Bluefin tuna contaminated with radioactivity from Japan’s crippled Fukushima nuclear power plant have traveled 6,000 miles to US shores.
A study in the journal Proceedings of the National Academy of Sciences indicates the tuna showed elevated levels of radioactive cesium 10 times higher than the amount measured in tuna off the California coast in previous years.
“That’s a big ocean. To swim across it and still retain these radionuclides is pretty amazing,”lead researcher Nicholas Fisher said.
Pacific Bluefin tuna can grow to 10 feet and weigh more than 1,000 pounds. They spawn off the coast of Japan and then swim to California and Mexican waters.
Scientists told Reuters cesium-137 and cesium-134 were detected in 15 tuna caught near San Diego in August 2011, about four months after these chemicals were released into the water off Japan’s east coast.
Doctoral student Daniel Madigan, who studies the migration patterns of tuna at Stanford University’s Hopkins Marine Station, noted that the amount of radioactive material detected was far less than the Japanese safety limit.
But according to the group Physicians for Social Responsibility, there is no safe level of radionuclide exposure, whether from food, water or other sources.
Madigan claims there were probably much higher levels of cesium 134 present in Bluefin tuna off Japan soon after the accident, as much as 40 to 50 percent higher than normal.
“Cesium 134 decays quickly, with a half-life of two years. Bluefin tuna excrete it on a daily basis and it also gets diluted in their bodies as they grow.”
When Madigan and Fisher tested for the isotopes in Bluefin tuna that migrated to California before the Fukushima disaster and yellowfin tuna that are native to California waters, the radioactivity wasn’t present, which indicated that it came from Fukushima, Fisher said.
The amount of Cesium 134 and 137 detected in the fish “didn’t come close to exceeding safety limits,”Madigan said, noting that what was in the fish, per gram, is lower than the amount of naturally occurring radioactive potassium found per gram in a banana.
“I wouldn’t tell anyone what’s safe to eat or what’s not safe to eat,” Madigan said in a telephone interview with Reuters.
“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 Huffington Post suggests Bluefin tuna radiation concerns may be a moot point, because according to seafood distributors interviewed by the San Francisco Chronicle, Bluefin tuna eaten by Americans is usually farmed.
No Safe Level of Radiation
Please note how most every single main stream media outlet constantly downplays concerns over radioactive contamination.
Reuters points out that unlike some other compounds, radioactive cesium does not quickly sink to the sea bottom but remains dispersed in the water column, from the surface to the ocean floor.
“Fish can swim right through it, ingesting it through their gills, by taking in seawater or by eating organisms that have already taken it in.”
A San Diego news report [via Washington’s Blog] warns that the real test of how radioactivity affects tuna populations comes this summer when researchers planned to repeat the study with a larger number of samples.
“Bluefin tuna that journeyed last year were exposed to radiation for about a month. The upcoming travelers have been swimming in radioactive waters for a longer period. How this will affect concentrations of contamination remains to be seen.”
Nicholas Fisher told the BBC that the fish arriving now, and in the coming months to California waters may be carrying considerably more radioactivity and if so they may possibly be a public health hazard.
As Washington’s blog points out, Japanese and U.S. officials are pretending that the amount of radiation found in the bluefin is safe.
“But the overwhelming scientific consensus is that there is no safe level of radiation — and radiation consumed and taken into the body is much more dangerous than background radiation.”