Thursday, December 15, 2011

Japanese Government Decides 20 Millisieverts Annual Radiation Exposure Poses Little Cancer Threat to General Public

While the entire nation and the entire world wait with bated breath for the declaration by the Japanese national government of a cold shutdown of Fukushima I Nuclear Power Plant (to be exact, as NY Times correctly reported on December 14, "state of a cold shutdown") later in the evening of December 16 Japan Standard Time, the working group of government radiation experts has declared that:

  • Annual radiation exposure of more than 100 millisieverts is known to raise risks for developing cancers, but nothing is known about annual radiation exposure of less than 100 millisieverts;

  • Annual cumulative radiation exposure (external only, it seems) of 20 millisieverts for the general public poses hardly any danger of developing cancer;

  • There is no difference between internal and external radiation exposure;

  • Low-dose radiation exposure over a long period of time is less risky than one-time episodic exposure to large-dose radiation;

  • The relationship between low-dose internal radiation exposure and bladder cancer cannot be proven.

Above points are from the article in Mainichi Shinbun 12/15/2011, the only paper that had any critical thinking on this issue. All the other large-circulation newspapers and NHK simply parroted what was said by the experts and the government officials.

Speaking of government officials, Asahi Shinbun reports (12/15/2011) that Minister in charge of the nuclear accident and Minister of the Environment Goshi Hosono explained the government's thinking in the press conference after the group meeting, saying:


"So, 20 millisieverts per year radiation means people can live there."

This working group of so-called experts met for about a month to discuss the risk of "low-level" radiation exposure (meaning less than 20 millisieverts per year) and make a decision. Now they have made the decision and submitted the report to the government, the government duly accepts the independent experts' opinion, declares 20 millisieverts radiation to be an acceptable guideline, and plan accordingly.

What's the plan, you ask?

The government is set to convene a cabinet meeting in the evening and declare a "cold shutdown state" and will soon declare certain municipalities within the 20-kilometer radius "no entry" zone to be now "safe" to return (see my previous post).

In that country, if the government declares "one plus one equals four", or "tomorrow the sun rises from the west", people are expected to say "of course", and the calculators would start showing one plus one equals 4 and the sun would rise from the west. Or at least they would try. The land of miracles.

20 millisieverts per year of radiation exposure for the general public. There is no mention of different standard for children, except for the "effort" that the government is supposed to exert to lower the radiation for children.

Radiation control zone is 1.3 millisieverts per 3 months (5.2 millisieverts per year).


Anonymous said...

Does anyone know how many Tepco employees experienced 20 millisieverts cumulative during the year prior to the meltdowns, working in and around the reactors?

arevamirpal::laprimavera said...

Probably zero. Workers hired by the maintenance subcontractors, probably not in one year.

Anonymous said...

>to discuss the risk of "low-level" radiation exposure (meaning less than 20 millisieverts per year)

low level is anything under 100 mSv

Mauibrad said...

Re: "There is no difference between internal and external radiation exposure"

That's absolute, utter B.S.

Vivre said...

Fukushima Safety Level NOT SAFE! -

a worth reviewing analysis of various research studies and available sourcelinks

Anonymous said...

Thanks to Vivre for posting the Fukushima Safety Level NOT SAFE video. It shows unequivocally that 5 millisieverts and over per year causes cancer. To say, like the government does, that "nothing is known" is a blatant bald faced lie to be lapped up by the sheeple for breakfast. But then even some in the government admit noone believes the government! WAR IS PEACE WAR IS PEACE WAR IS PEACE...

Yosaku said...


Many parts of the world have radiation in excess of 5 millisieverts per year.

Also, that video is horrible. They've made the common mistake of defining "safe" in such a way that nothing is safe. For example, walking would be extremely dangerous by their definition (about 4,000 pedestrians are killed every year in the US alone).

Atomfritz said...

I never believed before that a democratic country would do such. In the European Union the limit is (still) 0.1 mSv/a.

Just replace "democratic" with capitalist, then it might work out.
It's all a matter of money.
As long as the prevention of property loss outweighs the (hidden) body count financially, it will be "safe".
At least the rich can (and will) move elsewhere where it's cleaner.

Anonymous said...


In the EU the limit is also 1 mSv/year without including medical radiation. And that's in non-emergency situations, wait until there's a big accident in Europe and you would see how fast the safety levels go up. Or do you think anyone was evacuated from the contaminated areas in Sweden, Norway, Austria, etc. after Chernobyl?

Anonymous said...

Actually, the EU's normative implies that they would follow the same approach as the Japanese have:

Bands of reference levels for public exposure
1. The optimisation of public exposures in emergency and existing exposure situations shall
be based on a reference level to be established within the following bands, expressed in mSv
effective dose (acute or annual):
(a) greater than 20 and less or equal to 100
(b) greater than 1 and less or equal to 20
(c) 1 or less"

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