Q3: What a company was the source of the pollution that caused Minamata disease?

A3: Chisso Corp. (called Shin-Nippon Chisso Hiryo K.K. at that time) was responsible.

Commentary:
Around 1955, Chisso Corp. produced the majority of the acetaldehyde used in Japan at its factory in Minamata.
Acetaldehyde was largely used as a raw material for manufacturing products such as plastics in those days.
In the manufacturing process, methylmercury was formed and contaminated wastewater, a large amount of which was discharged into the sea.
In addition, Niigata Minamata disease was caused by methylmercury discharged from Kanose factory of Showa Denko K.K. into the Agano River.