Thursday, October 27, 2011

Lifetime Cumulative Limit of Internal Radiation from Food to Be 100 Millisieverts in Japan

That's the formal recommendation of the experts on the government's Food Safety Commission.

External radiation is not counted in this number, as opposed to their draft plan in July which did include external radiation, and it is in addition to the natural radiation exposure (by which is meant pre-Fukushima natural).

The experts on the Commission didn't rule on the radiation limit for children, leaving the decision to the Ministry of Health and Labor as if the top-school career bureaucrats in the Ministry would know better.

Yomiuri and other MSMs are spinning it as "tightening" the existing provisional safety limits on food.

From Yomiuri Shinbun (10/27/2011):


The Food Safety Commission under the Cabinet Office has been deliberating on the health effect of internal radiation exposure from the radioactive materials in food. On October 27, it submitted its recommendation to set the upper limit on lifetime cumulative radiation from food at 100 millisieverts.


On receiving the recommendation, the Ministry of Health and Labor will start setting the detailed guidelines for each food items. They are expected to be stricter than the provisional safety limits set right after the Fukushima I Nuclear Plant accident. The Radiation Commission under the Ministry of Education will review the guidelines to be set by the Ministry of Health and Labor, and the new safety limits will be formally decided.


According to the draft of the recommendation in July, the Food Safety Commission was aiming at setting "100 millisieverts lifetime limit" that would include the external radiation exposure from the nuclides in the air. However, based on the opinions from the general public, the Commission decided that the effect of external radiation exposure was small and focused only on internal radiation exposure from food.


If we suppose one's lifetime is 100 years, then 1 millisievert per year would be the maximum. The current provisional safety limit assumes the upper limit of 5 millisievert per year with radioactive cesium alone. So the new regulations will inevitably be stricter than the current provisional safety limits.


In addition, the Commission pointed out that children "are more susceptible to the effect of radiation", but it didn't cite any specific number for children. The Commission explained that it would be up to the Ministry of Health and Labor and other agencies to discuss" whether the effect on children should be reflected in the new safety limits.

Oh boy. So many holes in the article.

First, I suspect it is a rude awakening for many Japanese to know that the current provisional safety limits for radioactive materials in food presuppose very high internal radiation level already. The Yomiuri article correctly says 5 millisieverts per year from radioactive cesium alone. The provisional safety limit for radioactive iodine, though now it's almost irrelevant, is 2,000 becquerels/kg, and that presupposes 2 millisieverts per year internal radiation. From cesium and iodine alone, the provisional safety limits on food assume 7 millisievert per year internal radiation.

(The reason why the radioactive iodine limit is set lower than that for radioactive cesium is because radioactive iodine all goes to thyroid gland and gets accumulated in the organ.)

I am surprised that Yomiuri even mentioned the 5 millisieverts per year limit from cesium exposure alone. I suspect it is the first time ever for the paper.

Second, the article says the Commission decided to exclude external radiation from the "100 millisieverts" number because of the public opinion. Which "public" opinion are they talking about? Mothers and fathers with children? I doubt it. If anything, the general public (at least those who doesn't believe radiation is good for them) would want to include external radiation so that the overall radiation limit is set, rather than just for food.

Third, and most importantly, if the proposed lifetime limit of 100 millisieverts is only for internal radiation from FOOD, then the overall internal radiation could be much higher. Why? Because, pre-Fukushima, the natural internal radiation from food in Japan was only 0.41 millisievert per year (mostly from K-40), or 28% of total natural radiation exposure per year of 1.45 millisievert (average). Of internal radiation exposure, inhaling radon is 0.45 millisievert per year in Japan, as opposed to the world average of 1.2 millisievert per year.

Now, these so-called experts in the government commission are saying the internal radiation from food can be 1 millisievert per year (assuming the life of 100 years), in addition to the natural internal radiation from food (K-40) which is 0.41 millisievert per year. Then, you will have to add internal exposure from inhaling the radioactive materials IN ADDITION TO radon which is 0.45 millisievert per year.

Winter in the Pacific Ocean side of east Japan is dry, particularly in Kanto. North wind kicks up dust, and radioactive materials in the dust will be kicked up. The Tokyo metropolitan government will be burning away the radioactive debris from Iwate Prefecture (Miyagi's to follow) into the wintry sky. So-called "decontamination" efforts all over east Japan will add more radioactive particles in the air for people to breathe in.

Don't be fooled by this 100-millisievert lifetime number. It's bogus.

For your information, the comparison of natural radiation exposure levels (the world vs Japan), from the Nuclear Safety Research Association Handbook on treating acute radiation injury (original in Japanese; my translation of labels). Japan has (or had) markedly lower radon inhalation than the world average, and much lower external radiation from the ground and from cosmic ray. It makes it all up by overusing the medical X-rays and CT scans, and even the Nuclear Safety Research Association who issued the following table says Japan tends to use too many X-rays and scans and that the medical professionals should make effort not to overuse them.

Type of exposure
World average
(UN Science Commission)
Japan average
Natural radiation
From ground
Cosmic ray
Ingestion (K-40, etc)
Inhaling radon
Artificial radiation
World average
Industrial nations
Medical X-ray, CT
Dental X-ray
Nuclear medicine diagnostics


Anonymous said...

There is no way to directly measure INTERNAL radiation.

There are only WildAssGuesses, assumptions and Bernaysian* fogs to yield any desired outcome desired by pseudoscientist academics and public-relations.

*Bernays was American father of modern, psychological population control.

Internal alpha and most beta will not penetrate outwardly thru tissue/bone to impinge on any instrumentation. Only some beta and nearly all gamma can be directly detected and measured from outside the body.

Anonymous said...

The average bomb survivor from Hiroshima got 20 mSv??!!!

What the hell is the Japanese government thinking?

Sebaschan said...

Well at least it would be good to know that they might have to set a lower limit for food. You can measure air radiation and protect yourself by not going into contaminated areas, like Tokyo...but food is something that will be sold all over Japan, mixed with other lower contaminated food and its origin will be disguised...
For me planning on working in Japan for the next 2 years starting in April, a lower radiation limit for food is crucial. If it's not set to a reasonable limit soon I'll have to replan my whole life...

kintaman said...

Can anyone look at Japan and what is happening in total and not realize that it is finished. Japan is done for. Not only has this accident been such a disaster but the government's handling has made it even worse.

They should have strictly quarantined everything around the Fukushima area and buried all contaminated materials. But no....they wanted to destroy the entire nation. Well congratulations you f*cking idiot monsters.

Bekrl said...

The Japanese MUST take action now and at least make sure that the children nation wide are eating imported food. The month I left Japan with my wife and kids, the paper reported that radioactive beef had been sold to school kids in the prefecture I lived in (central Japan).

Japan imports up to 70% of their food anyways... if they want to do something worthwhile now to save their future (and history) they must feed their kids with imported food.

Anonymous said...

The Japanese approach is to pretend all is good. If radiation is higher than expected, raise the level or create a standard that you cannot effectively measure.

It really defies logic how the government is so hell bent on feeding the population with irradiated food. There is a website saying that EU (Emergency) food irradiation levels is same as current day Japan. But the difference is that EU will not be shipping food, water, soil, waste etc. to uncontaminated land and feed the population.

Some one's blog on 2000 bg/kg in food:
(primavera, did you cover this story before?)

Anonymous said...

The recent IAEA report on the October visit by the IAEA implies radionuclides in incinerated waste will be trapped by filters in "municipal solid waste incinerators equipped with electro-static precipitators." I have no idea how to assess the claim (found by a google search) by the energy industry that these precipitators can actually remove 75-90% of radionuclides.

Anonymous said...

We will know when we start to measure? Not the best way to find out but I guess that is the approach so far. Lets say we talk again in 30 years and hope for the best.

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