Japanese researchers have found high concentrations of accumulated dioxin in whale and dolphin meat sold in Japan, according to a report submitted to an international whaling meeting that opened Monday in Adelaide, Australia.
The report submitted to the Scientific Committee of the International Whaling Commission says that researchers headed by Koichi Haraguchi, associate professor at Daiichi University, College of Pharmaceutical Sciences in Fukuoka, detected dioxin levels up to 172 times the tolerable daily intake in marketed whale and dolphin meat.
Haraguchi’s team examined levels of dioxin as well as dibenzofuran and coplanar polychlorinated biphenyl, which have a toxicity similar to that of dioxin, in 38 types of whale and dolphin meat that were sold in Japan last year and earlier this year.
The highest concentration of dioxin was detected in the fat of dolphins, recording a maximum of 691 picograms per gram when the amount was converted into the most toxic dioxin, and 232 picograms on average, according to the report. A picogram is one-trillionth of a gram.
The second-highest concentration was found in the fat of minke whales in the North Pacific, at a maximum of 127 picograms. Minke whales in the Antarctic Ocean were relatively less contaminated with dioxin, with their fat containing a maximum of 8.4 picograms of the toxic substance and their lean meat holding 2.5 picograms.
When a person weighing 50 kg eats 50 grams of dolphin fat polluted with dioxin, the amount of carcinogen consumed would exceed the government-set TDI by 58 times on average and 172 times at most, the report says.
The fat of minke whales in the North Pacific contained dioxin averaging 14 times above the TDI and a maximum 32 times the standard. Dioxin levels higher than the TDI were detected in 28 samples of whale and dolphin meat, the researchers said.
The TDI is set at 4 picograms per kilogram of a person’s weight.
Haraguchi’s team also detected high concentrations of mercury in the meat of dolphins and whales already on the market and warned consumers of possible adverse health effects.
The researchers will release detailed data on their findings at an international conference on dioxin to be held in California in August.