[Marxism] Glow in the dark sushi

Louis Proyect lnp3 at panix.com
Tue May 29 07:07:33 MDT 2012


Tuna contaminated with Fukushima radiation found in California

Scientists amazed that bluefins swimming in Pacific five months 
after Japanese disaster contained tiny amounts of caesium

by Justin McCurry in Tokyo and agencies

Bluefin tuna contaminated with radiation believed to be from 
Fukushima Daiichi turned up off the coast of California just five 
months after the Japanese nuclear plant suffered meltdown last 
March, US scientists said.

Tiny amounts of caesium-137 and caesium-134 were detected in 15 
bluefin caught near San Diego in August last year, according to a 
study published on Monday in the Proceedings of the National 
Academy of Sciences journal.

The levels were 10 times higher than those found in tuna in the 
same area in previous years, but still well below those that the 
Japanese and US governments consider a risk to health. Japan 
recently introduced a new safety limit of 100 becquerels per 
kilogram in food.

The timing of the discovery suggests that the fish, a prized but 
dangerously overfished delicacy in Japan, had carried the 
radioactive materials across the Pacific ocean faster than those 
conveyed by wind or water.

The researchers, led by Daniel Madigan at Stanford University, 
said they had found evidence that the fish had been contaminated 
at "modestly elevated" levels with caesium. The chemical was 
released into the ocean in the wake of the accident at Fukushima 
Daiichi on 11 March 2011.

Madigan told Reuters: "I wouldn't tell anyone what's safe to eat 
or what's not safe to eat. It's become clear that some people feel 
that any amount of radioactivity, in their minds, is bad and 
they'd like to avoid it. But compared to what's there naturally 
... and what's established as safety limits, it's not a large 
amount at all."

The fish are thought to have been exposed to radiation for about a 
month before beginning their journey east across the Pacific. They 
were found to contain 4 becquerels per kilogram of caesium-134 and 
6.3 becquerels per kilogram of caesium-137, the report said. A 
2008 study of fish in the area found no evidence of caesium-134, 
which is produced only by nuclear power plants and weapons, and 
caesium-134 only at levels that naturally occur in the environment.

The results "are unequivocal. Fukushima was the source", said Ken 
Buesseler of the Woods Hole Oceanographic Institution, who played 
no part in the research.

Japan's chief cabinet secretary, Osamu Fujimura, conceded that the 
findings suggested the monitoring of radiation levels in fish 
outside Japanese waters may have to be stepped up.

The spawning and migratory patterns of bluefin tuna indicate that 
the issue of contaminated fish will be confined to Pacific coastlines.

Bluefin spawn only in the western Pacific, off the coasts of Japan 
and the Philippines. Some juvenile or adolescent fish migrate east 
to the coast of California coast and remain there to fatten up.

Scientists say they do not believe contamination will linger in 
large fish capable of swimming farther afield, as they are able to 
metabolise and excrete radioactive substances.

The fish examined in the US study weighed an average of 15 pounds. 
They had shed some of the radionuclides during their journey but 
had been unable to flush them out altogether.

"We were frankly kind of startled," said Nicholas Fisher, an 
expert at Stony Brook University in New York who took part in the 
study. "That's a big ocean. To swim across it and still retain 
these radionuclides is pretty amazing."

The operator of the Fukushima Daiichi plant, Tokyo Electric Power, 
estimates that 18,000 terabecquerels of radioactive materials 
flowed into the Pacific after the accident, either in the form of 
fallout, or through mixing with water that leaked from the 
facility. A terabecquerel is equal to 1tn becquerels.

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