Being reported by many sources, including:
At issue are updated government guidelines that allow schoolchildren to be exposed to radiation doses that are more than 20 times the previously permissible levels. That dose is equal to the international standard for adult nuclear power plant workers.
(I'd earlier blogged about the top radiation advisor who resigned in protest over this decision).
As ABC writes, the government position is one of perceived necessity: contamination is widespread enough that the old 1 mSv/year would demand an exodus.
The government says it had no choice but to raise the legal exposure limit, saying about three-quarters of the schools in Fukushima have radiation levels above the old safety level of one millisievert.
I'm not even aware of a map at this resolution: the ones available (like in my previous post) stop at 5 mSv/year external dose, which already covers a very wide area.
Like a sacrificial offering to an angry mob, an education ministry official was bundled outside to speak to the demonstrators, although he had very little to offer them at all.
The hapless official's words only seemed to anger the protesters further.
"The current radiation levels for schools in Fukushima pose no health risks to kids at all," the official said.
I find it bizarre that the government is claiming external doses of tens of mSv -- at the level of CT scans, or possibly several CT scans -- are absolutely risk-free. While there's little empirical data at this level, it's widlely believed that doses these high cause nonzero excess risk of cancer and cancer fatalities. See for instance an authoritative reference from a radiological professional society -- these for adult doses:
This is a very messy situation. The high radiation levels in parts of Fukushima are, apparently, likely to cause cancer deaths. And this excess risk is relatively small compared to other risk factors. So how does one react to this? Should government apply ordinary risk-tolerance standards, doing nothing, and allow a few tens or perhaps hundreds of radiation deaths (epidemiologically undetectable)? Or should they mount a massively expensive and destructive evacuation effort over a large area (the 5 mSv/year external dose range currently encompasses about 1 million people), itself probably causing serious health hazards to the displaced? Or should it leave people to make their own risk judgements (whether rational or not), informing them of the situation accurately?
(One of the commenters on this blog suggested, correctly, that to evacuate at this risk level, one should equally evacuate most cities near fossil fuel plants, factories, major highways. Which is strictly accurate, if you weigh all risks equally without regards to source. But then it does not seem people choose to view radiation dangers in the same way as other dangers.)
What I think they should not be doing is denying the problem like the Japanese officials are at this point. This is either incompetent or unconscionable.
From some extrapolations of future dose (over more than one year), see the new ISRN report (pdf, in French). In my previous post I also made a graph charting the decay of dose rates from cesium. (Other isotopes are mostly decayed away at this point).