Elevated levels of dioxin and polychlorinated biphenyls were found in the livers of squid, cod and bottom-dwelling sharks off the coast of Japan, according to interim results from an Environment Agency survey released Friday.
Sharks from Tokyo Bay, squid liver from the East China Sea and cod liver from the Sea of Japan showed relatively high concentrations of PCBs, with averages of 3,288, 109 and 390 parts per billion.
As for dioxin pollution:
* Sharks from Tokyo Bay were more than double those caught elsewhere, with an average of 183 picograms per gram of liver.
* Cod from the Sea of Japan logged 92 picograms of dioxin per gram, nearly 41/2 times than in cod caught off the coast of Sendai, Miyagi Prefecture.
* Squid from the East China Sea logged 19 picograms of dioxin almost double the amount in squid taken from the Black Current area off the Kanto region.
Officials were at a loss to explain the varied levels but said they do not pose a health threat to people.
The survey is being carried out to shed light on pollution levels in sediment, water and, for the first time, sea life.
The survey is to conclude in 2003, at which point the agency will consider what measures should be taken based on the results, officials said.