Friday, March 23, 2012

1.4 Million Bq/Kg of Radioactive Cesium in Swallow's Nest in Okuma-Machi, Fukushima

The Ministry of the Environment, whose mandate also includes protection of animals, says "There is no effect on humans" if one stays away far enough.

What about the birds, having grown up in a nest with 1.4 million becquerels/kg of radioactive cesium with 2.6 microsieverts/hour surface radiation?

From Kyodo News (3/23/2012):

ツバメの巣140万ベクレル 離れれば「影響なし」

1.4 million becquerels of radioactive cesium from a swallow's nest, "No effect" if you stay away

 環境省は23日、東京電力福島第1原発から約3キロ離れた福島県大熊町にある建物の壁で採取したツバメの巣から、1キログラム当たり約140万ベクレルの放射性セシウム(セシウム134と137の合計)を検出したと発表した。

The Ministry of the Environment announced on March 23 that 1.4 million becquerels/kg of radioactive cesium (Cs-134 and Cs-137) was detected from a swallow's nest taken from the wall of a building in Okuma-machi in Fukushima Prefecture, about 3 kilometer from Fukushima I Nuclear Power Plant.

 環境省によると、巣はセシウム濃度が高い付近の田んぼの泥や枯れ草を集めて作ったとみられる。千葉市の放射線医学総合研究所に運び、巣表面の放射線量を測定すると毎時2・6マイクロシーベルトだったが、約50センチ離れると同0・08マイクロシーベルトに下がったことから、同省は「近づかなければ巣による人への影響は無視できると考えられる」としている。

According to the Ministry, the nest was built from the mud from a nearby rice paddy and dead leaves with high radioactive cesium density. The nest was taken to the National Institute of Radiological Sciences (in Chiba City, Chiba), where the radiation levels were measured. It was 2.6 microsieverts/hour on the surface of the nest, but the radiation level dropped off to 0.08 microsievert/hour at 50 centimeters from the nest. The Ministry says that "if one stays away from the nest, it can be safely concluded that any health effect on humans can be ignored".

I can't find any press release on the subject at the Ministry of the Environment website, which is a disorganized mess (probably on purpose).

The Yamashina Institute for Ornithology announced last year that it would collect swallows' nests from various locations in Japan to test for radioactive materials. I wonder if they had done it. I would trust the institute much more than the Ministry of the Environment. Looking at their website, they are still collecting the nests from 2011.

8 comments:

Anonymous said...

Well it is no surprise if you move away form a point source (the nest is pretty small) the radiation levels will drop dramatically. So you go from 2.8 uSv/h at ~1 cm to 0.08 uSv/h at 50 cm from the nest in the LABORATORY.

I wonder if you would move away 50cm from the nest at the location where it was collected, what would your Geiger counter show? Definitely not 0.08 uSv/h.

My point is, you do not only need to stay away from the nest, you actually need to stay away from the area where the nest has been collected!

But with the current government, I would not be surprised if they soon allow growing rice in that rice paddy where the swallow collected the mud from. Maybe they will advice you to just stay a little bit away from the rice and one can safely conclude that there might be no health effects.....

Atomfritz said...

"The Ministry says that "if one stays away from the nest, it can be safely concluded that any health effect on humans can be ignored"."

They seem not to care at all for the poor animals who have to absorb many millisievert from breeding to fly-out.

The surviving chicks then will spread their genetic damage, "... can be ignored."

Sueecampbell said...

Keep smiling and don't go close to a tree or a leaf or a nest or grass and you'll be fine....you will....sure you will!
Shared thanks

Anonymous said...

soon, the japanese government wont be a government as it will have nobody to govern.

Anonymous said...

Actually, there you have it: radiation of any kind or strength is completely harmless. All you have to do is stay away from it. Gee, I wish someone had told us all sooner!

William Milberry said...

Small animals are more sensitive to radiation than humans because we are bigger and have a lot more skin, fat, and fascia which can protect more sensitive internal organs by absorbing/blocking some of the beta radiation. Small animals internal organs get a higher dose from external exposure.

I suspect however that the measurement made was probably gamma-only as the Japanese government and "researchers" have a knack for ignoring the whole picture.

The Japanese are reputed as having "a respect for nature." I live in a modest size town in a rural area of Japan and if I look around there are no old trees, there is no wildlife in the town, and if I go up to the mountain and look down all of the land looks like it was stripped bare. It's a stark contrast to my hometown in Pennsylvania which had big beautiful tress throughout the town, and small animals occasionally running across the street ... Based on little more than what I see around me, I see no "respect for nature" here in the slightest ...

arevamirpal::laprimavera said...

@William, I agree. Japanese think they have respect for nature. Or they want to believe they do. Or they believe in the propaganda that they do. But almost all rivers in Japan have concrete embankments, paved roads everywhere. Cities and towns are lit up at night with ghastly street lights.

If they respect nature, I don't think they will be boring a tunnel under the massive mountain range in the middle of Japan through the biggest fault line to have the maglev bullet train.

farfromhome said...

There is a reason my husband likes to call Japan the land of nature and...poured concrete.

Can't have 'nature' with out concrete in Japan.

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