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)