Monday, June 27, 2016

Cesium Nanoparticles from Fukushima Persist in Environment, May Pose Additional Risks


PhysOrg has a report on findings presented at a recent conference by Dr. Utsunomiya of Japan, who found persistent cesium nanoparticles. He observed that these nanoparticles may pose additional risks because of their durability. 

Prof. Bernd Grambow, Director of SUBATECH laboratory, Nantes, France and leader of the research group on interfacial reaction field chemistry of the ASRC/JAEA, Tokai, Japan, agreed with this conclusion and is quoted in the article as stating that the nanoparticles have implications for how inhalation doses for humans are assessed because the "biological half- lives of insoluble caesium particles might be much larger than that of soluble caesium...."

Here is a brief synopsis of the article:

Radioactive cesium fallout on Tokyo from Fukushima concentrated in glass microparticles

June 27, 2016


Read more at: http://phys.org/news/2016-06-radioactive-cesium-fallout-tokyo-fukushima.html#jCp


Analysis from several air filters collected in Tokyo on 15 March 2011 showed that 89% of the total radioactivity was present as a result of these caesium-rich microparticles, rather than the soluble Cs, as had originally been supposed. (June 27, 2016). PhysOrg, http://phys.org/news/2016-06-radioactive-cesium-fallout-tokyo-fukushima.html

According to Dr Satoshi Utsunomiya: "This work changes some of our assumptions about the Fukushima fallout. It looks like the clean-up procedure, which consisted of washing and removal of top soils, was the correct thing to do. However, the concentration of radioactive caesium in microparticles means that, at an extremely localised and focused level, the radioactive fallout may have been more (or less) concentrated than anticipated. This may mean that our ideas of the health implications should be modified"...

Radioactive cesium is still being regularly detected in Japan by citizen scientists who are sampling their communities and their food:

Masakazu Honda. May 6, 2016. 30 groups show radioactive soil levels to address Fukushima fears. The Asahi Shimbunbhttp://www.asahi.com/ajw/articles/AJ201605060006.html

A coalition of 30 private groups is digging deeper into radiation contamination from the 2011 Fukushima nuclear disaster to address persistent concerns from the public around Japan….

...The highest reading so far was 135,000 becquerels of radioactive cesium detected in a forest near a home in the Hiso district of Iitate village, northwest of the embattled Fukushima No. 1 nuclear power plant.

The soil sample showed 111,028 becquerels of cesium-137 and 23,920 becquerels of cesium-134.

Radioactivity readings at many observation spots in Shizuoka Prefecture, which is far from the nuclear plant, were below the lowest detectable level.

But the survey this year still found sites in the Kanto region, south of the Tohoku region where the Fukushima plant is located, with readings exceeding 10,000 becquerels.

Cesium bioaccumulates in organs, as demonstrated by monkeys in Japan who have retained radioactive cesium in muscle tissue:

Bahar Gholipour Fukushima monkeys show signs of radiation exposure Livescience.com July 24, 2014, http://www.cbsnews.com/news/fukushima-monkeys-blood-shows-signs-of-radiation-exposure/

The results showed Fukushima monkeys had lower counts of red and white blood cells, and other blood parts compared with 31 monkeys from Shimokita Penisula in northern Japan. The researchers also found radioactive cesium in the muscles of Fukushima monkeys, ranging from 78 to 1778 becquerels (units of radioactivity representing decay per second) per kilogram, but they didn't find any in Shimokita monkeys. [7 Craziest Ways Japan's Earthquake Affected Earth] Exposure to radioactive materials may have contributed to the blood changes seen in Fukushima monkeys, study researchers Shin-ichi Hayama and colleagues wrote in their study, published today in the journal Scientific Reports. Low blood cell counts could be a sign of a compromised immune system and could potentially make the monkeys vulnerable to infectious diseases, the researchers said.
Here is the relevant academic publication and an excerpt from the abstract, that describes cesium concentrations:
Kazuhiko Ochiai , Shin-ichi Hayama , Sachie Nakiri et al "Low blood cell counts in wild Japanese monkeys after the Fukushima Daiichi nuclear disaster,"Scientific Reports 4, Article number: 5793 (2014) doi:10.1038/srep05793, http://www.nature.com/articles/srep05793

[excerpted] Total muscle cesium concentration in Fukushima monkeys was in the range of 78–1778 Bq/kg, whereas the level of cesium was below the detection limit in all Shimokita monkeys. Compared with Shimokita monkeys, Fukushima monkeys had significantly low white and red blood cell counts, hemoglobin, and hematocrit, and the white blood cell count in immature monkeys showed a significant negative correlation with muscle cesium concentration. These results suggest that the exposure to some form of radioactive material contributed to hematological changes in Fukushima monkeys.
The study in Scientific Reports detected cesium levels ranging from 78-1778 Bq/kg in monkey muscle while the poop measured by nuclear engineer Arnie Gundersen's colleague measured 50,000 Bq/kg. (see Gundersen's interview here).

The Fukushima disaster has contaminated Japan with over 1,000 genotoxic radionuclides. Cesium-134 and Cesium-137 are simply among the easiest to measure. 

And the contamination processes are not over yet:






New research shows that most of the radioactive fallout which landed on downtown Tokyo a few days after the Fukushima accident was concentrated and deposited in non-soluble glass microparticles, as a type of 'glassy soot'. This meant that most of the radioactive material was not dissolved in rain and running water, and probably stayed in the environment until removed by direct washing or physical removal. The particles also concentrated the radioactive caesium (Cs), meaning that in some cases dose effects of the fallout are still unclear. These results are announced at the Goldschmidt geochemistry conference in Yokohama, Japan.

Read more at: http://phys.org/news/2016-06-radioactive-cesium-fallout-tokyo-fukushima.html#jCp
New research shows that most of the radioactive fallout which landed on downtown Tokyo a few days after the Fukushima accident was concentrated and deposited in non-soluble glass microparticles, as a type of 'glassy soot'. This meant that most of the radioactive material was not dissolved in rain and running water, and probably stayed in the environment until removed by direct washing or physical removal. The particles also concentrated the radioactive caesium (Cs), meaning that in some cases dose effects of the fallout are still unclear. These results are announced at the Goldschmidt geochemistry conference in Yokohama, Japan.

Read more at: http://phys.org/news/2016-06-radioactive-cesium-fallout-tokyo-fukushima.html#jCp
New research shows that most of the radioactive fallout which landed on downtown Tokyo a few days after the Fukushima accident was concentrated and deposited in non-soluble glass microparticles, as a type of 'glassy soot'. This meant that most of the radioactive material was not dissolved in rain and running water, and probably stayed in the environment until removed by direct washing or physical removal. The particles also concentrated the radioactive caesium (Cs), meaning that in some cases dose effects of the fallout are still unclear. These results are announced at the Goldschmidt geochemistry conference in Yokohama, Japan.

Read more at: http://phys.org/news/2016-06-radioactive-cesium-fallout-tokyo-fukushima.html#jCp

12 comments: