Fukushima radiation 'mostly fell in sea': study

Nov 17, 2011
File photo of white sandbags placed around TEPCO's Fukushima nuclear power plant. Most of the radioactive fallout from the disaster at the Fukushima nuclear plant dropped into the ocean and began circling the planet, Japanese researchers said Thursday.

Most of the radioactive fallout from the disaster at the Fukushima nuclear plant dropped into the ocean and began circling the planet, Japanese researchers said Thursday.

Up to 80 percent of the released by the Fukushima Daiichi power plant landed in the Pacific and made its way into other oceans around the world, scientists at the Meteorological Research Institute said.

"The rest has fallen on land" in and around Fukushima, said Hiroshi Takahashi, a researcher at the institute in Ibaraki, northeast of Tokyo.

"The results mean the ocean was more contaminated than land, although recent data have shown that ocean pollution resulting from the accident was well below levels affecting humans," Takahashi said.

Researchers say the radioactive materials, including caesium-137, an isotope with a half-life of more than 30 years, were widely dispersed when they entered the oceans and each particle would measure less than one micrometer -- one seventh the size of a human .

Using , they calculate the material was first blown northeast over eastern Russia and Alaska, before falling into the Pacific and reaching the western coast of the mainland United States around March 17, Takahashi said.

The materials were believed to have completed their first around-the-globe trip by March 24, he said, adding that the results would be presented to an academic meeting in Nagoya, central Japan.

Several previous studies, including one produced in France last month, have concluded the fallout had been hugely diluted by and, except for near-shore species, posed no discernible threat.

Japan has been on alert for the impact of radiation since an earthquake and resulting tsunami struck the northeast of the country on March 11, crippling the Fukushima Daiichi .

Its cooling systems were knocked offline and reactors were sent into meltdown, resulting in the leaking of radiation into the air, oceans and food chain.

Explore further: US delays decision on Keystone pipeline project

add to favorites email to friend print save as pdf

Related Stories

Some land in Japan too radioactive to farm: study

Nov 15, 2011

Farmland in parts of Japan is no longer safe because of high levels of radiation in the soil, scientists have warned, as the country struggles to recover from the Fukushima atomic disaster.

Japan finds radiation traces in whales

Jun 15, 2011

Japanese whale hunters have found traces of radioactive caesium in two of the ocean giants recently harpooned off its shores in the Pacific Ocean, a fisheries agency official said Wednesday.

Mountains limited spread of fallout from Fukushima

Nov 14, 2011

A map of radioactive contamination across Japan from the Fukushima power plant disaster confirms high levels in eastern and northeastern areas but finds much lower levels in the western part of the country, thanks to mountain ...

Areva to set up treatment system at Japan plant

Apr 19, 2011

French nuclear group Areva said Tuesday it will set up a system to treat radioactive water from a quake-hit Japanese power plant to allow power supplies and cooling systems to be repaired.

Fukushima nuke pollution in sea 'was world's worst'

Oct 27, 2011

France's nuclear monitor said on Thursday that the amount of caesium 137 that leaked into the Pacific from the Fukushima disaster was the greatest single nuclear contamination of the sea ever seen.

Recommended for you

US delays decision on Keystone pipeline project

15 hours ago

The United States announced Friday a fresh delay on a final decision regarding a controversial Canada to US oil pipeline, saying more time was needed to carry out a review.

New research on Earth's carbon budget

21 hours ago

(Phys.org) —Results from a research project involving scientists from the Desert Research Institute have generated new findings surrounding some of the unknowns of changes in climate and the degree to which ...

User comments : 0

More news stories

Magnitude-7.2 earthquake shakes Mexican capital

A powerful magnitude-7.2 earthquake shook central and southern Mexico on Friday, sending panicked people into the streets. Some walls cracked and fell, but there were no reports of major damage or casualties.

There's something ancient in the icebox

Glaciers are commonly thought to work like a belt sander. As they move over the land they scrape off everything—vegetation, soil, and even the top layer of bedrock. So scientists were greatly surprised ...

Health care site flagged in Heartbleed review

People with accounts on the enrollment website for President Barack Obama's signature health care law are being told to change their passwords following an administration-wide review of the government's vulnerability to the ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.