A Outline of Minamata Disease
2. Orientation

Minamata disease is due to a typical Industrial pollution incident caused by pollutant generated in industrial activities. The disease was officially recognized on May 1, 1956. The characteristics of Minamata disease are summarized as follows (relevant exhibitions).

1. The causative substance was methylmercury.(Link1,Link2)

2. The wastewater containing methylmercury changed from inorganic form in the production process was discharged from the factory into Minamata bay and polluted sea and river. (Process of Acetaldehyde production)(The companies caused Minamata disease were Chisso Corp. in Yatsushiro Sea coast (Kumamoto and Kagoshima Prefectures) and Showa Denko Co., Ltd. in Agano River basin (Niigata Prefecture)

3. Fish and shellfish as well as sea environment were polluted by the wastewater (Link) → (Bioaccumulation)

4. Legally certificated patients are 2,265 in Yatsushiro Sea coast and 690 in Agano River basin as of the end of December 2000.

5. Minamata disease was occurred during economic rapid growth (in 1950’s and 1960’s) in Japan. It is generally considered that social and economical condition at that time was one of the factors causing Minamata Disease. (Link) → (Social background of Minamata disease)