The Economist: Oxford Professor Says OK to Raise Annual Dose Limit by 1000 Times for the Japanese, But the Reporter Reluctant to Inhale

the air in Iitate-mura, 45 kilometers from Fukushima I Nuclear Power Plant. The Economist article mentions Oxford Professor Emeritus Wade Allison in passing toward the end, and that is more interesting than the article itself, which is nonetheless copied below. (Scroll down to Professor Allison's thinking presented below the article.)

The Economist's article on October 8, 2011 titled "Hot spots and blind spots":

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.

Dr. Wade Allison is professor emeritus of physics (particle physics) at Oxford University. The event that the Economist's reporter refers to in the article must be the talk given at American Chamber of Commerce in Japan (ACCJ) on October 3, where the professor, along with another researcher, presented the strong case that the radiation exposure below 100 millisieverts per year was not a problem, if one only gets rid of the unreasonable fear of radiation. He also says the current food regulation, evacuation regulation are "unreasonable" and should be relaxed significantly.

Here's the screen capture of a page from his presentation slides he used in the ACCJ talk:

He criticizes the ICRP recommendation for radiation dose, and suggests we ditch the ICRP's "As Low As Reasonably Achievable (ALARA)" and adopt "As High As Relatively Safe (AHARS)".

And what is his AHARS level recommendation? His recommendation seems to be based on the therapeutic, targeted doses used in cancer treatment. Here's his slide page 17:

• 100 mSv max single dose

• 100 mSv max in any month

• 5000 mSv max lifelong

100 millisieverts max in any month makes the annual limit of 1,200 millisieverts, or 1.2 sievert. Professor Allison must think that level is an emergency level, as he puts the lifelong max at 5 sieverts.

There you go, Japanese government. Just wholeheartedly embrace the professor's recommendation, and you don't need to do a thing. No decon, no health monitor, no compensation to pay. Even in Okuma-machi and Futaba-machi in Fukushima right outside the plant, everyone can live happily at least for 5 to 10 years at least till they exceed 5 sieverts max for the lifetime. Fuku-I plant workers can continue to work at the plant much, much longer. No one has reached 1.2 sievert yet.

(Why did the American Chamber of Commerce in Japan invite Professor Allison? What was the purpose? Does anyone know?)

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