Subscribe to our free daily newsletters
  Space Industry and Business News  

Subscribe to our free daily newsletters

Radioactive traces found in Japan tap water

Radioactive contamination of food risks: experts
Paris (AFP) March 19, 2011 - The risk from radioactive contamination of food depends on several factors but the duration of the problem depends especially on which type of radioactive element is to blame, say experts.

Japan on Saturday said that it had discovered abnormal levels of radiation in milk and spinach from areas near Fukushima, and in tap water in Tokyo and five central prefectures, but there was no threat to health.

In historical cases of contamination, the main source has been wind-borne dust which is deposited on fruit or vegetables or which falls on the soil, where it is absorbed by grass and leafy plants.

Radioactive particles are then transmitted through the food chain, which explains why cattle can have higher-than-normal levels of radioactivity in their milk and meat.

Ingested, these particles are hazardous because they release energy that can slice through molecular bonds in DNA, thus increasing the risk of cancer.

The problem can be short-term or long-term, depending on the nature of the radioactive source and the amount of contamination in the local environment, which in turn is also influenced by the weather.

Iodine 131, for instance, has a "half life" -- a measure of decay -- of only eight days, which means it is likely to break down in the environment in a few weeks.

"There is a short-term risk to human health if radioactive iodine in food is absorbed into the human body," the International Atomic Energy Agency (IAEA) said on Saturday.

"If ingested, it can accumulate in and cause damage to the thyroid. Children and young people are particularly at risk."

Taking "stable" forms of iodine, such as potassium iodide tablets, can block radioactive iodine in the thyroid, the IAEA said.

The longer-term problem comes from enduring elements such as caesium 137, whose "half life" is measured in 30 years and may even take several centuries before it breaks down totally.

Caesium fallout from the Chernobyl nuclear disaster in April 1986 caused long-term contamination problems in many European countries, leading to restrictions on the sale of milk or dairy beef as far as Scotland.

According to a 1993 study by the IAEA, more than six years after Chernobyl, farmers in some mountain areas of southern Norway, more than 1,000 kilometres (600 miles) from the disaster, were raising reindeer with up to 20,000 becquerel per kilogram (Bq/kg) of radiation, and sheep with up to 10,000 Bq/kg.

Strontium 90 is another dangerous long-term contaminant, as is plutonium 239.

Plutonium is one of the most toxic substances for man, but through direct contact rather than through food.

"Plutonium 239 is absorbed to a negligible extent from soil by plants and is very poorly absorbed from the gastrointestinal tract of animals and man," says the UN Scientific Committee on the Effects of Atomic Radiation (UNSCEAR).

The maximum dose for radioactive iodine, according to Euratom guidelines, is 150 Bq/kg or becquerels per litre (Bq/l) for infant food; 500 Bq/kg or Bq/l for dairy products; 2,000 Bq/kg or Bq/l for other foods and 500 Bq/l for liquids intended for consumption.

The maximum dose of radioactive elements lasting beyond 10 days -- thus including caesium -- is 400 Bq/kg or Bq/l for infant food; 1,000 Bq/kg or Bq/l for dairy products; 1,250 Bq/kg or Bq/l for other foods; and 1,000 Bq/l for liquids intended for consumption.

Radioactivity also exists in the natural environment, for instance as a background source that comes from certain kinds of rocks. In addition, many countries permit safe irradiation of food products to kill or prevent bacteria in order to prolong shelf life.

by Staff Writers
Osaka (AFP) March 20, 2011
Traces of radioactive substances have been detected in Japan's tap water following an emergency at a quake-hit nuclear plant, but are not a risk to human health, the government said Saturday.

Abnormal levels of radioactive iodine were found in the water supply in Tokyo and also in Fukushima prefecture, home to the plant located some 250 kilometres (155 miles) northeast of the capital, officials said.

Such readings were also made in the central prefectures of Gunma, Tochigi, Saitama, Chiba and Niigata.

Traces of radioactive caesium were also found in tap water in Tochigi and Gunma, the officials said. But these levels were also well within the safety standards for drinking water, they added.

In the Fukushima town of Kawamata, 45 kilometres from the plant, the level of iodine-131 in water was 308 becquerels per kilogramme on Thursday, 155 on Friday and 123 on Saturday, the health and welfare ministry said, demonstrating levels were going down.

The level of 300 becquerels per kilogramme is set as a threshold where the government considers advising people to limit the intake of water, ministry official Yusei Kobayashi said.

This limit is one fourteenth of an amount of radioactivity which a person is exposed to by travelling from Tokyo to New York by air, he said.

Levels of iodine-131 were far lower elsewhere -- 77 in Tochigi and 1.5 in Tokyo, the education and science ministry said.

Earlier, the government said it had discovered abnormal levels of radiation that exceeded the legal limit in milk and spinach from areas near the stricken plant, but they posed no immediate threat to humans.

The findings are nevertheless likely to fuel consumer fears in the wake of a March 11 quake and tsunami which critically damaged the Fukushima No.1 plant, sending radioactive substances leaking into the air.

earlier related report
Japan detects abnormal radiation levels in food
Osaka (AFP) March 19, 2011 - Japan has detected abnormal levels of radiation in milk and spinach near a stricken nuclear plant, but the foods pose no immediate threat to humans, government spokesman Yukio Edano said Saturday.

Traces of radioactive iodine were meanwhile found in tap water in Tokyo and several prefectures near the atomic power complex, a science ministry official said, but the levels were well below the legal limit.

The findings are nevertheless likely to fuel consumer fears in the wake of last week's quake and tsunami, which critically damaged the Fukushima No.1 plant northeast of Tokyo, sending radioactive substances leaking into the air.

"Radiation exceeding the limit under Japanese law was detected," Edano told reporters.

The contaminated milk was found in Fukushima prefecture, where the quake-damaged atomic power station is located, while the tainted spinach was discovered in neighbouring Ibaraki prefecture, Edano told reporters.

The milk was found more than 30 kilometres (20 miles) from the Fukushima No. 1 nuclear power plant -- outside the government's exclusion zone.

The spokesman said the health ministry had ordered authorities in both prefectures to check where the products came from, how they were distributed and -- depending on their findings -- suspend sales.

"The government will do its utmost... to avoid health hazards and to resolve this problem," Edano said.

"The number does not present an immediate health threat. I would like to ask you to act calmly."

He noted that even if a consumer were to drink the contaminated milk for a year, the radiation level would be the equivalent of one hospital CT scan.

An official in Fukushima prefecture told AFP that dairy farmers in the town of Kawamata, where the tainted sample was found, had been asked to refrain from shipments until further notice -- and not consume any milk themselves.

Farmers within 30 kilometres of the plant were also asked to halt shipments.

Plant operator Tokyo Electric Power Co (TEPCO) apologised for the contamination of foodstuffs and said it would look into compensating the farmers affected, Jiji Press reported.

Hideki Mukaitsubo, president of Fukushima Prefecture Minami Dairy in Izumizaki village, 60 kilometres from the nuclear plant, said he was concerned about the long-term prospects for the industry.

"We've halted shipping completely. I really don't know what to do from tomorrow," Mukaitsubo told AFP by telephone, criticising the government's "unclear" sampling methods.

"I don't know any more about my future," said Mukaitsubo, who takes milk from several local producers.

Yukihiro Ebisawa, an official at Japan Agricultural Cooperatives in Ibaraki prefecture, said they had received an order to tell spinach producers not to harvest or ship any more produce.

"We are worried... I hope the situation will calm down as soon as possible," Ebisawa told AFP.

On Thursday, Japan instructed local authorities to start screening food for radioactivity following a series of accidents at the plant 250 kilometres northeast of Tokyo.

It is the first time Japan has set legal radiation limits on domestically produced foodstuffs.

The guidelines vary depending on the product and type of radioactive substances, and were set in consideration of internationally accepted levels and average intake in the Japanese diet.

Abnormal levels of radioactive iodine were found in the water supply in Tokyo as well as the central prefectures of Gunma, Tochigi, Saitama, Chiba and Niigata, according to the science ministry official.

The March 11 quake and tsunami knocked out the reactor cooling systems at the nuclear complex, which led to a string of explosions and fires.

Radioactive substances have since leaked into the air and workers are now battling to restore power to the plant and get the cooling systems running.

Several Asian nations have said they will screen food imported from Japan for radiation, while the European Union has called for similar checks.

Japanese web users were quick to react to the announcements on popular micro-blogging service Twitter -- and their words for the government and Prime Minister Naoto Kan were anything but kind.

"What the prime minister can do is to go out in the field and eat this spinach and milk, this news will likely spark harmful rumours," said one with the username sakuya_ntg.

"This spinach and milk problem, I can't make head nor tail of it because there is no information on the sampling... or whether these two are the only positive results after lots of tests," said another, tweetingMiki.

"I am waiting for details."

Share This Article With Planet Earth DiggDigg RedditReddit
YahooMyWebYahooMyWeb GoogleGoogle FacebookFacebook

Related Links
Space Technology News - Applications and Research

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

Indonesia screens Japan travellers for radiation
Jakarta (AFP) March 19, 2011
Indonesia gave a preliminary all-clear Saturday after radiation-screening passengers arriving at Jakarta airport from Japan, which is battling to prevent leaks at a stricken nuclear power plant. "The nuclear energy regulatory agency, with the airport's management, started to carry out screenings on Tuesday," Soekarno Hatta international airport official Frans Yoseph told AFP. "Up until n ... read more

Japan again detects abnormal radiation in food

Radioactive traces found in Japan tap water

Pounding rain fuels radiation fears in Japan

Swiss embassy leaves Tokyo for Osaka amid nuclear fears

Advanced Emulation Accelerates Deployment Of Military Network Technologies

Tactical Communications Group Completes Deployment Of Ground Support Systems

Raytheon Announces Next Generation of ACU Interoperable Communications

InterSKY 4M Provides BLOS Comms For C4I Military Systems

LockMary To Launch DigitalGlobe WorldView-3 Earth Imaging Satellite

ORBCOMM And SpaceX Set Plans To Launch Satellites On Next Falcon 9

Arianespace's Success Is Built On Transparency

Arianespace To launch Argentina's Arsat-2 Satellite

N. Korea rejects Seoul's plea to stop jamming signals

Rayonier's GIS Strengthens Asset Management Capability

Space Team Improves GPS Capability For Warfighters

SSTL's European GNSS Payload Passes Design Review

NVision Scanner Helps Get Aircraft Accessories To Fit Right First Time

IATA sees sharp slowdown in Japan air traffic

Rolls-Royce forecasts helicopter boom

Flights to Japan cut as foreigners scramble to leave

Pruned' Microchips Are Faster, Smaller, More Energy-Efficient

Silicon Spin Transistors Heat Up And Spins Last Longer

3D Printing Method Advances Electrically Small Antenna Design

Taiwan's UMC to triple stake China chip maker

France fines Google 100,000 euros over Street View

NASA Satellites Show Towering Thunderstorms

NASA Satellite Sees Area Affected By Japan Tsunami

National Flooding Exercise Hones Use Of Satellites To Improve Disaster Mitigation

EPA proposes 1st mercury emissions limits

Russian police search office of outspoken activist

China cleaning up 'jeans capital'

Environmental Impact Of Animal Waste

The content herein, unless otherwise known to be public domain, are Copyright 1995-2010 - SpaceDaily. AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement