The city was even dubbed Chissos "castle town," in reference to the capital cities of feudal lords who ruled Japan during the Edo period.The Chisso factory first started acetaldehyde production in 1932, with 210 tons that year. In 1951, production had jumped to 6,000 tons and eventually peaked at 45,245 tons in 1960. The factorys output historically amounted to between a quarter and a third of Japans total acetaldehyde production. The chemical reaction used to produce the acetaldehyde employed mercury sulfate as a catalyst. Starting in August 1951, the co-catalyst was changed from manganese dioxide to ferric sulfide. A side reaction of this catalytic cycle led to the production of a small amount (about 5% of the outflow) of the organic mercury compound methylmercury. As a result of the catalyst change, this highly toxic compound was released into Minamata Bay regularly between 1951 and 1968, when this production method was finally discontinued. 1956–1959
On 21 April 1956, a five-year-old girl was examined at Chissos factory hospital in Minamata. The physicians were puzzled by her symptoms: difficulty walking, difficulty speaking, and convulsions. Two days later, her younger sister also began to exhibit the same symptoms and she, too, was hospitalised. The girls mother informed doctors that her neighbours daughter was also experiencing similar problems. After a house-to-house investigation, eight further patients were discovered and hospitalised.
Instead, the affected were ostracised from their community due to ignorance about the disease, as people were afraid that it was contagious. The people directly impacted by the pollution of Minamata Bay were not originally allowed to participate in actions that would affect their future. Disease victims, fishing families, and company employees were excluded from the debate. Progress occurred when Minamata victims were finally allowed to come to a meeting to discuss the issue. As a result, postwar Japan took a small step toward democracy. Through the evolution of public sentiments, the victims and environmental protesters were able to acquire standing and proceed more effectively in their cause. The involvement of the press also aided the process of democratization because it caused more people to become aware of the facts of Minamata disease and the pollution that caused it. However, although the environmental protests did result in Japan becoming more democratized, it did not completely rid Japan of the system that first suppressed the fishermen and individuals with Minamata disease. Popular culture
Toshiko Akiyoshi, touched by the plight of the fishing village, wrote a jazz suite, "Minamata", that was to be the central piece of the Toshiko Akiyoshi-Lew Tabackin Big Bands 1976 album on RCA, Insights. The piece was constructed in three parts, to musically reflect the tragedy – "Peaceful Village", "Prosperity & Consequence", and "Epilogue". Akiyoshi used Japanese vocalists to sing the Japanese lyrics of a tone poem that were part of the composition.