Comparison study of calculated beta- and gamma-ray doses after the Fukushima accident in Minamisoma: skin dose estimated to be 164 mSv over 3 years

Comparison of calculated beta- and gamma-ray doses after the Fukushima accident with data from single-grain luminescence retrospective dosimetry of quartz inclusions in a brick sample

Journal of Radiation Research, https://doi.org/10.1093/jrr/rrx099
Published: 27 January 2018

ABSTRACT

To estimate the beta- and gamma-ray doses in a brick sample taken from Odaka, Minami-Soma City, Fukushima Prefecture, Japan, a Monte Carlo calculation was performed with Particle and Heavy Ion Transport code System (PHITS) code. The calculated results were compared with data obtained by single-grain retrospective luminescence dosimetry of quartz inclusions in the brick sample. The calculated result agreed well with the measured data. The dose increase measured at the brick surface was explained by the beta-ray contribution, and the slight slope in the dose profile deeper in the brick was due to the gamma-ray contribution. The skin dose was estimated from the calculated result as 164 mGy over 3 years at the sampling site.

INTRODUCTION

The main fission products from the Fukushima Daiichi nuclear power plant (FDNPP) accident are 129mTe-129Te, 131I, 132Te-132I, 134Cs, 136Cs and 137Cs [14]. These radionuclides emit gamma rays and beta rays through β decay. However, there are few studies about dose estimation from beta-ray irradiation following the FDNPP accident [57]. The beta-ray dose contributes to the whole-body dose among small biota, such as insects, plant leaves, and human skin. Therefore, beta-ray dose estimations are important for the risk assessment of the impact of the FDNPP accident (including on small biota) to clarify the effects of this large-scale radiological accident.

Retrospective dosimetry with brick samples has been used to evaluate the gamma-ray dose of the Hiroshima atomic bomb [810], the Chernobyl nuclear power plant accident [1114], and the Semipalatinsk nuclear weapon testing [15, 16]. Recently, Stepanenko et al. [17] used retrospective dose evaluation of brick samples to estimate gamma-ray doses and perform beta-ray dose reconstruction for the FDNPP accident with a similar method to that used for a Hiroshima tile sample [18]. They used a single-grain quartz optically stimulated luminescence (OSL) method (similar to that of Ballarini et al. [19], although layer-by-layer consequences for very thin layers of the sample’s aliquots were used for analysis, with separate dose calibration for each quartz grain) with brick samples taken in 2014 from Odaka, Minami-Soma City, Fukushima Prefecture, Japan [17]. Dose enhancement near the surface of the brick was identified by the OSL measurements [17]. Stepanenko et al. suggested that the enhancement was caused by the beta-ray dose from the deposited fission products [17].

To establish the cause of the dose enhancement near the brick surface, we performed a Monte Carlo simulation of a small brick building with radionuclides uniformly distributed on the ground surface. The calculated results were compared with the data measured by Stepanenko et al. [17]. The depth profiles of the dose in the brick sample for beta rays and gamma rays were estimated separately, and the dose enhancement near the brick surface was discussed.

MATERIALS AND METHODS

Particle and Heavy Ion Transport code System calculation

The energy deposition as a function of depth in the brick wall of a small building was calculated using the Particle and Heavy Ion Transport code System (PHITS) Monte Carlo code Ver. 2.52 [20]. The calculation geometries are shown in Fig. 1. The calculation regions were 1 m × 1 m for beta rays and 21 m × 21 m for gamma rays. The calculation regions consisted of ground, air, and the small brick building (red region: 0.5 m × 0.5 m square, 1.5 m high, wall thickness of 10 cm). The brick building was located in the center of the soil surface. Beta- or gamma-ray sources were uniformly distributed in the 5-mm-thick soil surface (brown region). To save calculation time, the previously reported mirror condition was used for these calculations [21]. Figure 1a shows the geometry used to calculate the radiation that entered the calculation region (outer source calculation) via the mirror boundary. First, the histories for the particles were accumulated near the mirror boundary (green lines) without the brick building. Second, the particles were generated from the mirror boundary (back line) in Fig. 1b according to the accumulated histories. The generated particles were transported to the brick wall cells (yellow box) of the brick building. Third, radiation was generated from the surface of the 5-mm-thick soil layer (brown region) in the calculation region (inner source calculation) in Fig. 1b. The energy deposition in brick cell layers of 10 m × 10 cm and thicknesses of 0.1, 0.2, 0.3, 0.4, 0.5, 1, 3, 5, 7.5, 10, 20, 40, 60, 80 and 100 mm were obtained by summing the outer and inner source calculations corrected with the number of particles generated per unit area.

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(a) Mirror condition calculation, (b) top view and (c) side view of the calculation geometry.

 

Beta and gamma rays from 129mTe, 129Te, 131I, 132Te, 132I, 134Cs and 137Cs were calculated separately. Beta-ray energy spectra were taken from the literature [5], and the internal conversion electrons of 137Cs were taken from the website of the National Nuclear Data Center [21]. The gamma-ray energies and emission rates for the radionuclides were taken from the National Nuclear Data Center [22].

The elemental composition of the brick sample was Si: 28.9, Si: 50.4, Al: 17.5, Fe: 1.4 and Ti: 1.8 wt %, and those of soil and air were taken from the literature [8].

Air dose and tissue dose calculation

The air and tissue dose rates at the i-th depth per unit deposition density of 1 Bq/m2, Dijk (Gy Bq−1 s−1 m2), for beta and gamma rays, were calculated from the calculated results of the energy deposition in brick as:

Dijk=Ijfcajc0EijkmbdE(j=β,γ;k=129mTe,129Te,131I,132Te,132I,134Cs,137Cs),
(1)

where Eijk is the energy deposition (J) at the i-th depth by beta or gamma rays from the k-th radionuclide, mb is the brick sample mass (kg), and aj is the area of the source (0.75 and 1 m2 for inner and outer beta calculations, 440.75 and 441 m2 for the inner and outer gamma calculations, respectively). Ij is the emission rate for beta or gamma rays per Bq and fc is the conversion factor of the stopping power ratio [23] for beta rays and the kerma ratio [24] for gamma rays between air or tissue and brick to convert from the brick dose to the air or tissue doses.

Cumulative dose estimation

The dose rate at the sampling point can be calculated by the measured deposition density, Ak, for each radionuclide at the sampling point of Odaka, Minami-Some City by multiplying the calculated result by Eq. 1. The change in dose rate over time is assumed to depend only on the half-lives of the radionuclides. Therefore, the cumulative dose, Ditot, for the i-th depth can be integrated by:

Ditot=kjτ0AkDijk(12)tTkdt,
(2)

where Tk is the half-life for each radionuclide of k = 129mTe, 129Te, 131I, 132Te, 132I, 134Cs and 137Cs (Table 1), and τ is the time period from deposition to the brick sampling date.

Capture du 2018-01-27 19-32-40

 

RESULTS AND DISCUSSION

Calculated dose rate for beta and gamma rays

A 137Cs deposition density of 308 kBq/m2 and the ratio of each radionuclide to 137Cs deposition density taken from the literature [1] were used to obtain Ak for each radionuclide. The deposition densities for the seven radionuclides are listed in Table 2. The beta-ray dose rates on the brick surface and gamma-ray dose rate at a depth of 0.5 mm in the brick at a height of 80 cm are shown in Fig. 2a and b, respectively. 129m, 129Te contributed less to the gamma-ray dose rate, and accounted for the third and fourth largest contribution to the beta-ray dose rate. This is due to the small gamma-ray emission rate per decay of 129m, 129Te of <10%. The gamma- and beta-ray doses decreased by ~10% and ~30%, respectively, over 1 month. The calculated beta-ray dose rate decreased slower than the calculated gamma-ray dose rate.

Capture du 2018-01-27 19-34-49

Capture du 2018-01-27 19-36-45.png

Capture du 2018-01-27 19-39-01.png

Air dose rates of (a) beta rays and (b) gamma rays over time.

 

Beck reported conversion factors for various radionuclides to estimate the air dose rate at a height of 1 m from the unit deposition density of radionuclides [25]. The initial gamma-ray air dose rates (15 March 2011) at a height of 80 cm from the ground for each radionuclide obtained by our calculations were compared with the values estimated by Beck conversion factors [25] interpolated at a relaxation depth of 0.65 g/cm2 (Table 2). The present dose rates were estimated to be 57% lower than those calculated by Beck conversion factors. The present dose rates were in-brick values in one of the walls of the brick building, whereas the Beck conversion factor values were free-in-air values. Therefore, the difference of 57% can be explained by shielding effects, whereby gamma rays from behind the building are neglected.

Cumulative dose

The cumulative dose over 3 years, from 12 March 2011 (Unit 1 explosion) to 19 March 2014 (brick sampling by Stepanenko et al.) and the dose rate change over time are shown in Fig. 3. The solid line shows the calculation result, the dashed histograms are the averaged calculation values for the measured sample thickness, and the open circles are Stepanenko’s data [17]. The calculation agreed well with the data measured by Stepanenko et al. in the region deeper than 10 mm. The results indicated that the cumulative dose deeper in the brick was due to gamma rays, and that the dose enhancement at the surface was dominated by the beta-ray contribution. The difference between the calculated and measured doses at the surface was about 2 standard deviations. A possible explanation might be connected with the contributions of low γ emission rate radionuclides, such as 89Sr, 127mTe-127Te, 140Ba-140La, etc. However, the trend in the dose increase at the brick surface was supported by the calculations. Therefore, the single-grain OSL measurement by Stepanenko et al. shows the advantage of dose estimations not only the cumulative gamma-ray dose but also the cumulative beta-ray dose. Thus, we concluded that the single-grain OSL method is a good tool for retrospective beta-ray dose estimation.

Capture du 2018-01-27 19-42-01.png

Comparison of the calculated beta rays (chain line), gamma rays (dotted line), beta + gamma rays (solid line), dose averaged over sample depth (dashed histogram), and data measured by Stepanenko et al. (open circles).

 

The calculated tissue dose at a brick depth of 50 μm was assumed to be a skin dose, and would be similar to a 70-μm tissue dose. The skin dose was estimated to be 164 mSv for 3 years at the sampling location.

CONCLUSION

To confirm the cause of the dose enhancement near the surface of a brick sample taken from Odaka, Minami-Soma City, Japan, a Monte Carlo calculation was performed using PHITS code and the calculated results were compared with measurements. The calculated results agreed well with previously published measured data. The dose enhancement at the brick surface in the measured data was explained by the beta-ray contribution, and the gentle slope in the dose profile deeper in the brick was due to the gamma-ray contribution. The calculated result estimated the skin dose to be 164 mGy (164mSv) over 3 years at the sampling location.

Source: https://academic.oup.com/jrr/advance-article/doi/10.1093/jrr/rrx099/4827065

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Long-Term Exposure to Low-Dose Radiation and Cancer: Dr. David Richardson at the Hiroshima Peace Institute (EN & JP)

 

The initiation of the Manhattan project in 1943 marked the emergence of the discipline of health physics and an expansion of research on the health effects of ionizing radiation. The health effects of occupational exposure to radiation were viewed from different perspectives by different members of the Atomic Energy Commission (AEC). There were those with immediate concerns and a focus on issues related to wartime production and health effects which were definite biological changes which are immediately evident or are of prognostic importance to health. Others had an interest in a more general understanding the effects of radiation on human health, including long term and genetic consequences. There were also managerial concerns, which persist today; Stafford Warren, medical director of the program, encouraged health research to help strengthen the government’s interest in case of lawsuits or demands for workers’ compensation. These concerns motivated a large scale epidemiological program of research on nuclear workers. Beginning in the mid-1980’s, numerous publications on cancer among workers at nuclear facilities appeared, mostly in the US and UK. Risk estimates from individual studies were uncertain, with wide confidence intervals; and, positive associations between radiation and cancer were observed in some, but not all cohorts. To summarize results across studies and improve statistical precision, pooling projects were undertaken. This lecture reviews the history of these pooled studies and then presents results from the most recent, largest, and most informative of these analyses, known as INWORKS. This is a combined study of 308,297 nuclear workers from the United Kingdom, France, and the United States of America. Quantitative results are presented and the strengths and limitations of INWORKS are discussed. (Lecture at Hiroshima Peace Institute, 30 November 2017)

The Bioaccumulation of contamination in plankton

Capture du 2018-01-18 12-01-02.png

 

Quote (emphasis added) “Page 59. The problem of radioactive particles falling into the ocean raises the question of their availability to this portion of the biosphere. Plankton normally found in sea water are consumed in large quantities by fish.
These plankton concentrate mineral elements from the water, and it has been found that radioactivity may be concentrated (Page 60) in this manner by as much as a thousand fold. Thus, for example, one gram of plankton could contain a thousand times as much radioactivity as a gram of water adjacent to it. The radioactivity from these plankton which form a portion of fish diet tends to concentrate in the liver of the fish, and, if sufficiently high levels of contamination are encountered, could have a marked effect upon the ecology of an ocean area.
end quote

Radiation risk in home construction materials

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By ALIZA SHAH – January 2, 2018 @ 6:56am
 https://youtu.be/yzY8d40dslk
NUCLEAR and radiation experts are cautioning the public over potential hazards posed by naturally-occurring radioactive elements in construction materials.
Commonly found in materials naturally sourced from earth, uranium and thorium are Naturally Occurring Radioactive Materials (NORM) often found in bricks, cement blocks, granite, marble or glazed tiles used in the construction of homes.
The two elements (uranium and thorium) undergo a natural decaying process to form other harmful elements and emit several types of radiation, particularly alpha, beta or gamma rays.
Atomic Energy Licensing Board (AELB) director-general Hamrah Mohd Ali, in an exclusive interview with the New Straits Times, cautioned that excessive exposure to these rays could damage human tissue and cells, and cause health issues or death.
The degree of health risks for those exposed to these types of radiation, he said, depended on the levels and duration of exposure.
He said the risk of excessive exposure could be reduced by minimising direct contact with NORM, including wallpaper, plastic or wooden flooring for protection and in the case of gamma, lead.
“Materials traced to natural materials like brick, mosaic, granite or cement blocks… even toilet bowls, contain radioactive materials… There is no way for us to run away from them.
“The levels of radiation vary depending on the origin of the materials.
“For example, mosaic from Kerala, India, may have higher radiation levels than those from the domestic market because the earth in Kerala has higher natural background radiation.
“Exposure to radiation can have long-term, short-term or acute effects…
“We must be careful with the long-term effects because it can slowly kill us even though we may not realise it.”
Hamrah said the types of radiation emitted from radionuclides would also determine the severity of the health effects on those exposed to it.
“Different rays affect us differently. For example, although alpha rays can be blocked using things like a piece of paper, it could cause a lot more damage on a surface, compared with beta, which has smaller particles.
“Since alpha’s particles are bigger, they will affect a wider area when it enters the human body, including through wounds, inhalation or contaminated food.
“For example, if you knead dough directly on top of a chipped granite table top, you will not notice particles containing NORM attaching to it.
“When you consume it, these radioactive materials will enter your body… some might exit through the excretion process, but the rest will continuously emit rays that will kill your cells.”
He said the International Atomic Energy Agency had set 10 microsievert as the “acceptable” yearly “dose limit” to radiation absorption.
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The “legal effective dosage” limit or level of radiation reading among the public should be no more than one milisievert a year.
Hamrah, however, cautioned about possible “unknown” effects, even with the most minimal exposure.
“Although the ‘acceptable’ dose has been set at one milisievert per year, those working in the radioactive and nuclear industry are ‘allowed’ to be exposed to up to 20 milisievert per year… This is on top of the background reading.
“But, there is no study that can say for sure that if you receive below one milisievert, you will not be affected,” he said, adding that children would be more sensitive to radiation as their immune systems were not fully developed.
He said apart from the dangers of being exposed to lethal radiation, uranium and thorium also produced radon and thoron, which are also lethal gases.
Radon, a colourless and odourless radioactive gas, is known as the second leading cause of lung cancer in the United States, with an estimated 20,000 deaths a year.
Hamrah cautioned that having more sources containing radioactive materials in a confined area would increase the level of these naturally-produced radioactive gases.
“Uranium and thorium in consumer products will continue to decay, releasing radon and thoron that will accumulate in confined areas.
“Radon in the air will break down into tiny radioactive elements (radon progeny) that will be lodged in the lining of the lungs. It will then release radiation, which can lead to cancer.
“The production of radon and thoron is continuous… meaning, if your house contains more materials that emit radiation, the reading may be higher compared with houses made of wood or with wooden flooring or roofing.”
The US Environmental Protection Agency recommends that radon readings are brought to below four picocuries per litre (pCi/L), although there is no “safe levels” for radon and thoron.
Hamrah shared with NST readers how to manage the gases: make sure your homes are well ventilated. It helps to “dilute” them.
“It is important for homes to have good ventilation. Open the windows, turn on the fan, as this will help remove the gases,” he said, adding that radon would remain in a confined area for four days before it dissipated.
As these gases are continually produced, good air circulation will help channel them out of confined areas.
AELB, Hamrah said, did not monitor the NORM level in soil or imported construction materials.
“The public can lodge a report with the agency if they suspect that the level of radon in their house is high, and we can help them verify it.
“We don’t monitor construction materials, including those from other countries, because Malaysian homes are usually well-ventilated.
“Radon is a huge concern in countries with four seasons because when it is cold, people will shut doors and windows, leaving no room for the air to flow out.
“We will take action if we receive any reports.”

Fears of children who have to check radiation levels outside before they can go and play

The main problem is internal radiation thru food and drinking, which in this article is not enough emphasized. Plus there is no safe level of manmade radiation.
they say that food
Almost seven years after the Fukushima disaster, staff are forced to check if schoolyards are too poisonous to play
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Pupils have to scan their school playground
Children are still using Geiger counters to test for deadly radiation levels at schools struck by the Fukushima disaster in Japan.
Almost seven years after the worst nuclear meltdown in decades, staff are forced to check if schoolyards are too poisonous to play.
A large Geiger counter in their playground measures the invisible threat still hanging over them after the nearby nuclear plant was hit by an earthquake and engulfed by the ensuing tsunami.
If radiation readings are too high, the children are told they cannot go outside.
Students even have their own handheld devices to check for themselves if schoolyards are too poisonous to play in.
One, 13-year-old Yume, admits what many others also feel. “I’m afraid I’m going to get cancer,” she says bluntly.
Her classmate Mei adds: “Some of the playgrounds near here have been shut – the radiation is too high.”
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Device shows readings equal to having a chest x-ray
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Explosion at the Fukushima No. 1 nuclear power station on March 14, 2011
The disaster in March 2011 was the worst nuclear incident in 30 years. Now students spend lessons scanning their school and plotting hotspots on a map back in class.
Ryu, 13, explained: “The trees are where the highest readings are. We picked up 0.23 last month.”
That level is double the 0.1 millisieverts patients face during a chest X-ray, or equal to 50 scans at the dentist.
While those last just seconds, these children are exposed constantly. The Japanese government has declared Fukushima safe, with a 20-mile no-go zone around the crippled power station itself.
Science teacher Takahira Abe, 52, leads workshops designed by Save the Children to educate about the dangers.
He said: “Fukushima will be a shadow these children live with for the rest of their lives. Most were so young life seems normal, but often when we teach them about radiation they get flashbacks.”
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Kids in the area are more likely to get cancer
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Science teacher Takahira Abe
They are taught about monitoring radiation in local crops and fish.
Mr Abe explains: “I want them to understand the risks – and that they are more likely to get cancers. It gives them tools to protect against further dangers.”
After the disaster Mr Abe and his wife Hiromi decided not to flee – despite protests from their son and daughter, then nine and 13. He said: “The school had a geiger counter for science, so I took readings. Levels were not too high.
“My duties as a teacher were more important. I had to stay and educate others.”
His textbook was created by Save the Children to help those living under a radiation threat. And counsellors have been brought in to help deal with mental health issues.
Mr Abe adds: “That’s one positive – we’re encouraging children to talk openly. That’s not happened before in Japan.”

 

The Occupation and Glass Badges

It is an article five years ago. But very important so I will post again.

—”Why are children and pregnant women, who are not inside nuclear power plants, wearing these badges? The proposal came from the National Cancer Center of Japan, which suggested to both central and Fukushima regional governments the use of dosimeters “to calm the anxiety of the children and their guardians.”

 

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by TOMOE NAGANO
 
(日本語による原文は下記に掲載)
 
Today, children in Fukushima are mandated to wear radiation dosimeters called ‘glass badges.’ Some of the regional governments also require pregnant women to wear them. They are a durable, modified version of film badges, one of three main types of radiation monitors: -alarm meters, film badges, and pocket dosimeters – all used by the workers in nuclear power plants.
 
Why are children and pregnant women, who are not inside nuclear power plants, wearing these badges? The proposal came from the National Cancer Center of Japan, which suggested to both central and Fukushima regional governments the use of dosimeters “to calm the anxiety of the children and their guardians.” The Cancer Center, prior to giving badges to children, had monitored radiation exposure on public health nurses who went to the vicinity of the Fukushima Daiichi to give medical care to the residents. Under this project, the nurses, most of whom are women, were turned into radiation monitoring devices. The Center’s official report of the project clearly states that “[the public health nurses are] to become representatives of local residents for monitoring radioactivity.”1 Since the nurses had capacity to go about every single house in the region to check health condition of the residents, the Cancer Center supposedly tried to check radiation exposure of the people by taking advantage of their role.
 
Every three months, the glass badges are collected from the people by various research institutions, universities and specialized companies2, who then would gather the data to report to the Cancer Center. However, aside from collecting the data, the Center as well as any other governmental agencies never give the people any advice as to how to protect themselves from exposure to radiation and how they can deal with health damages caused by radioactive materials. After reporting the levels of exposure, they neglect to offer any health management and support and leave them up to local governments. On the other hand, there is a person who advocates a very simple method to protect oneself from radiation; the representative being Dr. Shun-ichi Yamashita. His simple and honest advise is: “you will not get damage of radiation as long as you are smiling. You only do if you worry.” (There is a Japanese saying ‘Fancy may kill or cure’ – the very word that the former PM Yasuhiro Nakasone had said during his visit to Hiroshima Atom bomb casualty Hospital, trying to calm the minds of hibakusha he met there. Nakasone, known to have passed the very first budget for nuclear power plants in Japan during his term, always promoted nuclear energy.
 
Being a hibakusha nisei or the son of a hibakusha, Shun-ichi Yamashita is a doctor with various entitlements, who took the position of the Radiation Risk Advisor in Fukushima after 3/11, then was appointed for the vice president of the Fukushima Medical College. He also received the 2011 “Asahi Cancer Award,” which is supposed to be given to those who contributed to cancer treatment, presented by Japan Cancer Society, many of whose faculty are appointed from the National Cancer Center. This particular award was co-presented by the relatively liberal newspaper Asahi Shimbin, which came as a surprise and disgust to many, especially since Yamashita’s overly unscientific remarks had been a topic of ridicule even among mass-media.
 
As I described above, the residents of Fukushima today are made into the subjects of human experiments by the Japanese government, research institutions as well as mass-media that support their stance. In a TV report by WDR (Westdeutscher Rundfunk) in Germany, a school teacher, who hands out the glass badges to his pupils, says: “I’m not happy with these dosimeters. They are going to turn our students into study subjects. The dosimeters only accumulate data in them, instead of displaying the levels of radiation. I wish they were radiation alarms which warn you when you have to get out of the area.”
 
The people of Fukushima are expropriated of their health data without being provided with care or treatment. The very situation reminds me of what had been done to hibakushas in Hiroshima and Nagasaki under the US military occupation.
 
In August 1945, atomic bombs were dropped in Hiroshima and Nagasaki, thereby many people were killed and exposed to radiation through the thermic rays and radiation. About a year later, the occupying US military under the order of Harry Truman founded ABCC (Atomic Bomb Casualty Commission) under auspices of the military regime, in order to prepare for the future nuclear wars. At the newly set-up research facility in Hiroshima, ABCC began researching the effects of radiation on human bodies. The United States Atomic Energy Commission (AEC) stated as follows: “The bombings of Hiroshima and Nagasaki provided an exceptional and unique opportunity to monitor the effects of radiation on human groups.3” Although the ABCC collected data and human biological samples from the victims, they never provided any kind of treatment. The focus of their research was the effects on DNA. And this required the development of dynamic statistics of population, the institutionalization of pregnancy/birth registration and the establishment of public health office. Therein, crucially needed for the research was the role of mid-wives, who were to be ordered to record and report in detail the conditions of pregnancy, birth, and the newborn, and if they were safely delivered or miscarried. The research was also targeted on pregnant women and children of the resident ethnic Koreans and other foreigners. It goes without saying that the Japanese government was co-opted to this crime.
 
A woman from Fukushima stated at a rally last summer: “the people of Fukushima have become the subjects of a nuclear experiment. Vast amount of radioactive waste will remain. In spite of the huge sacrifice, the clout of the proponents of nuclear power prevails. We have been abandoned. (…) We are ‘the demons of the northeast’ quietly burning flames of wrath.” There are quite many who understand the meaning of having glass badges attached on their bodies. Thus the people in Fukushima ought to become demons. Not another person, child or woman should be exploited by the development of nuclear military industrial complex.4
 
We must recall the following phrases over and over again:
 
It was not that the victims were never given explanation about the research. However, one might wonder if there were any agreements between the researchers and the victims over the purpose of the research. What kind of resulting reports were given to the victims? Were they ever informed how the results from the experiments were used?
 
During the time [of the nuclear research], no adults ever accused the cruelty of the bomb causality research, nor they told their children what it meant. In this sense, the adults were responsible as well.
 
(from Masao Sasamoto, Atom-Bomb Research Under the US Military Occupation)
 
 
2 One of the companies, Chiyoda Technol, is a corporation whose facility is build in Rokkasho, Aomori Prefecture, under the support from both Central and Aomori governments. They are proponents of nuclear energy.
 
3 Hewlett, Richard G. and Oscar E. Anderson Jr. The New World, 1939-1946, (History of the United States Atomic Energy Commission, Vol.1), University Park, 1962.
 
4 In Manhattan Project even before the dropping of the atomic bombs, the people were made into subject of human experiments where they were injected with plutonium to see its effects. (Albuquerque Tribune, Manhattan Project: Human Plutonium Injection Experiments)

The Japanese Government Is Lying to the International Community: the Radiological Situation in and around Fukushima is NOT Safe

A report from NIRS (Nuclear Information and Resource Service, in USA)
The Japanese government has created foreign language websites which provide the information about radiology in general and the radiological situation in Fukushima. Journalists around the world, our friends and acquaintances living abroad are continually asking us whether the information that these Japanese central and local government websites present to the international community is correct or not. The following is our answer.
 
Appeal from a Japanese Anti-nuclear Activist Etsuji Watanabe
Nov.29 2017 Revised (Oct.12 2017)
Etsuji Watanabe: Member of the Japanese anti-radiation citizen-scientist group ACSIR (Association for Citizens and Scientists Concerned about Internal Radiation Exposures)
Special thanks to Mrs Yuko Kato, Mr Ruiwen Song, Ms Nozomi Ishizu, Mrs Kurly Burch, Ms Jennifer Alpern, and Mark Bennett Yuko Kato: Evacuee from Fukushima, member of the Kansai plaintiff group for compensation against TEPCO and government Ruiwen Song: Taiwanese freelance journalist.
The Japanese government has created foreign language websites which provide the information about radiology in general and the radiological situation in Fukushima. Journalists around the world, our friends and acquaintances living abroad are continually asking us whether the information that these Japanese central and local government websites present to the international community is correct or not. The following is our answer.
 pic-1.png
[Question 1]
The stories uploaded on these websites give people the impression that worrying about radiation is unnecessary. As for this impression, has Fukushima now really become a safe place to live or visit?
[Answer]
First of all, Japanese anti-nuclear activists and evacuees from contaminated areas in Fukushima and Kanto, have been warning people all over the world NEVER to trust what the Japanese government is saying about both radiology in general and the specific radiological health effects caused by the Fukushima Dai-ichi nuclear power plant disaster (hereafter Fukushima accident) following the Great East Japan Earthquake and Tsunami on March 11th, 2011.
Prime-minister Shinzo Abe and the Japanese government as a whole including Fukushima prefectural government have repeatedly declared that “with regard to health-related problems (of the Fukushima accident), I (Abe) will state in the most emphatic and unequivocal terms that there have been no problems until now, nor are there any at present, nor will there be in the future.” (Abe’s statement at a news conference). See the Japanese government website here.
This claim is completely fabricated and false. In making these claims, the Japanese government is blatantly ignoring the vast number of studies in radiological sciences and epidemiology that have been accumulating historically. By engaging in this behavior, the Japanese government has been systematically deceiving the public, both nationally and internationally.
Just think of the amount of radioactivity released during the Fukushima accident. As you know, one of the standards used to assess the extent of radioactive releases and longtime human health effects is the levels of cesium 137 (Cs137) released into the environment. Based on the Japanese government data (which is an underestimate), the Fukushima accident released 168 times the Cs137 discharged by the atomic bomb dropped on Hiroshima. This amount is almost the equivalent to the total atmospheric nuclear explosions conducted by the United States on the Nevada test ground. The Nevada desert is not designated as a residential area, but the Japanese government has recommended evacuated residents return to live in areas with radiation levels of up to 20 mSv/year. By removing economic support for evacuees, the Japanese government has forced many people who had evacuated from these areas to return.
We estimate that in the Fukushima accident approximately 400-600 times the Cs137 were released into the atmosphere by the atomic bomb blast in Hiroshima. Roughly 20% of the Cs137, or 80-120 Hiroshima-equivalents, were deposited on Japan. Of this, the decontamination efforts have only been able to retrieve five Hiroshima-equivalents. The waste from decontamination efforts is typically stored all over Fukushima mostly in mountainous heaps of large plastic bags. This means that 75-115 Hiroshima-equivalents of Cs137 still remain in Fukushima, surrounding prefectures, and all over Japan.
In addition, the Japanese government is now planning to reuse the retrieved contaminated soil under 8000Bq/kg in public works projects all over Japan. This self-destructive program has now been partially started without any announcements as to where the contaminated soil are and will be reused, under the pretext of “avoiding damage caused by harmful rumors”. This project is tantamount to scattering lethal fallout of Cs137 equivalent to about 5 times that of Hiroshima bomb all over Japan. The Japanese government is literally behaving like a nuclear terrorist.
Do you really imagine that Fukushima prefecture and surrounding areas, contaminated as they are to levels similar to the Nevada test site, is really a safe place for people to permanently live, or for foreign tourists to visit and go sightseeing?
Regrettably, we must conclude that it is not, for either residents or tourists the situation in Fukushima is not safe.
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[Question 2]
These websites also point out that the international annual dose limit for the public is at 1mSv, but this level is easily exceeded by only one CT-scan, insinuating that this 1mSv standard is set too low and thus not a useful indicator.
[Answer]
CT-Scans are often cited as if they had no radiation risks, But this is not true. A recent study clearly shows that every CT-scan (about 4.5mSv irradiation) increases the risk of cancers in children by 24%. See the website here.
In Fukushima the allowable level of radiation per year for residents is now 20mSv. Can you imagine having 4-5 CT-scans every year?
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[Question 3]
One of the websites states: “In Fukushima, the indoor radiation doses are now so reduced that no radioactive cesium can be found in the air. Therefore, no radioactive particles can invade the human body during breathing.” What do you think of this statement?
[Answer]
The Japanese government also ignores the long-term peril caused by “hot particles” ――micron-and- nano-sized radioactive particulates――which, if inhaled or absorbed into the human body, may lead to many kinds of cancers and other diseases including cardiac failure. We should consider internal irradiation to the cells near the radiation sources to be 500 times more dangerous than external irradiation because particles inside the body radiates very near or even inside cells, causing intensive damage to DNAs and other cell organs such as mitochondria.
 
[Question 4]
These websites explain that there exists not only artificial but also natural radioactivity, thus people are living in an environment surrounded by radiation all the time in everyday life.
[Answer]
One of the main tactics that the Japanese government often uses to propagate the “safety of low level irradiation” is to compare artificial radioactivity with natural radioactivity. But this logic is a methodological sleight of hand. It is crystal-clear that even exposure to natural radioactivity has its own health risks. Cancers sickened and killed people long before artificial radioactivity was used. For example, Seishu Hanaoka, one of the founders of Japan’s medicine, carried out 152 breast cancer surgeries from 1804 to 1836.
Both kinds of radioactivity have their own health risks. Risks caused by artificial radioactivity should not be compared but be added to the natural radioactivity risks as they both lead to the accumulation of exposure.
For example, potassium 40 (K40) is a typical natural radioactive nuclide. According to  the Japanese government, the average internal exposure dose for adults from K40 is about 4,000Bq/year or 0.17mSv/year. See the website here (in Japanese).
The ICRP risk model (2007) allows us to estimate the approximate risk posed by K40. The calculation shows that K40 is responsible for approximately 4,000 cancer cases and 1,000 deaths every year. If the same amount of radiation was added to that of K40 in the human body by artificial sources, the cancers and mortalities would be doubled to 8,000 and 2,000 a year, respectively. Based on the ECRR (2010) model, which criticizes the ICRP risk model as a severe underestimate, these figures should be multiplied by 40, reaching 320,000 and 80,000, respectively.
The extract you cite from the Fukushima government website is completely fake: “In Fukushima, the indoor radiation doses are now so reduced that no radioactive cesium can be found in the air. Therefore, no radioactive particles can invade the human body during respiration”. Reports from civic radiation measurement stations refute this claim. For example, dust collecting paper packs of vacuum cleaners used in Iwaki City, Fukushima prefecture, are radiologically measured and 4,800-53,900Bq/kg radioactive cesium was detected in Oct-Dec 2015. See the website here (in Japanese).
 
[Question 5]
One of the websites says that the Fukushima prefecture has conducted whole-body counter screenings of the 170,000 local population so far but cesium was rarely detected.” Does this mean that we can safely consume food from Fukushima, and Fukushima residents are no longer being exposed internally to radiation?
[Answer]
This is a typical example of demagogy by the Japanese government: vague expressions lacking specific data, using the words “safe and secure” without clear explanation. In reality, the government has not publicized any data indicating serious irradiation of the population. For example, you mentioned the Fukushima prefectural government website saying that whole-body counter screenings of 170,000 members of the local population have found radioactive Cs only in very few cases. However, the fact that no specific number is given makes the statement suspicious.
These statistics, more than likely, exclude many firefighters or other municipal employees who, at the time of accident, helped local residents evacuate from a lot of contaminated areas surrounding the defunct Fukushima plant. These people were subjected to serious radiation doses.
Civic groups’ efforts for the disclosure of information has recently prompted city officials near the defunct plant to disclose the fact that it conducted whole-body counter check-ups on about 180 firefighters, nurses and municipal employees. According to Koichi Ohyama, a member of the municipal assembly of Minami Soma, the screening conducted in July, 2011, showed almost all of these people tested positive in Cs. The maximum Cs137 dose among the firefighters was as high as 140,000 Bq. This data reveals a part of the reality of irradiation but it is only a tiny part.
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[Question 6]
The government websites suggest that no health effects from irradiation have been reported in Fukushima. Is this true? Or have any symptoms appeared that indicate an increase in radiation-induced diseases in Fukushima?
[Answer]
One example is the outbreak of child thyroid cancer, but the Japanese government has been denying the relationship with irradiation from radioactive iodine released from the Fukushima disaster.
Japan’s population statistics reflect the health effects from the Fukushima disaster radioactivity. The following data clearly show that diseases increasing in Fukushima are highly likely to have been radiation-induced.
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[Question 7]
The Fukushima prefecture website says, “After the Fukushima accident, the Japanese government has introduced the provisional standards for radioactive iodine and cesium. The Fukushima prefectural government subsequently strictly regulated distribution and consumption of food with levels of radioactivity exceeding the provisional standards. Now we have had this new much stricter standard. The distribution and consumption  of food exceeding this new standard has been continuously regulated; therefore any food on the market is safe to consume.” Is it true?
[Answer]
As for food contamination, the Japanese government has also tried to cover up the real picture. First, the current government standard for radioactivity in food, 100Bq/kg, is dangerously high for human health, especially for fetuses, infants, children and pregnant women. Even six and a half years after the accident, the Agriculture Ministry of Japan as well as many civic radioactivity measurement stations all over the country have reported many food contamination cases, although the frequency is evidently reduced. See the website here.
The Japanese government has underestimated the danger presented by internal irradiation. But, we must consider two important factors. (1) The wide range of difference in personal radio-sensitivity. According to Professor Tadashi Hongyo (Osaka University Medical Faculty), the maximum difference is as wide as 100 times in terms of biological half-life of Cs137. (2) Recent studies denying that the so-called biological half-life decrease curve actually exists. According to the new model, daily food contamination can cause concentrations to accumulate as time passes. Even a daily 1Bq internal radiation dose from food cannot be safe for human health (details below).
Our recommendation is to be cautious of food or produce from Fukushima and the surrounding areas, and, even if contamination levels are said to have now generally decreased, to avoid jumping to the conclusion that all the food is fit to eat.
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[Question 8]
We would like to ask about the situations in prefectures surrounding Fukushima. A television program once reported, “As for the safety of Tochigi and Gunma prefectures, few people are raising concern about health effects of radiation.” Is it true that the prefectures somewhat distant from the Fukushima Daiichi plant are now safe with no human risk?
[Answer]
Regarding the radioactive contamination in prefectures surrounding Fukushima, you can refer to the following website.
This article examines the contamination in the Tokyo metropolitan area, but conditions are the same or more serious in Tochigi or other prefectures north of Tokyo, nearer to the defunct Fukushima Daiichi plant.
Another example is the statistics of stillbirth and neonatal mortality in Fukushima and the surrounding five prefectures (Tochigi, Gunma, Ibaragi, Miyagi, Iwate) shown here.
Perinatal mortality in not only Fukushima prefecture but also neighboring prefectures rose 15.6% just 10 months after the accidents. This clearly indicates the existence of some kind of human health damage from radiation.
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[Question 9]
We would like to ask about the decontamination efforts by famers living in Fukushima and neighboring prefectures. Should we think highly of the farmers measuring the amount of radiation deposited on the surface of soil to create radiation maps for farms, or washing the radiation from the surface of every single tree off the radiation with high-pressure washers? The farmers said that while these methods have been shown to be radiologically effective, their produce did not sell well, because consumers are still feeling anxious about health risks. Does the problem of radioactive food contamination in Japan just end up in whether each consumer personally believes it safe or not?
[Answer]
We must raise a question that, despite the government’s decontamination efforts, a huge amount of radioactive materials deposited in mountainous areas remain untouched. Now they are re-dispersing and re-depositing over wide areas of Fukushima and surrounding prefectures via winds, cars, trains, river water, pollen, spores, emissions from incinerators, in the form of radioactive dusts and particulates, among many others. For an example, see the following website.
So I regret to say that, although these farmers’ endeavors you mentioned are very precious and respectable, they are not sufficient to completely eliminate the risk of radiation exposure from food. The problem exists objectively in the nuclear materials deposited on and in soil, algae, plants, houses, buildings, forests, animal and human bodies, not subjectively in the consumers’ sentiment or psychology.
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[Question 10]
Japanese experts have recently pitched a cultivation method that can remove cesium by intensive use of potassium fertilizer. Is this method effective at all? Do you have any doubt about their claims?
[Answer]
They seem to be among those experts who have been criticizing the general public’s tendency to demand “zero irradiation risk” as an obstacle to Fukushima reconstruction.
As you know, cesium (Cs) has chemically similar characteristics to potassium (K). So it is true that higher levels of application of potassium fertilizer lowers the plant’s absorption, and therefore concentration, of radioactive Cs, decreasing Cs137/134 concentrations in produce, often to below the government standard of 100Bq/kg. But the following problems remain: (1) This procedure can prevent Cs transfer from the soil to produce only partly, not completely; (2) This process raises the potassium concentration in the produce and therefore heightens the burdens on certain human organs such as kidneys, the heart and the nervous system, causing new health risks; (3) Heightened concentration of potassium also leads to the heightened concentration of radioactive K40, so the reduced risk of radioactive Cs lead to an increased risk of internal irradiation by K40.
 
[Question 11]
Even if cesium concentration was reduced by applying more potassium fertilizer than usual, strontium contamination would remain. In Japanese government’s international press campaign as to the Fukushima accident, almost nothing has been said about strontium. If you have any information on strontium contamination, let us know.
[Answer]
We regret that the information about strontium that you are asking for is very limited and searching for it is also a challenge for us. The Japanese government and research institutes under the government have reported very limited data regarding strontium contamination. But it is important that the Japanese government admits the fact of strontium contamination within 80km from the defunct Fukushima plant. See the website here.
Did you know that the US Department of Energy data on the strontium contamination of soil in Japan and its visualization (in Japanese)  can be seen on the websites here?
 
[Question 12]
Some Japanese experts say, “the Japanese government has declared that no health effects from irradiation below 100mSv (or 100mSv/year) have been confirmed.” Some farmers have established a private food standard of 20Bq/kg, much lower than the Japanese government standard of 100Bq/kg. Do you think that doses under 100mSv or under 20Bq/kg are safe and secure?
[Answer]
As you mentioned, the Japanese government claims that no scientific studies verify that irradiation of 100mSv or less poses a threat to human health, suggesting that irradiation under 100mSv has no risk. This, however, is false. The government is fabricating this information. In fact, very many scientific studies have already confirmed and proven health effects induced by irradiation under 100mSv. For example, see the websites below.
 
The Japanese government is using the term “100mSv” in a deliberately ambiguous and confusing manner. The expression 100mSv can have three meanings: (1) a one-time irradiation dose, (2) cumulative irradiation doses, or (3) annual irradiation doses. So 100mSv is not the same as, nor equal to the 100mSv/year that you mentioned in parenthesis. The latter amounts to a 1Sv in cumulative dose over 10 years (which is an up to 10% lethal dose), and 5Sv over 50 years (which is a 50% lethal dose). The present government standard for evacuees to return, 20mSv/year, means that living there for 5 years leads to a cumulative dose of 100mSv, at which the Japanese government admits clear health risks.
Regarding 20Bq/kg as some farmers’ private food standard, it is critical to pay serious attention to the extraction process of Cs from tissues. Japanese-Canadian non-organic biochemist Eiichiro Ochiai points out in his book “Hiroshima to Fukushima, Biohazards of Radiation” (2014) that, based on the Leggett model, the Cs concentration injected in tissues at one time diminishes relatively quickly for about 10 days in most tissues. After that, processes slow down, tending to become steady. He writes: the decrease of the overall Cs level in the body does not follow an exponential decay curve (p.83). This means that consecutive intake of Cs, even in very low levels, results in the accumulation of Cs in the body. (Incidentally, Ochiai’s book can be downloaded for free from the website below.)
Regarding the Leggett model, see the website below.
Yuri Bandazhevsky considers over 10Bq/kg of radioactive Cs concentrations in the body to be unsafe because even this low level can possibly cause abnormal electrocardiographic pattern in babies, metabolic disorders, high blood pressure, cataracts, and so on.
Therefore, we can conclude unequivocally that neither the irradiation under 100mSv nor the privately set 20Bq/kg food standard are safe and secure.
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