A group of experts convened by the agency assessed the risk of various cancers based on estimates of how much radiation people at the epicenter of the nuclear disaster received, namely those directly under the plumes of radiation in the most affected communities in Fukushima, a rural agricultural area about 150 miles north of Tokyo.
Some 110,000 people living around the Fukushima Dai-ichi nuclear plant were evacuated after the big March 11, 2011, earthquake and tsunami knocked out the plant’s power and cooling systems, causing meltdowns in three reactors and spewing radiation into the surrounding air, soil and water.
Experts calculated that people in the most affected regions had an additional 4 to 7 percent overall risk of developing cancers, including leukemia and breast cancer. In Japan, men have about a 41 percent lifetime risk of developing cancer of an organ, while a woman’s lifetime risk is about 29 percent. For those most hit by the radiation after Fukushima, their chances of cancer would rise by about 1 percent.
New research finds that radiation from the nuclear plant accident in Japan in March reached California within days, showing how quickly air pollution can travel, but scientists say the radiation will not hurt people.
"Its not harmful at all," said study author Antra Priyadarshi, a postdoctoral researcher at the University of California at San Diego. The value of the study, Priyadarshi said, is understanding how fast the tiny particles of radiation traveled and how many particles made it to the United States.
From March 13 to March 20, Japanese nuclear plant operators flooded a stricken and overheating reactor in Fukushima with seawater. The process created radioactive sulfur that was vented into the air in steam.
Tests of milk samples taken last week in Spokane, Wash., indicate the presence of radioactive iodine from the troubled Fukushima Daiichi nuclear plant in Japan, but at levels far below those at which action would have to be taken, the Environmental Protection Agency said on Wednesday.
Radioactive materials in liquids are measured in pico-curies per liter, and the sample, taken March 25, showed a reading of 0.8 pico-curies, the agency said. Those numbers, it said, would have to be 5,000 times higher to reach the “intervention level” set by the Food and Drug Administration.
“These types of findings are to be expected in the coming days and are far below levels of public health concern, including for infants and children,” the environmental agency said
Plutonium found in soil at the Fukushima nuclear complex heightened alarm on Tuesday over Japan’s battle to contain the world’s worst atomic crisis in 25 years, while opposition MPs attacked the prime minister for his handling of the disaster.
Some opposition lawmakers lambasted Naoto Kan in parliament for not extending an evacuation zone around the plant. Kan said he was seeking advice on widening the area, which would force 130,000 people to move in addition to 70,000 already displaced.
Plant operator Tokyo Electric Power Co said plutonium was found at low-risk levels in five places at the facility, which was crippled by a massive earthquake and tsunami on March 11.
A by-product of atomic reactions and also used in nuclear bombs, plutonium is highly carcinogenic and one of the most dangerous substances on the planet, experts say.
They believe some of the plutonium may have come from spent fuel rods at Fukushima or damage to reactor No. 3, the only one to use plutonium in its fuel mix.
Japan’s Nuclear and Industrial Safety Agency said while the plutonium levels were not harmful to human health, the discovery could mean a breach in the reactor’s containment mechanism.
Highly toxic plutonium is seeping from the damaged nuclear power plant in Japan’s tsunami disaster zone into the soil outside, officials said Tuesday, heightening concerns about the expanding spread of radiation.
Plutonium was detected at several spots outside the Fukushima Dai-ichi power plant — the first confirmed presence of the dangerously radioactive substance, plant operator Tokyo Electric Power Co. said.
There are strong indications some of the radioactivity is coming from damaged nuclear fuel rods, a worrying development in the race to bring the power plant under control, Chief Cabinet Secretary Yukio Edano said Tuesday.
"The situation is very grave," Edano told reporters. "We are doing our utmost efforts to contain the damage."
Officials said the traces of plutonium posed no immediate threat to public health. But the latest finding appeared to feed government frustration with TEPCO, which has failed to stem the crisis more than two weeks after a March 11 earthquake and tsunami damaged the plant.
The failure to keep radioactive substances from seeping out of the facility was "deplorable," said Hidehiko Nishiyama, a spokesman for the Nuclear and Industrial Safety Agency.
The government is considering temporarily nationalizing the troubled nuclear plant operator, Japan’s top-selling daily Yomiuri said Tuesday, quoting unnamed government sources.
Driving rain on Monday disrupted rescue efforts in Japan and compounded the misery of disaster survivors now fearing radioactive fallout from the smouldering wreck of a nuclear plant.
The bad weather forced Prime Minister Naoto Kan to call off a helicopter flight to the battered northeast coast including a trip to a football training centre about 20 kilometres (12 miles) from the crippled Fukushima No. 1 plant.
The centre is now a staging area for emergency personnel working to avert a disastrous radiation release from the atomic plant, whose reactors have been overheating after cooling systems were damaged by an earthquake and tsunami.
Engineers have laid an external electricity supply to reactor number two and may be able to restore power to its control room later Monday, Japan’s nuclear safety agency said.
Crucial efforts to tame Japan’s crippled nuclear plant were delayed by concerns over damaging valuable power assets and by initial passivity on the part of the government, people familiar with the situation said, offering new insight into the management of the crisis.
Meanwhile, a regulator who was inspecting the Fukushima Daiichi nuclear-power complex when the quake hit offered The Wall Street Journal one of the first eyewitness accounts of the havoc at the site, describing how the temblor took down all communications in the area, greatly complicating the response.
The plant’s operator—Tokyo Electric Power Co., or Tepco—considered using seawater from the nearby coast to cool one of its six reactors at least as early as last Saturday morning, the day after the quake struck. But it didn’t do so until that evening, after the prime minister ordered it following an explosion at the facility. Tepco didn’t begin using seawater at other reactors until Sunday.
Japan’s efforts to contain the damage at its crippled nuclear plant suffered an unexpected setback on Sunday when pressure began rising again at the most troubled reactor, requiring the release of more radioactive gases into the air.
Nuclear regulators said that Reactor No. 3 at the Fukushima Daiichi Nuclear Power Station, some 170 miles north of Tokyo, had experienced a rise in pressure even though military and civilian firefighters had doused it with 2,400 tons of seawater for nearly 14 hours through early Sunday. The government had said on Saturday that the reactor, which contains a highly toxic fuel that includes reclaimed plutonium, appeared to be stabilizing.
In a news conference Sunday afternoon, Hidehiko Nishiyama, a spokesman for the Nuclear and Industrial Safety Agency, said that overheating inside the reactor’s containment vessel would require the venting of gases to prevent a bigger buildup.
The problem is certain to delay efforts by the Tokyo Electric Power Company and the Self-Defense Forces to restore power to the reactor’s cooling system.
"We are making progress … (but) we shouldn’t be too optimistic," said Hidehiko Nishiyama, deputy-general at Japan’s Nuclear Safety Agency.
Technicians attached a power cable to the No. 1 and No. 2 reactors, hoping to restore electricity later in the day prior to an attempt to switch the pumps on.
They aim to reach No. 3 and 4 soon after that.
If successful, that could be a turning point in a crisis rated as bad as America’s 1979 Three Mile Island accident.
If not, drastic measures may be required such as burying the plant in sand and concrete, as happened at Chernobyl in 1986, though experts warn that could take many months and the fuel had to be cooled first.
On the negative side, evidence has begun emerging of radiation leaks from the plant, including into food and water.
Police said they believed more than 15,000 people had been killed by the double disaster in Miyagi prefecture, one of four that took the brunt of the tsunami damage. In total, almost 12,000 people are missing in the northeast, where the confirmed death toll stood at more than 7,600.