70 000 must evacuate around Fukushima

News24

Paris - Seventy thousand people living beyond the 20km no-go zone around Fukushima should be evacuated because of radioactivity deposited by the crippled nuclear plant, a watchdog said.

Updating its assessment of the March 11 disaster, France's Institute for Radiological Protection and Nuclear Safety (IRSN) highlighted an area northwest of the plant that lies beyond the 20km zone whose inhabitants have already been evacuated.

Radioactivity levels in this area range from several hundred becquerels per square metre to thousands or even several million bequerels per square metre, the IRSN report, issued late on Monday, said.

Around 70 000 people, including 9 500 children aged up to 14, live in the area, "the most contaminated territory outside the evacuation zone", the agency said.

"These are people who are still to be evacuated, in addition to those who were evacuated during the emergency phase in March," Didier Champion, its environment director, told AFP.

Staying in this area means the inhabitants would be exposed to radiation of more than 10 millisieverts (mSv)in the year following the disaster, according to the IRSN.

Taking precautions

This level is used in French safety guidelines for protecting civilian populations after a nuclear accident. In France, 10 mSv is three times the normal background radiation from natural sources.

"Ten mSV is not a dangerous dose in and of itself, it's more a precautionary dose," said Champion, noting however that this figure that does not include any additional doses from contaminated food or water.

The 10 mSV derives from a calculation of exposure to at least 600 000 becquerels per square metre, emitted by caesium 137 and 134, which are long-lasting radioactive elements.

Of the 70 000 people in the zone identified in the IRSN report, more than 26 000 could be exposed to doses of more than 16mSv in the first year after the disaster.

On May 15, Japan began to evacuate 4 000 residents of the village of Iidate-mura and 1 100 people in the town of Kawamata-cho, 30km from the plant. The two locations had consistently received high amounts of radioactive dust due to wind patterns.

The IRSN report is based on data for radioactivity reported by the Japanese authorities and from US over-flights of the zone.

Emerging ocean radiation problems may affect Pacific salmon

Design Community

There may be an emerging issue around testing for radiation in wild
Pacific salmon, one of the few relatively-healthy and sustainable fish
stocks remaining around the planet.

+ Local federal officials, according to AP coverage, are either
saying it's certainly not needed (FDA), or not commenting (NOAA):

Alaska, federal health officials say North Pacific fish not contaminated by Japan radiation - AP, 2011.0417
http://www.newser.com/article/d9mlogm02/alaska-federal-health-officials-say-north-pacific-fish-not-contaminated-by-japan-radiation.html

+ We know that Pacific salmon that spawn in North America range far
and wide in the open ocean, including as far as Japan and Russia and beyond:

Where do salmon go in the ocean? - NOAA
http://www.nefsc.noaa.gov/faq/fishfaq2d.html

BC Salmon Migration Patterns
http://www.canfisco.com/wildsalmon/salmon_migration.asp?pattern=summary

"In spring (May) chinook salmon were distributed south of the Aleutians
to 42°N latitude in the central North Pacific and to 40°N close to Japan..."
Ocean Distribution and Migration Patterns of Yukon River Chinook Salmon (2001)
http://www.fish.washington.edu/research/Publications/pdfs/0109.pdf

+ We know that ocean currents salmon are likely to follow
a) bring some portion of Pacific salmon toward Japan, and
b) are likely to carry a plume of radioactive material, along with
returning salmon, eastward into the Pacific from the coast of Japan:

Japan Radiation Release, Ocean Currents - Accuuweather, 2011.0406
http://www.accuweather.com/blogs/news/story/47990/japan-radiation-release-ocean-1.asp?partner=accuweather


Map of Pacific Ocean currents... 

+ We know that the releases of radioactive material into (and onto)
the ocean from the Fukushima Daiichi nuclear power plant are significant
and unprecedented.

How can a safety agency like the FDA know a-priori that the impacts
of an unprecedented event don't even need to be measured?

Radiation release will hit marine life - Nature, 2011.0412
http://www.nature.com/news/2011/110412/full/472145a.html

+ We know that radioactive isotopes can be concentrated
tremendously as they move up the food chain to a high-level predator
like the salmon.

Sounds like systematic monitoring of radiation levels in Pacific
salmon is really good idea. Systematic monitoring should start
promptly at least at a basic level to establish a solid baseline of data.

Thomas Hinton, deputy director of the IRSN Laboratory of Radioecology,
Ecotoxicology and Environmental Modelling in Cadarache, France, says
"The impacts are best addressed through an international long-term assessment."

I doubt there's any immediate risk from salmon already canned, or caught fresh on the Pacific coast of North America, because of the time lag in fish and currents crossing the ocean.

But once that time lag gets used up - and the Fukushima nuclear disaster is already five weeks old - then we'd better be ready with scientifically-sound monitoring already in place!

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Thanks to David Owen for assisting with research for this posting.