Radioactive Strontium Detected in Yokohama - High Radiation Levels Detected in Tokyo

[kristopher]

Radioactive Strontium Detected in Yokohama
High Radiation Levels Detected in Tokyo's Setagaya Ward
Thursday, October 13, 2011

Tokyo- (PanOrient News) Radioactive strontium exceeding normal quantities has been detected in sediment from atop an apartment building in Yokohama, , south of Tokyo, and radiation levels as high as 2.707 microsieverts per hour have been detected on a local sidewalk in Tokyo's Setagaya Ward, Japanese media reported.

The strontium 90 was detected in Yokohama, some 250 kilometers from the damaged Fukushima Daiichi nuclear power plant, by a private agency that conducted the test upon the request of a resident. This is the first time strontium at a concentration of over 100 becquerels per kilogram has been found beyond 100 km from the Fukushima plant.

While the discovery of 195 becquerels of strontium 90 in the rooftop sediment has fueled concerns that leaked radiation may have spread further than the government had expected, the officials said the city office is carefully examining where the material came from, Kyodo reported.

Strontium 90 has been detected at concentrations roughly between 10 to 20 becquerels at various places across Japan prior to the nuclear crisis triggered by the March 11 earthquake and tsunami.

The Yokohama city ...

http://www.panorientnews.com/en/news.php?k=1290

Setagaya ward is in the heart of Tokyo.

[valerief]

1. Who could have seen that coming?

:eyes:

[Journeyman]

3. Certainly not anyone who's paycheck depended on not seeing it . . .

[valerief]

8. You got that right. nt

[FBaggins]

2. That's a period... not a comma, right?

Your sources seem to continually redefine the definition of the word "high".

[Blues Heron]

4. what about the strontium?

How dangerous is 195 becquerels/kg (if at all)? thanks.

[FBaggins]

5. Not particularly noteworthy

That's just slightly above the radioactivity of the human body (about 120 Bq/kg).

You'll no doubt see "BONE SEEKER!!!!" eventually (and it is), but consider where this is. They keep finding the highest levels in substances that concentrate the element hundreds/thousands of times over (or more). Incinerator ash, drains, air filters, etc. - it isn't indicative of overall environmental exposure. Is some kid with pica going to go up there and eat a pound of the stuff?

They'll also breathlessly start citing this as if it's now the level that people in Tokyo are exposed to on an ongoing basis... but unless you spend your life in the gutter (not something I would put past a few), that simply isn't true.

The article also notes that strontium contamination existed at 5-10% of that level pre-Fukushima. Such contamination would be far from homogeneous. It isn't unreasonable to question whether ANY of the detected strontium can be attributed to Fukushima. It probably can, but the amounts are so low (as with prior detections of Plutonium) to make it less than certain.

[kristopher]

6. I'm sure nuclear industry propaganda will be a great comfort

...to those who actually have to live there and raise their children with the risks.

[FBaggins]

7. Feel free to cite an actual health physicist who says anything else.

A straight reporting of the facts is frequently inconvenient for your positions... but that doesn't make it "propaganda".

[Yo_Mama]

16. It's not what you hope to see

But it's puzzling given the strontium numbers I have seen from Fukushima, where surely there should have been more. The highest I remember from the Fukushima area was 250 becquerels/kg. The highest number I remember from the soil at the Fukushima Daiichi plant itself was 480 becquerels/kg:
http://www3.nhk.or.jp/daily/english/01_h01.html

I think the highest contamination for strontium 90 during the nuclear testing era for Japan was around 50 becquerels per kg.

I have to wonder how a number that high could be on a roof in Tokyo! There was only one brief period early on in the disaster when the wind blew south toward Tokyo; unless almost all of the Strontium 90 emissions occurred early on during that period there should be no way the roof could be that contaminated.

In terms of danger to humans:
Strontium 90 isn't that bioavailable. 20 - 30% of it is retained. Strontium 90 contamination is pretty widespread globally. On the rooftop it is not much of a danger. You wouldn't want to see it in water. In agricultural soils it can be a problem due to uptake and subsequent ingestion by humans.

Yokohama is going back and testing their ditch samples for strontium 90 now - they'll know more in a bit:
http://www.nippon-sekai.com/main/articles/fukushima-daiichi-nuclear-power-plant-crisis/yokohama-city-tests-soil-for-strontium/

Note the extremely high contamination levels from cesium already detected! (40K becquerels/kg.) That's the real threat, although it doesn't translate well into human exposures, because you expect cesium to concentrate in drainage areas.

If I had to guess, I would say that the rooftop reading is either an error or stems from contaminated building components, probably steel. If that were true, it would be no threat to humans at all.

So far, the strontium-90 concentrations reported in Japan seem unlikely to affect human health. They are similar to a lot of US exposures during the nuke-ourselves era (I am a proud graduate), and because of the filtering effect, lifetime exposures are probably going to be less than say, mine. Anyway, if you want background info, try these links:
http://www.epa.gov/superfund/health/contaminants/radiation/pdfs/strontium.pdf
(General)

http://www.epa.gov/radiation/rert/nuclearblast.html
(specific, with some graphs)

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1915172/pdf/pubhealthreporig00096-0053.pdf
(analysis of milk exposure in human diet - US)

http://www.epa.gov/rpdweb00/docs/federal/frc_rpt4.pdf
(very detailed analysis of dietary exposures extrapolated to lifetime risk for human population during blast era)\

Short summary if you don't want to read all that:
http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/tooth-fairy.html

By far, the largest source of Sr-90 in the environment (~99%) is from weapons testing fallout. Approximately 16.8 million curies of strontium-90 were produced and globally dispersed in atmospheric nuclear weapons testing until 1980 (UNSCEAR 2001)2. With a 28 year half-life, Sr-90 still remains in the environment at nominal levels. Numerous measurements were made during weapons testing which found that the worldwide average radiation dose from ingesting Sr-90 (1945 to present) is 9.7 millirem (about equal to radiation doses from a transpolar flight), and the dose from inhaling strontium-90 (1945 to 1985) is 0.92 millirem (about equal to the dose from an arm or leg x-ray). These doses are well below those doses known to cause any effects on health (NCRP 1991)3. The doses from Sr-90 in the environment are about 0.3% of the average annual dose a person in the United States receives from natural background radiation (~300 millirem).

As a result of the Chernobyl accident, approximately 216,000 curies of Sr-90 were released into the atmosphere. An increase in the incidence of childhood thyroid cancer in the area directly affected by the accident has been attributable to radioiodine ingestion. No other increase in overall cancer incidence or mortality has been observed that can be attributed to radiation from the accident (UNSCEAR 2000)4.

There's a lot of nonsense written about low-dose radiation, including ridiculous death estimates. Strontium 90 exposures outside of the non-local area of the Fukushima Daiichi plant, based on everything we know and the unfortunate experiments conducted upon human subjects such as yours truly, are unlikely to cause detectable human health problems. The LNT model is obviously false - here's a pro/con argument pdf:
http://www.columbia.edu/~djb3/papers/rpd1.pdf

The con guy - Raabe - is an authority on studies in animals. See the graph on page 5, and note the dosage in Grays. Those are massive doses compared to anything we can reasonably expect the Japanese population to intake. The fact that no correlation seems to show for myeloma/bone cancers in the US for my age group implies that beagles and humans have a pretty high threshold for exposure without injury.

[kristopher]

17. "There's a lot of nonsense written about low-dose radiation"

Says the die easy nuclear fan...

[Yo_Mama]

18. WTF do you know about me?

FWIW, I did commercial work about a decade ago showing that what happened at Fukushima Daiichi would happen in the US if there were a real meltdown on a reactor. Nobody believed me when I predicted losses states away. The work was junked. I must admit that I never expected it to happen, and I am deeply grieved by such a vindication.

I'm hardly a die-hard nuclear fan. I want a lot of the older reactors closed down.

HOWEVER, I believe in truth. I really believe in it. The reason why I so often come up with piles of references like the above is because I already did the effing risk studies! And I already told you that those hotspots would appear. Look at that link on the Yokohama ditch and the cesium levels on the ditch.

For what it's also worth, the risks on most US reactors are quite low. Still a low risk on a reactor in a bad place (like too close to NY) is a net pretty high risk because it can't be mitigated.

The real discriminant pro/con nuclear power is how much weight you place on the CO2/warming hypothesis. Since I can find no confirmation that water vapor positive feedback loop exists, and since nothing that the west does will change CO2 accumulations meaningfully, I am relatively anti-nuclear power. I do accept that if the CO2 water vapor positive feedback loop exists that the risk matrix changes, but it still cannot justify keeping Hamaoka NPS open, for example.

Keeping the electricity grid up and running is very important to safeguard human life, but that doesn't necessarily translate to doing it with nuclear power. Just because I am not willing to pretend that the wind turbine fairies are going to come and remove the problem doesn't mean that I am a shill for the nuclear power industry.

[kristopher]

19. Just what you reveal in your regular postings to defend the nuclear industry.

If you are such a believer in truth (and I accept 100% that you think you are), then where are your posts challenging the routine falsehoods promoting nuclear power? Somehow, as evidenced by your ridicule of the No Linear Threshold Hypothesis, the only "truth" you seem motivated to share are ones that are endorsed by the nuclear industry establishment.

And then we have your snarky rejection of the massive body of evidence supporting the FACT that renewable energy is the most effective, direct and least costly route to a global sustainable energy system. There are only 2 groups that reject that body of work, one oriented around the fossil fuel industry and the other around the nuclear industry. There is ZERO scientific basic for their position.

[FBaggins]

9. Setagaya hotspot unrelated to Fukushima

See my #5 - "It isn't unreasonable to question whether ANY of the detected strontium can be attributed to Fukushima."

High levels of radioactivity observed in Tokyo's Setagaya Ward have been found to have nothing to do with the nuclear disaster in Fukushima. Experts commissioned by the ward reported a level of 3.35 microsieverts per hour at a 1-by-10-meter area at a sidewalk near a residential fence on Thursday. A maximum of 2.707 microsieverts per hour had been detected in the location a week before.

Later on Thursday, the experts found what seemed to be the source of the radiation -- 3 or 4 old jars in a wooden box left in a storage space under the floor of a vacant house facing the sidewalk. The jars were reportedly dirty and black, and measured about 8 centimeters long and about 6 centimeters wide. The radiation level of the bottles reportedly exceeded 30 microsieverts per hour -- higher than the maximum that could be measured with the experts' devices.

http://www3.nhk.or.jp/daily/english/13_41.html

"kris - slowly learning the difference between propaganda and facts... the hard way" :)

[miyazaki]

10. rotflmao. n/t

[kristopher]

11. The strontium is in Yokohama - on the other side of Tokyo from Fukushima

Your "prediction" was in reference to that, not to Tokyo. Which makes sense since you know that on the far western edge of Tokyo they have high readings; in Chiba on the eastern border of Tokyo they have high readings; and now to the south in Yokohama they have high readings.

You must be feeling pretty desperate for some sort of win to be claiming that you were somehow correct.

[FBaggins]

12. Lol!

Nice try.

Think anyone bought it?

The point is that the "high" levels weren't high enough to even tell that they came from the reactor failures.

You can claim "high" readings east, west, and south of Tokyo, but in reality there haven't been any readings that could rationally be considered "high" in an absolute sense. Only low readings that are higher than background.

I didn't have any idea where Setagaya was or that the OP references two different sources. I took it as a single story and saw your "Setagaya ward is in the heart of Tokyo" comment at the bottom.

[kristopher]

13. Lol!

Nice try.

Think anyone bought it?

[SpoonFed]

14. About as disconnected from reality as you can get...

okyo- (PanOrient News) Radioactive strontium exceeding normal quantities has been detected in sediment from atop an apartment building in Yokohama, ,

Did you miss the part about the Strontium-90 sediment on the rooftop and try to misdirect to suggest more "nothing-to-see-here" with regards to the sidewalk? Hmm. Fail.

[kristopher]

15. Strontium also found in Yokohama gutter

Radioactive strontium found in Yokohama gutter
BY YOSHIKAZU SATO STAFF WRITER
2011/10/16

YOKOHAMA -- Radioactive strontium has been found in a street gutter in Yokohama, appearing to confirm that the radioactive isotope has spread far beyond districts close to the Fukushima No. 1 nuclear power plant.

Sediment in the gutter in the Okurayama district of Kohoku Ward contained 129 becquerels of radioactive strontium-89 and strontium-90 combined per kilogram, city officials announced on Oct. 14. The results follow an earlier report that deposits of strontium had been found on a nearby apartment building's rooftop.

...Radioactive cesium of 39,012 becquerels per/kg was also detected in the sample from the gutter but it is the presence of strontium that makes the Yokohama reports exceptional. There had previously been no reports of strontium contamination beyond 100 kilometers of the Fukushima plant.

Although Kohoku Ward is about 250 kilometers from the Fukushima plant, the concentration found in the gutter is higher than the 77 becquerels per kilogram detected in soil in Fukushima city between April and May...

http://www.asahi.com/english/TKY201110150314.html