Dr. Ito, the Head of the Minamata Public Health Center, with Dr. Takeuchi
succeeded to produce the intoxicated cats fed with fish and shellfish from
Minamata Bay in 1957.
Drs. Takeuchi, Tokuomi and Kitamura of Kumamoto University determined the
cause of Minamata disease was organic mercury in fish and shellfish from
the bay, and reported it on July 22, 1959.
They met objections that methylmercury could not be in the bay because
inorganic mercury, not organic mercury, was used at the suspected factory.
But Dr. Uchida detected methylmercury in shellfish living in Minamata Bay
in Nov. 1961. Dr. Irukayama extracted methylmercury compound from the waste
catalyst taken at the acetaldehyde production plant in Aug. 1962.