B Investigation of the cause of Minamata disease
2. Results of the Study done by Kumamoto University Study Group

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.