23 April 2003
whale meat exceeds mercury density safety limits
levels in whales caught in Japan's coastal waters increase the further
south the creatures are caught, with one specimen from Okinawa's
Nago registering a mercury density more than 57 times the nation's
provisional safety limit, according to a group of experts.
member Tetsuya Endo, a lecturer at the Health Sciences University
of Hokkaido, said that mercury dissolved in seawater may have accumulated
in fish and other whale prey along the Black Current, which flows
north toward Japan's Pacific coast from east of the Philippines.
mercury may stem from industrial pollution in Japan and Southeast
Asia, as well as from natural sources such as undersea volcanic
activity, Endo said.
group said it will present its findings at a May meeting of the
Food Hygiene Society of Japan in Tokyo. Efforts to gain a comprehensive
understanding of the problem are only in their infancy as there
is no comprehensive data on mercury density in the sea.
researchers analyzed mercury density in 83 slices of red meat obtained
from different kinds of whales, bought from six regions stretching
from Abashiri in Hokkaido to Nago between 2000 and 2002.
slice exceeded Japan's provisional limit on the maximum density
of mercury, which stands at 0.4 parts per million. In Nago, researchers
identified an average mercury density of 11.6 ppm.
was followed by Taiji in Wakayama Prefecture, at 9.8 ppm.
the time the group worked its way up to Abashiri, which faces the
Sea of Okhotsk, the average mercury density had fallen to 0.8 ppm,
still double the acceptable limit.
slice of whale meat in Nago had a mercury density of 23.1 ppm, the
highest level recorded by the group.
researchers also looked specifically into methyl mercury, which
damages the nervous system and was responsible for causing Minamata
disease in the 1950s and 1960s. The highest level was identified
in whale meat from Taiji, at 10.6 ppm, more than 35 times the methyl
mercury limit of 0.3 ppm.