Finally Released Partial WSPEEDI Data
On May 10, the Ministry Education, Culture, Sports, Science and Technology (MEXT) released a part of the WSPEEDI (2nd generation SPEEDI) forecasting data which they had concealed until now. WSPEEDI can forecast radioactive contamination of as far as thousands kilometers; therefore, it could forecast the contamination spreading all over Japan. MEXT, however, only released data from some parts of Nagano and Shizuoka Prefectures in the South to some parts of Iwate and Akita Prefectures in the North. In addition, the data is limited on amounts of Iodine 131 of March 25, 2011. Though it is a forecasting data, it can give more detailed data on spreading contamination of radioactive materials than the other data that the Japan Meteorological Agency released in April. So I consider this WSPEEDI data as crucial in order for people to know what is going on, and I honestly cannot hide my shock that Tokyo Electric Power Company (TEPCO) finally released this data 2 months after the incident. I strongly believe that people who decided to hide the data until now have to be judged by the law in the near future because this data (of even only on March 25) is THAT important! Here's my analysis on the released WSPEEDI data.
Contamination Forecast of Accumulated Iodine 131 on the Land, March 25, 2011
click the image to expand
<Severely Contaminated Area – Yellow : 1,000,000 – 10,000,000 Bq/m2>
The area includes not only the eastern part of Fukushima Prefecture (already an evaluation zone) but also from the northern part of Koriyama City; the central part of Fukushima Prefecture; the southern part of Shiraishi City of Miyagi Prefecture, to Kitaibaraki City and Hitachi City of Ibaraki Prefecture (the south of Iwaki City). The page 2 of the MEXT document also contains shocking data of glandula thyreoidea equivalent dose of Iodine 131 for infants. According to the data, 50 to 100 mSV (millisievert) of extremely high dose of Iodine 131 (glandula thyreoidea equivalent dose) was found in the wide area including Motomiya City of Fukushima Prefecture and Takahagi City of Ibaraki Prefecture (in red); over 20 mSV of Iodine 131 was found in the area including Fukushima City of Fukushima Prefecture, parts of Miyagi, Ibaraki and Chiba Prefectures (in yellow).
<High Contaminated Area – Green: 100,000 – 1,000,000 Bq/m2>
The area includes most of the central Fukushima Prefecture; about 80% of Miyagi Prefecture; the southeastern Yamagata Prefecture; most of Ibaraki Prefecture; about a half of Tochigi Prefecture; the northern, eastern, and southern Chiba Prefecture; about 40% of Saitama Prefecture; about 20% of Gunma Prefecture; most of Tokyo except for Okutama; about 50% of Kanagawa Prefecture including a part of Yokohama City; Izu Peninsula of Shizuoka Prefecture (Atami City to Ito City), etc.
<Intermediate Contaminated Area – Light Blue: 10,000 – 100,000 Bq/m2>
The area includes most of the other parts of the Tohoku region (northeast Japan), Kanto region (where Tokyo is), Shizuoka Prefecture and Yamanashi Prefecture. The Tohoku region of this area includes the southeastern part of Akita Prefecture, about 50% of Niigata Prefecture (especially the south); the northeastern part of Nagano Prefecture.
<Low Contaminated Area – Dark Blue: 1,000 – 10,000 Bq/m2>
The area includes Tokai Region and a part of Hokuriku and Tohoku regions that face the Japan Sea.
*Super High, High, Intermediate, and Low Contaminated Areas are named by this blog for the purpose of explaining the contamination levels on the WSPEEDI data that was released. Also, for your information, Iodine 131 becomes Xenon 131 after emitting all the radiation.
Estimation of Accumulated Cesium 137 on the Land
Our past article showed data of accumulatedamounts of Iodine 131 and Cesium 137 by simply summing the values that have been announced daily by the MEXT (though the data is only available after March 19 and most of the data of Miyagi and Fukushima are not available). When looking at the proportions of Iodine 131 to Cesium 137, 3.3 times more Iodine 131 in Shizuoka, 8.1 times more Iodine 131 in Ibaraki, 13.2 times more Iodine 131 in Tokyo, and 40 times more Iodine 131 in Chiba, are accordingly found when compared Cesium 137. I apply these proportions to the WSPEEDI data and predict the accumulated amounts of Cesium 137 below.
<Estimation of Cesium 137>
Chiba City of Chiba Prefecture : 250 – 2,500 Bq/m2
Tokyo (except for Okutama): 7,700 – 77,000 Bq/m2
A part of Shizuoka Prefecture (including Atami and Ito): 30,000 – 300,000 Bq/m2
Ibaraki (except for Kitaibaraki and Hitachi): 12,500 – 125,000 Bq/m2
Central Fukushima City : 50,000 – 500,000 Bq/m2
Please note that another agency called the Japan Chemical Analysis Center in Chiba City released very different findings. The center detected 48,000 Bq/m2 of Iodine 131, 53,000 Bq/m2 of Cesium 134, and 53,000 Bq/m2 of Cesium 137 on the surface of graveled soil on April 14, 2011 (The data include results from March 26 to April 14, but when you look at amounts of each material, it is certain that high contamination occurred before March 25). Also, because we know that most of the Tokyo area is contaminated higher than that of Chiba City, Cesium 137's amount in Tokyo probably cannot go below Chiba City's amount of 53,000 Bq/m2 (The MEXT data also shows more Cesium 137 detection in Tokyo than in Chiba City). As for the central part of Fukushima Prefecture, the MEXT's airmonitoring data that was released on May 6 similarly shows accumulated amount of at least 300,000 Bq/m2 Cesium 137. In sum, my estimation of Cesium 137 above is more realistic when you look at the maximum numbers than the minimum numbers.
Applying to the Chernobyl's Contamination Zones
Here I apply the numbers to the Chernobyl'scontamination zones. I use the maximum numbers of estimation and the reason of that has been mentioned in the above paragraph.
<Cesium 137>
Tokyo (except for Okutama): 77,000 Bq/m2 (MBq/km2) = 2.1 Ci/km2
Ibaraki (except for Kitaibaraki and Hitachi): 125,000 Bq/m2 (MBq/km2) = 3.4 Ci/km2
Central Fukushima City: 500,000 Bq/m2 (MBq/km2) = 13.5 Ci/km2
* Ci = 37,000 MBq (MBq = 1,000,000 Bq)
Central Fukushima's 13.5 Ci/km2 equals to the Second Contamination Zone of Chernobyl (5-15 Ci/km2). Tokyo's 2.1 Ci/km2 equals to the Third Contamination Zone of Chernobyl (1-5 Ci/km2). I have already stated that Chiba City is already contaminated to the level of the Third Contamination Zone of Chernobyl, but from the WSPEEDI data, most of the Tokyo area possibly equals to the Third Contamination Zone. At the Third Contamination Zone of Chernobyl, dramatic increases of cancers and leukemia started among residents 10 to 20 years after the incident mainly due to internal exposures to radioactive materials by the air and local food supplies.
These numbers used in this calculation are of course estimated ones (because the government and TEPCO still conceal vital information!!), but please don't forget that these estimated numbers are as of March 25 and a lot more Cesium and other materials have been emitted since then and still continue now. I can assume that it can be less contamination on concreted land as materials can be washed away easily compared to sanded land. But, still, the contamination level overall is a lot more than what we thought it was. It is very possible that area near Fukushima City could have reached the First Contamination Zone that former Soviet Union forced its residents to leave their homes. According to the airmonitoring data by the MEXT, at Iidate Village that is located outside of the 30km evacuation zone, more than 81 Ci/km2 of Cesium 137 were detected (and people still live there now!).
I continue to ask the government to release ALL the data that they have, whether it is actual detection or forecasting data, as well as to start measuring Plutonium and Uranium (if they really have not done so). Moreover, I urge the government to revisit the inhumane safety standards of 20 mSv for school children and food/water consumptions that is set so much looser than international standards. Finally, please come up with ideas and plans to eliminate/clean up radioactive materials that have been so spread all over the country (or I should say all over the World).
Postscript
A reader of our blog, Mr. Tengu, has provided us this very interesting information. Mr. Tengu captured this image on NHK (Japanese national broadcasting program) in mid-April. He was watching a NHK program called "Asaichi (Morning First)". While the government had refused to disclose the SPEEDI data from the beginning of the crisis, this information proves that the SPEEDI data on March 16 (written on the screen image) existed at the hands of government officials. The second image below is created by Mr. Tengu who expanded the SPEEDI data and put it together with a more detailed map of the area.
Despite the fact that the image on the TV program says it's the SPEEDI data, this looks like the WSPEEDI on Iodine-131 Infant Organ Dose from March 15. This came out in mid-April, which means that NHK had the data before Kosako revealed in the end of April that the government had concealed the SPEEDI data. This proves that the government possessed such data at least from March 15 (though I bet that they have the WSPEEDI data from March 11). As the map above shows, serious amounts of radioactive materials spread over the Kanto region especially in Saitama and Gunma prefectures. The government has so much responsibility for not disclosing these data on time, which could have prevented unnecessary exposures to radiation if appropriate warnings had been delivered to the public.
