villagers have removed 5cm of topsoil from one patch of land, but because radioactive particles continue to blow from the surrounding trees, the level of radiation remains high—about one microsievert an hour—even if lower than in nearby areas. Without cutting down the forests, Mr Sato reckons there will be a permanent risk of contamination. So far, nobody has any idea where any contaminated soil will be dumped.

The second problem is children’s health. On September 30th the government lifted an evacuation advisory warning to communities within a 20-30km radius of the plant. The aim was partly to show that the authorities were steadily bringing the crippled reactors under control.

But these areas are still riddled with radiation hot spots, including schools and public parks, which will need to be cleaned before public confidence is restored. Parents say they are particularly concerned about bringing their children back because the health effects of radiation on the young are so unclear. What is more, caesium particles tend to lurk in the grass, which means radiation is more of a risk at toddler height than for adults. In Iitate, Mihori Takahashi, a mother of two, “believes only half of what the doctors say” and says she never wants to bring her children back. That, in itself, may be a curse. “The revival of this town depends on the children returning,” says Mr Sato.

And even if people return, Mr Sato worries how they will make a living. These are farming villages, but it will take years to remove the stigma attached to food grown in Fukushima, he reckons. He is furious with Tokyo Electric Power, operator of the plant, for failing to acknowledge the long-term impacts of the disaster. He says it is a way of scrimping on compensation payouts.

One way to help overcome these problems would be to persuade people to accept relaxed safety standards. A government panel is due to propose lifting the advisory dose limit above one millisievert per year. This week in Tokyo, Wade Allison, a physics professor at Oxford University, argued that Japan’s dose limit could safely be raised to 100 millisieverts, based on current health statistics. Outside Mr Sato’s house, however, a reading of the equivalent of 150 millisieverts a year left your correspondent strangely reluctant to inhale.