Government radiation monitoring in areas near Japan’s crippled Fukushima nuclear plant is unreliable, Greenpeace charged on Tuesday, with heavily populated areas exposed to 13 times the legal limit.
The environmental group said authorities were wasting time cleaning up evacuated areas and should prioritise decontamination efforts in places where people live, work and play.
Greenpeace found that in some parks and school facilities in Fukushima city, home to 285,000 people, radiation levels were above three microsieverts per hour. Japan’s recommended radiation limit is 0.23 microsieverts per hour.
“We also found that official monitoring posts placed by the government systematically underestimate the radiation levels,” said Rianne Teule, Greenpeace’s radiation expert, adding that some machines are shielded from radiation by surrounding metal and concrete structures.
Masaharu Tsubokura, M.D., of the University of Tokyo, and colleagues conducted a study to gauge the level of radiation exposure to residents of the city of Minamisoma, located 14 miles north of the Fukushima Daiichi nuclear plant. “Release of radioactive material into the air, water, and soil raised concern about internal radiation exposure and the long-term risk of cancer in nearby residents,” they write.
Many residents were evacuated after the meltdown, but by August 2011, approximately half had returned. A voluntary screening program for levels of cesium, known to be representative of total internal radiation exposure, was conducted between September 2011 and March 2012 for all residents ages 6 years or older. Total cesium exposure was converted into committed effective dose (sievert, Sv). Common dose-limit recommendations for the public are 1 mSv or less. A total of 9,498 residents enrolled in the study, 24 percent of the registered population on August 15, 2011. The sample consisted of 1,432 children and 8,066 adults. A total of 3,286 individuals (34.6 percent) had detectable levels of cesium, including 235 children (16.4 percent) and 3,051 adults (37.8 percent). Committed effective doses were less than 1 mSv in all but 1 resident (1.07 mSv).
“To our knowledge, this is the first report on internal exposure to cesium radiation after the Fukushima Daiichi nuclear plant incident. In this sample, exposure levels were low in most adults and children tested and much lower than those reported in studies years after the Chernobyl incident. Even the highest levels of contamination observed are below the thresholds for the administration of Prussian blue [an antidote used in the treatment of cesium poisoning],” the authors write.
Kiyoko Okoshi had a simple goal when she spent about $625 for a dosimeter: she missed her daughter and grandsons and wanted them to come home.
Local officials kept telling her that their remote village was safe, even though it was less than 20 miles from the crippled Fukushima Daiichi nuclear power plant. But her daughter remained dubious, especially since no one from the government had taken radiation readings near their home.
So starting in April, Mrs. Okoshi began using her dosimeter to check nearby forest roads and rice paddies. What she found was startling. Near one sewage ditch, the meter beeped wildly, and the screen read 67 microsieverts per hour, a potentially harmful level. Mrs. Okoshi and a cousin who lives nearby worked up the courage to confront elected officials, who did not respond, confirming their worry that the government was not doing its job.
A “miniscule” amount of radiation that probably came from damaged nuclear reactors in Japan was picked up at a California monitoring station yesterday, the U.S. government said.
The level of radiation registered in Sacramento was about “one-millionth of the dose” a person gets from rocks, bricks, the sun and natural background sources and “poses no concern,” the U.S. Environmental Protection Agency and Energy Department said in a joint statement.
A similar level of the radioactive isotope, xenon-133, was detected in Washington state on March 16 and 17, according to the agencies. It was “consistent with a release from the Fukushima reactors in Northern Japan,” according to the statement. The EPA and Energy Department have monitoring systems and neither found “radiation levels of concern.”
US border agents are monitoring travelers from Japan for signs of radiation, but have found no harmful levels to date, the Customs and Border Protection agency said Thursday.
While stressing that it routinely checks all passengers arriving at US ports and airports, the CBP said it had issued guidance to border staff to pay specific attention to those arriving from Japan.
The agency "is monitoring developments in Japan carefully and is specifically assessing the potential for radiological contamination associated with" the quake and tsunami-crippled Fukushima nuclear power plant, it said.
"Out of an abundance of caution, CBP has issued field guidance reiterating its operational protocols and directing field personnel to specifically monitor maritime and air traffic from Japan," it said in a statement.
Fresh white smoke rose again Monday from Japan’s Fukushima Daiichi nuclear power plant, caused by an explosion at a building tied to the facility’s No. 3 reactor.
Japan’s Chief Cabinet Secretary Yukio Edano said that, according to the head of the nuclear facility, the container vessel surrounding the reactor is still intact. Initial reports suggest that radiation levels rose following the explosion late Monday morning, but Edano said he does not believe there has been a massive leak.
“We are now collecting information on the concentration of radiation,” he said.
Officials are reassuring the public there is no immediate danger but an exclusion zone around the facility has been extended and the evacuation of people from the area now runs into the hundred of thousands.
The 600 residents remaining within 20 kilometers (12 miles) of the plant, despite an earlier evacuation order, have been ordered to stay indoors, according to Edano.
Officials earlier said that they were operating on the presumption that there may be a partial meltdown in the No. 3 and No. 1 nuclear reactors at the Daiichi plant. Authorities have not yet been able to confirm a meltdown, because it is too hot inside the affected reactors to check.
The Tokyo Electric Power Company, which runs the plant, said in a press release late Sunday that radiation levels outside that plant remain high.
At another plant, in Onagawa, authorities early Sunday noted high radiation levels. The International Atomic Energy Agency said later — using information from officials in Japan — levels returned to “normal” and found no emissions of radioactivity” from Onagawa’s three reactors.
“The current assumption of the Japanese authorities is that the increased level may have been due to a release of radioactive material from the Fukushima Daiichi nuclear power plant” located 135 kilometers (about 85 miles) north of Onagawa, the agency said.
Food products from Japan will be tested for radiation from today, Singapore’s Agri-Food and Veterinary Authority (AVA) said on Saturday, after the nuclear fallout in Japan.
Its spokesman said it would monitor Japanese produce based on its source and potential risk of contamination. These will include fruits, vegetables, meat and seafood.
‘Samples will be taken for radiation testing and fresh produce will have priority,’ the spokesman said. ‘AVA will continue to closely monitor the situation and its developments.’
Japanese restaurants in Singapore are bracing themselves for a possible shortage of food products from Japan.
Ms Diona Hang, manager at Megumi Japanese restaurant, expects food supplies to be affected, although she will know the full extent only today when the Japanese suppliers get back to work.