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 In 1956, it was confirmed for the first time that a disease of unknown cause was affecting people. Because the cause was unknown, doctors did not know what treatment to use at the hospitals. The patients were sterilized or isolated because it was mistaken for a contagious disease. As a result, the patients and their families experience discrimination throughout their lives. As the cause, theories of heavy-metal poisoning, organic mercury poisoning, pyrotechnic products and amine poisoning, etc. were released in addition to theories of rare diseases and infectious disease. In 1959, the Minamata food poisoning special committee, Food Sanitation Investigation Council, Ministry of Health and Welfare submitted a report to the Minister of Health and Welfare stating that "the main cause of Minamata disease was a certain type of organic mercurial compound in fish and shellfish around Minamata Bay." Later, the theory of organic mercury was researched, and in 1963 a research group from Kumamoto University released its findings that organic mercury was detected from factory discharged water. In 1968, Minamata disease was finally recognized by the government as a pollution disease caused by methylmercury discharged from the Chisso Minamata Factory. |
