Breaking news update: Cesium-contaminated mushrooms served in food (NHK, November 04)
Radioactive cesium exceeding the government standard has been found in mushrooms grown at a facility in Yokohama City, near Tokyo. About 800 people were served food containing the mushrooms from March through October.
The city says high levels of radioactive cesium were found in dried shiitake mushrooms harvested in both months. The contamination is believed to have been caused by the Fukushima nuclear accident.
The contamination in March was up to 2,770 becquerels of cesium per kilogram; in October, 955 becquerels per kilogram.
Each exceeded the government’s standard of 500 becquerels.
The facility checked the mushrooms for radioactive contamination this week after concerned citizens inquired about possible contamination in food served there.
Yokohama is around 250 kilometers from the Fukushima Daiichi nuclear plant.
The mushrooms were reportedly not sold on the market.
“Internal exposure and external exposure to radiation are technically two different things, but to those who are under threat of radiation exposure, there’s no significant difference; they’re on the receiving end of both. There’s no distinction between “internal” or “external” when it comes to fears for one’s well-being.” Read the rest here…
Nursery schools to e-mail, tweet parents in times of disaster (Yomiuri, Nov.4)
Municipalities in Tokyo and neighboring prefectures have decided to adopt Internet-based emergency notification systems to alert parents of their children’s safety during disasters, based on lessons learned from the Great East Japan Earthquake.
When the March 11 quake hit, many nursery schools were unable to contact parents who had become stranded in the transportation chaos that followed the quake.
This month, the Shinagawa Ward government in Tokyo will introduce an e-mail message system at all 41 ward-run nursery schools. Each school will register parents’ e-mail addresses on the system.
The system, which is expected to be in full operation by the end of this year, will allow the schools to simultaneously send e-mail messages to all parents confirming their children’s safety.
The system will cost the ward office about 2.1 million yen to set up and about 3 million yen annually to operate because management of e-mail addresses will have to be contracted out to protect parents’ personal information.
A Shinagawa Ward official in charge of child care services said: “During the March 11 disaster, it was difficult to contact [parents] by phone. We realized it was necessary to have other means of contacting parents.”
The Koto Ward government will introduce a similar system by the end of March, while the Setagaya and Katsushika ward governments introduced a similar system in June and September, respectively.
Many local governments choose not to set up emergency telephone lists for nursery schools, not only for privacy reasons, but also because most parents visit the schools daily to drop off and pick up their children.
However, many parents who live in suburban areas tend to work far from their homes. The March 11 disaster highlighted the need to make emergency contact with them by means other than telephone.
According to a June survey by the Tokyo metropolitan government, only half of the municipal governments in Tokyo had established an emergency contact network with parents.
The system most widely used was the disaster message system, a free service that allows people to leave telephone messages about their situation for loved ones in times of disaster.
About 40 percent of the surveyed municipalities said they were considering introducing the system.
In the hours after the quake, phone lines were down as telephone companies limited connections to prevent system overloads. However, e-mail services and Twitter were relatively easy to connect to.
On March 11, the privately run Otsuna nursery school in Yokohama posted messages for parents via Twitter, which the school had just started using.
“I was able to stay calm because I knew my child was safe,” one parent of a child who attends the school said.
After the disaster, nursery schools run by Bunkyo Ward, Tokyo, also started using Twitter.
The Yokohama city government had planned to use the disaster message system for city-run nursery schools to inform parents of their children’s safety, but it failed to work properly after the March 11 disaster because many people were unsure how to use it.
The Yokohama government is considering introducing an e-mail message delivery system as well.
Xenon at Fukushima not result of ‘critical’ nuclear reactions: TEPCO (Japan Times, Nov 3)
“It is not leading to instability of the reactor or a rise of the radiation level outside,” the utility known as TEPCO said, adding that it does not expect the incident to impact its goal of attaining a stable condition of the plant’s troubled reactors called cold shutdown.
The plant operator said it has judged that spontaneous fission, which it says occurs at a constant rate, has generated xenon-133 and xenon-135 at its crisis-hit No. 2 reactor, as a criticality would have resulted in the recording of concentration levels 10,000 times higher.
The data at hand match estimated levels of xenon produced by sporadic fission of curium-242 and curium-244 inside melted fuel, it said.
It also cited as evidence supporting its view the detection of xenon even after it poured boric-acid solution to absorb neutrons necessary for a fission reaction, and a lack of abnormal rises in the reactor’s temperature or pressure.
Xenon, which was found Tuesday from gas collected from the No. 2 reactor’s primary containment vessel, is believed to have leaked out of the fuel’s cladding tubes due to their meltdown, it said, adding that it plans to continuously monitor gas inside the furnace….” Read more here...
The head of Japan’s Nuclear and Industrial Safety Agency (NISA) was issued a stern reprimand on Nov. 2 for tardiness in delivering news to the government that the No. 2 reactor at the crippled Fukushima No. 1 nuclear plant may have briefly reached criticality.
Chief Cabinet Secretary Osamu Fujimura revealed at a news conference the same day that Minister of Economy, Trade and Industry Yukio Edano had reprimanded NISA chief Hiroyuki Fukano for failing to report the incident to both himself and the Prime Minister’s Office until almost a day after it occurred.
Radioactive xenon was detected at the reactor on the afternoon of Nov. 1, indicating the core might have gone briefly critical, and was reported to NISA by plant operator Tokyo Electric Power Co. that night. NISA, however, did not pass the news on to the PM’s office until the next morning.
“I have been told that NISA decided not to report the incident until the following morning because the agency didn’t believe it was a dangerous situation,” Fujimura told reporters at the news conference.
NISA reported the suspected core criticality to the Prime Minister Yoshihiko Noda’s secretary at just past 7 a.m. on Nov. 2, who then passed it on to the prime minister. The news reached Edano later that morning, followed by Fujimura at about 9 a.m.
Tainted bottle, soil dug up in Tokyo (JapanTimes, Nov. 4, 2011)
Workers removed soil contaminated with radium and a buried bottle believed to have contained it at a spot in Setagaya Ward, Tokyo, where a high level of radiation was detected, science ministry officials said.
The ministry reiterated Wednesday that the level of up to 170 microsieverts per hour at the spot near a supermarket was not caused by the crisis at the Fukushima No. 1 nuclear plant.
Workers placed the bottle and soil in a lead container after they dug them up. The workers have shielded the hole as radiation up to 25 microsieverts per hour was recorded even after the soil and bottle were removed, according to the ministry.
Workers were aiming to start decontaminating the area Thursday or later.
The maximum exposure limit for the general public is 1,000 microsieverts a year.
Science far from conclusive on low-level radiation risks (Japan Times, Nov. 4, 2011)
Experts just don’t know the effect on humans below 100 millisieverts
The March 11 nuclear accident at the Fukushima No. 1 plant has transformed what used to be a long-standing academic debate into an urgent issue for millions of ordinary people: Will long-term exposure to low-level radiation cause any health problems?
Experts have long been at odds over whether low-level radiation doses of less than 100 millisieverts are damaging.
Following are questions and answers on the effect of low-level radiation on human health:
How much risk does exposure to a cumulative radiation dose of 100 millisieverts present?
According to the International Commission on Radiological Protection, it could increase the cancer mortality risk by about 0.5 percent, meaning about 50 out of 10,000 people exposed to that level could die of cancer caused by the radiation.
The ICRP is an organization of scientists whose guidelines have served as the basis for radiation regulations in many developed countries, including Japan.
How afraid should we be of radiation at that level?
It depends on individual perceptions. If the ICRP is correct, it would increase your chances of dying of cancer by only 0.5 percent, but that could be a significant increase for a government responsible for protecting hundreds of thousands of people living around a nuclear plant.
For individuals, there are innumerable other factors in everyday life that can cause cancer, and doctors say improved lifestyle choices can easily offset the increased risk posed by exposure to 100 millisieverts of radiation.
In fact, various forms of cancer account for as much as one-third of all deaths in Japan, with major factors including smoking, insufficient consumption of vegetables and lack of exercise.
What about the risks of cumulative radiation doses of less than 100 millisieverts?
Results of tracking surveys of survivors of the Hiroshima and Nagasaki atomic bombings suggest exposure of 100 millisieverts does increase the cancer mortality risk, but it is unclear whether there is a link between doses below 100 millisieverts and cancer.
Scientists are split on the question of whether there are any risks below the 100-millisievert mark. Some believe 100 millisieverts is the “threshold” level under which radiation won’t harm humans. Others argue otherwise, saying there is still a risk, however small it may be.
What is the government’s assessment of the 100-millisievert risk, and how is it reflected in food restrictions?
The Food Safety Commission, a government panel consisting of independent experts, concluded on Oct. 27 that radiation above a cumulative exposure of 100 millisieverts poses a significant risk to humans, but it is difficult to draw any conclusions on the health effects from radiation less than that level.
Based on the commission’s interpretation, the Health, Labor and Welfare Ministry will lower the acceptable annual intake in food products to 1 millisievert per year from the current provisional limit of 5 millisieverts.
Is there any scientific research on radiation exposure of less than 100 millisieverts?
Fifteen nations, including Japan, the U.S., the U.K., Canada, some European countries and South Korea, have conducted research on workers at nuclear power plants for about a decade. Also, scientists studied people living in Kerala, India, well-known for its high background radiation from radioactive thorium in monazite sand.
In short, there was no statistically significant evidence to conclude exposure to less than 100 millisieverts increases the cancer risk.
Why are those studies inconclusive?
Because there are confounding — or outside — factors in getting cancer, such as smoking.
Cigarettes for example have a much stronger effect than radiation. The risk of lung cancer for smokers is 2.3- to 22.4-fold higher than that for nonsmokers, according to the Japan Health Promotion and Fitness Foundation, which cites separate studies by Japanese and U.S. groups. Those levels are far higher than the theoretical 0.5 percent risk posed by 100 millisieverts of radiation exposure.
What were the results of the research in Japan on nuclear plant workers?
The Radiation Effects Association researched 277,000 employees of nuclear plants, most of whom had been exposed to less than 100 millisieverts over an extended period.
The study found that those who were exposed to higher radiation, though still below the 100-millisievert level, saw higher cancer mortality rates, which may indicate that even low-level radiation doses pose a lethal cancer risk.
But many of those with cancer were also smokers, which may have pushed up the risk. This makes it difficult for researchers to draw a clear conclusion on the risks of low-level radiation exposure.
“Past research (on smoking, drinking and the workers’ other habits) shows those with high radiation doses tended to smoke more,” the study’s research paper concluded.
“Taking these facts into account . . . confounding bias by smoking and other habits is undeniable,” it stated.
The 204,000 men in the study had an average cumulative radiation dose of 13.3 millisieverts. Of them, 14,224 had died as of March 2009, including 5,711 who succumbed to cancer.
What was the result of the Kerala research?
In short, no correlation was found between the ambient radiation and the risk of cancer, but there was one for cigarettes. Smoking was one of the factors studied.
The study “showed no HBR- (high background radiation) related excess of malignant tumors. Although the statistical power of the study might not be adequate due to the low dose, these findings suggest it unlikely that estimates of cancer risk at low doses are substantially greater than currently believed,” a research paper stated in the January 2009 edition of Health Physics magazine.
Seiichi Nakamura of the Health Research Foundation, under the science ministry, said Kerala’s radiation level is about the same as in Iitate, Namie and other municipalities in Fukushima Prefecture that the government ordered evacuated because of the nuclear crisis. Nakamura was on the team that researched Kerala residents.
So radiation of less than 100 millisieverts won’t harm the human body?
Just because studies haven’t found a statistically significant increase in risk doesn’t necessarily prove there is no chance of an increase in the cancer rate. Some scientists argue there is a risk, even if it hasn’t been confirmed in epidemiological surveys.
The Committee on the Biological Effects of Ionizing Radiation, comprised of radiology scientists in the United States, wrote a report titled “BEIR VII” in 2006 that says “the current scientific evidence is consistent with the hypothesis that there is a linear, no threshold (LNT) dose-response relationship between exposure to ionizing radiation and the development of cancer in humans.”
Sentaro Takahashi, another researcher at the Kyoto University Research Reactor Institute, said the report is conservative because it is intended to provide a standard for protection from radiation.
He also said the report doesn’t mention whether the linear relation is statistically significant because the aim of the committee is to come up with an overall conclusion based on individual studies, each of which mention the statistical significance of their theories.
Is cancer the only health risk associated with low radiation doses?
Scientists and medical doctors say yes. Nakamura is aware of some blogs stating there has been an increase in the Kanto and Tohoku regions of heart attacks resulting in death, birth defects and cases of childhood diseases, but it is scientifically impossible any of this was caused by radiation from the Fukushima No. 1 plant because the leakage of radiation has not been high enough, he said.
70 percent in Japan want end to nuclear power (NHK, Nov 4)
An NHK poll shows that nearly 70 percent of Japanese people want to reduce or abolish nuclear power in the future.
NHK polled about 2,600 randomly selected adults nationwide over 3 days through October 28th.
1,775 people responded.
24 percent of respondents said all nuclear power plants should be shut down and 42 percent said the number should be reduced.
23 percent said the existing facilities should be maintained and 2 percent said they want more nuclear plants.
49 percent of respondents said they are very afraid of another nuclear accident and 37 percent are worried to a certain extent.
When asked if nuclear power generation will become safe in the future, 46 percent said yes and 48 percent said no.
“The start Wednesday of shipments of debris from the Great East Japan Earthquake to Tokyo, the first destination for such refuse outside the Tohoku region, was a long-awaited first step toward wider disposal of the wreckage.
However, an Environment Ministry survey released Wednesday showed that only 54 local governments and garbage-disposal unions, less than 10 percent the figure in a previous survey, were considering accepting debris from disaster-hit areas.
A huge quantity of debris remains in the devastated areas almost eight months after the March 11 disaster, and secondary damage such as fires in piles of debris has occurred. People also have voiced concern that the slow pace of disposal may adversely affect reconstruction efforts.
In Miyako, Iwate Prefecture, on Wednesday, wood, plastic and other debris were thrown by heavy machinery into containers on trucks, which then headed to a JR cargo terminal in Morioka.
Miyako Mayor Masanori Yamamoto observed the work and said: “Today’s achievement represents great progress for reconstruction. I’m grateful.”
The Iwate prefectural government and the Tokyo metropolitan government signed an agreement that Tokyo will accept 11,000 tons of debris by the end of fiscal 2011 to dispose of it. Including this figure, the metropolitan government plans to accept about 500,000 tons of debris from Iwate and Miyagi prefectures by the end of fiscal 2013.
So far, however, Tokyo is the only prefecture outside the Tohoku region that has accepted debris from the disaster-hit areas. An official involved with the issue at the Kyoto city government said, “The Environment Ministry says the debris is safe, but we can’t convince our residents.”” …Read the rest of the article here…
“A panel of the Cabinet Office’s Nuclear Safety Commission has agreed to set up new nuclear disaster management zones by tripling the radius of the present standard emergency zone to 30 kilometers around the nation’s nuclear power plants.
In a draft of its report, which the panel basically agreed upon, a key disaster management zone with a current radius of eight to 10 kilometers will be expanded to a zone with a 30-kilometer radius to be called the urgent protective action planning zone (UPZ).
In the UPZ, evacuation plans and other measures will be implemented if an accident occurs at a nuclear power plant.
Within the UPZ, a five-kilometer radius will be designated as the precautionary action zone (PAZ), from which residents should immediately evacuate in the event of a nuclear accident.
Outside the UPZ, a zone called the plume protection planning area (PPA) will be set up. In this zone, with a radius of about 50 kilometers, people will be instructed to stay indoors or will be provided with iodine pills in such an emergency.
Around the nation, the number of municipalities located partially or fully within the emergency zones will increase from the current 45 to 135 if the UPZs are established. Among prefectural capitals, the whole of Mito and part of Kyoto will be included.
The review is part of the commission’s revisions of disaster management guidelines. The commission will compile an interim report about the guideline revisions by the end of this fiscal year.
A nuclear safety agency, which will take over the commission’s duties next fiscal year, will implement the guideline revision. The municipal governments to be affected will include the new zoning in their respective disaster management plans under a basic law on disaster management.
Lessons from the crisis at Tokyo Electric Power Co.’s Fukushima No. 1 nuclear power plant in Fukushima Prefecture are behind the expansion of the disaster management zone …
The changes also include new guidelines over whether evacuation will be necessary.”
Please read our earlier spot update here.
At this point in time, many conspiracy theories are rife among the Japanese, and suspicions about media-blackout and news manipulation and control and takeover of economic concerns over humanitarian ones by political groups, concealment of information…abound. Some speculations are wild, others merit investigation. There are a couple of websites that also deal with unconfirmed reports from the populace at large such as Fukushima Diary and Ex-skf Blogspot sometimes track data from many official sources, and offer helpful translations, but also often cite or contains reports from other web sources that are less sound. Caution, discernment and judgment in sifting through information is advised.