Fish from waters off Fukushima have not been delivered to the market. (Photo: T. Engoe)
Fish caught off Fukushima exceeds cesium legal limit
Thursday, August 23, 2012, 01:30 (GMT + 9)
Fish containing 258 times the legal limit of radioactive cesium have been caught in waters off Fukushima, according to Fukushima No 1 nuclear power plant operator Tokyo Electric Power Co (TEPCO).
Two rock trout caught about 20 km (12 mi) to the north of the plant were found to contain 25,800 becquerels per kg of cesium -- the highest amount detected in surveys done since last year's nuclear catastrophe.
Consuming 200 g of fish containing this amount of cesium would amount to an internal radiation exposure of 0.08 millisievert for a human. The annual safety limit for radiation exposure from food products is 1 millisievert.
It was noted that fishers are not currently fishing off Fukushima, however, and no rock trout harvested from the area have been sold to the market, The Asahi Shimbu reports.
"The reading was way beyond the levels recorded before," Tetsu Nozaki, who heads the Fukushima Prefectural Federation of Fisheries Co-operative Associations, said. "It is worrying."
Officials were surprised by the findings, which had previously shown much lower levels of radiation in affected fish, RT reports.
The finding comes after the federation once more started fishing for some octopus and shellfish in waters off Soma, in the northern part of the prefecture, between June and early August of this year on a trial basis -- but only in areas more than 31 mi from the plant. Those fish were distributed to markets, including Tokyo, and sold to the public for consumption.
Japan’s government banned shipments of seafood caught off Fukushima since May 2011, except for two types of octopus and one type of shellfish that were shown to be within cesium safety levels, explained Noriyuki Mizobe, a group manager in the resources and environment research division of Japan’s Fisheries Agency.
Nozaki’s federation will formally request that TEPCO investigate why such high levels of contamination were detected in the rock trout, he stated.
"We operate on the assumption that no additional contaminated water was leaked into the sea from the plant," he continued.
TEPCO officials have said that there could be radioactive "hot spots" at the bottom of the sea where cesium is concentrated, and that rock trout were affected because they usually reside near the seabed. The company wants to study the cesium levels in the crabs and the shrimp eaten by rock trout as well as in the seabed soil to determine the exact cause of the high radiation.
In April 2011, a survey found 14,400 becquerels per kg for sand eel caught off the coast of the prefecture.
In March 2012, landlocked salmon in the Niidagawa river near Iitate, a village to the northwest of the plant, was found to be contaminated with 18,700 becquerels of cesium per kg.
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-Fukushima octopus sold in Tokyo once more
By Natalia Real