Inadequate assessment of radioactive iodine in Fukushima food and water

After the nuclear accident, residents of Iitate Village had an earnest and urgent request that went unheard: “We would like to have measurements taken of the residents before iodine 131 becomes undetectable.” Then five months later, when
graph Iodine -131 half lifeno iodine would be detectable at all, it was announced that a whole body counter study will begin to measure the internal exposure dose of Fukushima residents. Now, however, dose assessment is said to be impossible due to “the lack of direct measurements in residents immediately after the accident.” Government experts should have been well aware of the half-life of iodine 131. Why did they not conduct a thorough survey at the time while iodine 131 was still detectable?
Ordinarily one would conduct an internal exposure survey as soon as possible. But the Oversight Committee Chairman Hoshi keeps putting it off, repeating, “This is a future task for us to discuss and decide.”
 
Oshidori Mako Interviews Experts Regarding Excess Occurrence of Pediatric Thyroid Cancer in Fukushima, Fukushima Voice, English Version 6 Aug 15,”…….
Issue to be considered #3: 
Was the contaminated food under control?
Were there sufficient post-accident exposure studies?
Both epidemiologists and clinicians state in unison, “Dose assessment is not our specialty, so all we can do is to accept the reported assessment.”
I interviewed a dose assessment expert and one of the members of the Oversight Committee for “Fukushima Health Management Survey,” Professor Shinji Tokonami of Hirosaki University.
Mako: “Professor Tokonami, as an expert, do you think the dose assessment after the Fukushima nuclear accident has been adequate?”
“I think it has been inadequate,” replied Professor Tokonami. “There have been hardly any measurements taken of residents’ exposure doses after the nuclear accident. The half-life of iodine 131, which damages thyroid gland, is 8 days, and it cannot be measured later. All you can do is retroactively estimate the dose from fragmented data of iodine remaining in soil and air.”
Mako: “Can we still conduct such retroactive estimation?”
Prof. Tokonami: “Iodine moves around in various ways in the environment. After the accident, the radioactive plume released from the nuclear reactors, including radioactive iodine, dispersed in every direction. I think the individual exposure dose will vary widely depending on where each person was at the time of the accident and whether the person was hit by the radioactive iodine plume.”
Mako: “Investigation by the Oversight Committee mostly had to do with estimation of external exposure dose based on the record of people’s behavior; it lacks the internal exposure dose assessment based on food intake. (During the 2nd Oversight Committee Meeting, Shunichi Yamashita, who was then chair of the Committee, said, “This Committee will mainly deal with external exposure, and internal exposure is only considered peripherally.”) The Basic Survey questionnaire by the Fukushima Health Management Survey asks people to write in a four-month record of their behavior from March 11, 2011 to July 11, 2011. In regards to internal exposure, there is only a section on the last page of the questionnaire to “declare any consumption of produce grown outside on bare soil or water from a private water-supply system,” and the declaration period is only for 20 days—from March 11 to the end of March. Isn’t it necessary to conduct more survey on the internal exposure dose?
Prof. Tokonami: “I heard of occasions where residents were drinking water from the stream. It is possible to estimate the dose from recorded data if we know which private water-supply system was used by making calculations based on the amount of daily water consumption.”
Mako: “Isn’t it necessary to conduct detailed dose assessment at least in children diagnosed “confirmed or suspicious of malignancy”?
Prof. Tokonami: “We can’t conduct any direct measurements now. What we could do is repeat dose reconstruction from answers on behavior questionnaire of the thyroid cancer patients as well as from some scattered data available.”
Contamination of food and contaminated drinking water at evacuation centers
I learned through my investigation that contaminated vegetables, especially leafy vegetables, were in distribution after the 2011 nuclear accident. The government explains, “No contaminated food was distributed. Everything was under control.” However, when I visited the labs and research institutes which actually analyzed commercially distributed foodstuff, they said, “Some vegetables were loaded with iodine,” showing me various measurement data. Of course, this doesn’t mean every foodstuff was contaminated. Suspension and restriction of shipments of contaminated foods was working to some extent. However, some contaminated foods would occasionally slip by into distribution. Some researchers called it, “a bomb vegetable.”
In reality, the provisional regulation values for food was established on March 17, 2011, in response to the nuclear accident. Then, on March 19, 1,510 Bq/kg of iodine 131 was detected in milk from Kawabata Town, Fukushima Prefecture, and the Ministry of Health, Welfare and Labour (MHWL) sent out a request to ban its sale. Also on March 19, 15,020 Bq/kg of iodine 131 was detected in spinach from Takahagi City, Ibaraki Prefecture, and 14,500 Bq/kg of iodine 131 in spinach in Hitachi City, Ibaraki Prefecture.
But the MHLW website simply states, “We were contacted by Ibaraki Prefecture regarding the press release shown below.” and there were no special measures actually taken by MHWL itself. Takahagi City and Hitachi City are in Ibaraki Prefecture where pediatric thyroid cancer cases have been detected other than Fukushima Prefecture. Is this simply coincidental?
On March 20, there were reports, from Tochigi, Chiba and Gunma Prefectures, of vegetables exceeding the provisional regulation values. Again, here, MHLW merely “requested voluntary suspension of shipment” from each of these prefectures, without actually taking any direct measures. It wasn’t until March 21 that MHWL finally issued an order for restricting shipments. Furthermore, it’s not as if the suspension of shipments and the radiation testing were being applied to every single food item. Unfortunately, university research labs or research institutes declined to publicize their own measurement data for this article. Apparently, releasing such proof that contaminated food was in distribution after the accident is difficult in the current atmosphere as it goes against the announcement by the government.
There is another circumstance of individuals not having information regarding what kind of food and drinking water they consumed. During my information gathering activities in Iitate Village, Fukushima Prefecture, in May 2011, someone who evacuated from Iitate Village told me the following story: “Immediately after the accident, about 2,000 Minamisoma residents evacuated to Iitate Village, running away from tsunami. But when they learned Iitate Village became contaminated with radioactive materials, they evacuated from Iitate Village. This means evacuation centers in Iitate Village existed only for 3 to 4 days. But several days later, on March 20, it was discovered that the private water-supply system in Iitate Village was extremely contaminated. It was the evacuees at the evacuation centers that were using the contaminated private water-supply system.”
An MHLW document released on March 21, 2011, states that, as of 12:30 pm March 20, the private water-supply system in Iitate Village had 956 Bq/L of iodine 131 and 153 Bq/L of iodine 132. The document stated that, as of 8:30 am March 21, there was 492 Bq/L of iodine 131 and 54.1 Bq/L of iodine 132.
According to this document, there is a significant amount of iodine 132 detected, with a half-life of 2-3 hours. By the following day, iodine 131, with a half-life of 8 days, is nearly halved. Why was something with a half-life of 8 days reduced to half the amount by in one day? Professor Tokonami says, “When it comes to tributaries, a private water-supply system receives intake from various streams, and dilution might be fast.” The half-life of iodine 131 is 8 days, and that of iodine 132 is 2-3 hours. Considering the fact iodine 131 was nearly halved from March 20 to March 21, calculating backwards to March 15 the iodine 131 concentration is estimated to be several tens of thousand Bq/L.
The man I interviewed in Iitate Village turns out to be a public worker who managed the evacuation centers at the time, and he was extremely regretful that he “inadvertently provided the evacuees with contaminated drinking water.” I interviewed five Minamisoma residents who evacuated to Iitate Village, and none of them was aware of the contamination in the private water-supply system they used during evacuation.
Un-investigated Iodine 131
Is it not necessary to conduct a detailed internal radiation exposure questionnaire survey while people’s memory is still fresh and while information can be traced? How can we complete dose assessment without even conducting surveys that can still be conducted?
Nuclear Safety Commission recommended an additional survey on March 30, 2011, citing inadequacy of thyroid monitoring on 1,080 children. However, the Special Headquarters for Measures to Assist the Lives of Disaster Victims turned down the recommendation stating, “An additional survey is not to be conducted as it may create a significant degree of anxiety for the survey subjects and their families, as well as the local communities.”
After the nuclear accident, residents of Iitate Village had an earnest and urgent request that went unheard: “We would like to have measurements taken of the residents before iodine 131 becomes undetectable.” Then five months later, when no iodine would be detectable at all, it was announced that a whole body counter study will begin to measure the internal exposure dose of Fukushima residents. Now, however, dose assessment is said to be impossible due to “the lack of direct measurements in residents immediately after the accident.” Government experts should have been well aware of the half-life of iodine 131. Why did they not conduct a thorough survey at the time while iodine 131 was still detectable?
In April 2011, an organization of young adults from Iitate Village called Magenedo Iitate (literally means Iitate won’t be beaten) pleaded to various organizations such as Tokyo Electric Power Company (TEPCO), Fukushima Prefectural Office, and MHWL to conduct measurements of the internal exposure dose of children: “We were told that priorities were given to Self-Defense Force soldiers, police officers and firefighters in regards to internal exposure measurements in parts of East Japan around Fukushima, with residents set aside for later time. We asked them to at least measure the internal exposure dose of the children, telling them we would pay our own way to get wherever the internal exposure testing is conducted, even Kyushu or Hokkaido.” At the end, their plea was never answered. Now, they can barely contain their outrage: “They can’t conduct the dose assessment due to lack of direct measurements of the residents in the immediate post-accident period? We begged to have direct measurements taken, for fear of lack of data impeding dose assessment. They waited until the iodine was gone before starting the whole body counter measurements.”
Internal exposure survey needed
It is not acceptable to disregard what can still be done, such as gathering scattered data (measurements of food, atmosphere, and soil) and redoing a detailed behavior questionnaire, in order to investigate which plume might have been encountered by residents or the contamination level of food that was being consumed by them. Internal exposure survey is included in the Basic Survey of Fukushima Health Management Survey, but it covers only 20 days’ worth of information up to March 31, 2011. Shouldn’t we at least conduct a more detailed investigation on the internal exposure of children diagnosed as “confirmed or suspicious of malignancy,” gathering such information as what they ate during 2011?……
This is the 5th post-accident year. If a study were to be conducted to investigate the internal exposure during 2011 of the children diagnosed as “confirmed or suspicious of malignancy,” we should not wait too long as the longer the wait the more the memory fades. Ordinarily one would conduct an internal exposure survey as soon as possible. But the Oversight Committee Chairman Hoshi keeps putting it off, repeating, “This is a future task for us to discuss and decide.” It has been four years since the Oversight Committee was launched. Chairman Hoshi has not given any concrete statements regarding specific time tables. All he does is keep repeating the same word, “This is a future task.”
Since the Fukushima nuclear power plant accident, Oshidori Mako & Ken have attended and covered Tokyo Electric’s regularly scheduled press conferences and almost all the committee meetings sponsored by the government or Fukushima Prefecture. They are active in conducting interviews of experts as well as on-site fact-gathering investigations. The number of the Tokyo Electric press conferences attended by Oshidori Mako and Ken is the highest of all the Japanese journalists. http://fukushimavoice-eng2.blogspot.jp/2015/08/oshidori-mako-interviews-experts.html
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