Sunday, February 19, 2012

Prof. Yukio Hayakawa's Walk with his Survey Meter in Nagareyama-Kashiwa in Chiba Prefecture

流山-柏 garmin at EveryTrail

Radiation levels remain elevated in Kashiwa City in Chiba Prefecture. It was in Kashiwa that 450,000 becquerels/kg of radioactive cesium was found from the soil near the drain in the public space in the middle of the city. There is a strange (to me anyway) collaboration between the city and the citizen volunteers to decontaminate the city.

Before the Fukushima I Nuke Plant accident, the background radiation level in Kashiwa City must have been no higher than the average in Chiba, which was 0.03 microsievert/hour (see this site). Now, as Professor Hayakawa's walk shows, it is 10 times that in many locations. Contrary to a belief by some in Japan that there was no radioactive plume that went south from Fukushima through Ibaraki to Chiba, Tokyo and Kanagawa, these elevated radiation levels in Kashiwa City are the evidence that the plume did in fact come.


netudiant said...

This is an obvious consequence of the accident, that much of the Japanese homeland has been polluted. That will be a reality for the next several hundred years.
The only ray of light is that we know from the experience of other parts of the world, in China or Brazil or Iran, that the levels of contamination measured in Japan have no obvious impact on mortality. As cancer is already the cause of death for about 40% of all Japanese, the effect of Fukushima will be difficult to detect.

Anonymous said...

How many generations of people have lived in the high radiation areas in Brazil, Iran, India again? Do they have to inhale or ingest radioactive cesium?

Chibaguy said...

That is a ray of light for the nuke industry and government.

James said...


I enjoy reading your comments as you often have a scientifically astute perspective to add. However I have to question this comparison between nuclear accident contamination in Chiba and radon background radiation in Ramasar etc.

How many differences between the two situations are there which might make such comparisons scientifically dubious? The kinds of isotopes, the ratio of different contaminants, their half-lives, decay energies and decay chains, not to mention the physical particle size, environmental distribution and potential for bio-accumulation are all completely different.

In fact, why bring the thorium / uranium geology of China or Brazil or Iran into a discussion about cesium contamination at all when much more relevant research exists post Chernobyl? Surely it only serves to confuse the situation. Instead, why not start with (for example) the Swedish post-Chernobyl study by Tondel et. al? I know it has been the subject of subsequent debate, but surely it makes a much more logical point of departure for further study.


Anonymous said...

"As cancer is already the cause of death for about 40% of all Japanese, the effect of Fukushima will be difficult to detect.."

The most damning part is this:

1. Many people accept the high cancer rate as natural, they do not question why it is so high among Japanese, why it is increasing.

2. The government is using the high cancer rate as a political spin ("see, it's normal, we've always had a high cancer rate, it's not from Fukushima") and many many stupid people are buying it.

3. Even obvious contributing factors are now willingly ignored by the Japanese politicians and scientists alike, such as dispersion and burning of contaminated disaster debris in city incinerators all over Japan and refusal to control distribution and traffic of contaminated foods and materials.

It is astonishing that Japan, despite many scientists and nobel prizes, has decided to throw out of a window its own scientific data from Hiroshima and Nagasaki experience, and has chosen to trade the financial health of TEPCO and politicians over the life of its own people.

No other civilized countries than Japan act so hostile and inhumane to their own citizens, especially women and girls who might bear future Japanese children. Shame on you. --- This, from a Japanese woman.

arevamirpal::laprimavera said...

@anon at 9:17PM, the political class in Japan has pretty much spoken, hasn't it? that they do not want a future with healthy children. They don't seem to want any future at all as a nation.

There is a famous ancient Chinese poem from 1300 years ago, popular among Japanese. Opening in English would be something like:

"Nation is broken, nature remains"

People made a new poem out of this, saying:

"Nation is broken, TEPCO remains"

netudiant said...

Thank you James for a very relevant reference which I had not seen previously.
It is imho much superior data vis a vis that generated from within the former USSR, simply because the confounding variables are so much less. It is also more relevant than the experience in other high background areas because the impact of the added contamination can be timed cleanly.
The conclusions seem plausible, although the effect, about an 11% increased risk at a 100kiloBequerel/meter squared deposition, is small.
That said, radiation and cancer is a difficult subject. Afaik, the long term survivor studies of the A-bombing victims show slightly lower than average cancer rates.
However, it just seems common sense to minimize the dispersal of radioactive contamination. The unwillingness of the Japanese authorities to act on this front is surprising. Is it that they are concerned that a large portion of Japan might otherwise be permanently stigmatized as 'unclean'?

Anonymous said...

Cancer is the worst and perhaps least likely outcome. Why are we debating it? There are lots of potential other unpleasant, even though non-fatal health effects on the way to the worst case. THat doesn't mean they're acceptable. I think the cancer talk and small percentage talk (which is mostly about external exposure) is inappropriate.

Anonymous said...

"@anon at 9:17PM, the political class in Japan has pretty much spoken, hasn't it? that they do not want a future with healthy children. They don't seem to want any future at all as a nation. "

It is their endgame in which they intend to take it all with them.

It is their 'vengeance' is the impression I am left with.

Little Canary said...

If the retirement pensions have been swiped out from the Japanese national arks, is understandable that this crisis is a win win situation for the japanese political class.

Imagine, more youth sick unable to work and heavily dependent from the Big Pharma Corporations and older dying faster than normal due to radiation.

Could be this the future that politicians needs in order to clean up the mess they got involved in past years?

Anonymous said...

Yes, the Tondel et al study is a good starting point. His conclusion as you stated is : 'The conclusions seem plausible, although the effect, about an 11% increased risk at a 100kiloBequerel/meter squared deposition, is small. '

But I do not think that this is a small effect. Since Tondel et al gives the risk averaged over all age groups! We know from the Beir 7 report (table 12D-1 p311) that the young ones will be most affect. The people currently under the age of 20 years will have to bear 90% of this increase, but they do not represent 90% of the Japanese population.
This means, while the risk for the Mayor of Tokyo (now 78) is close to zero, the risk for a person under the age of 20 is 3-5x higher than the averaged increased risk you stated from the Tondel study. Thus a very conservative estimation would put the risk increase based on these two studies for a person under the age of 20 to about 33% at 100 kBq/m*m . For kids currently under the age of 10 years it is even worse and girls are twice as sensitive as boys towards radiation.

This is insane!

Anonymous said...

again anon 5:39AM

sorry, I made a calculation mistake, the people currently under the age of 20 will not have to bear 90% but only 67.7% of this risk increase.
By the way, people who are currently 60 or older only have to bear 7.5% of the increased risk to get cancer due to the radiation exposure during their lifetime.

It is still insane!

netudiant said...

Hi anonymous,
That the young will be more affected is plausible. I'm unfamiliar with the report you refer to, is there a reference?.
That said, do note that the deposition levels in Sweden that were involved in the 11% risk increase were 100,000Bq/Meter, rather higher than most of those in Japan, although there were also much worse contaminated spots.
Imho, it is appropriate to focus on the cancer risks from this disaster, because the amounts of material involved are at such low concentrations, in the parts per trillion range,
that biochemical effects seem impossible.

Anonymous said...


just follow this link:

you will have to provide your email address, but you can download for free. The Beir 7 report is issued by the 'Committee to Assess Health Risks from Exposure to Low Levels of Ionizing Radiation, National Research Council ' financed by the DOD, DOE and EPA (US Gov.)

Enjoy reading

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