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What is the Minamata disease? When was the disease? Where was the disease?

The Minamata disease is a poisoning of organic mercury (sometimes known as the Chisso Minamata disease) it affects mainly the central nervous system. The compound identified as organic mercury (methyl mercury) has the formula H3C-Hg+x-. The disease was caused by the contamination of water therefore contaminating the fish and shellfish and consumed by humans. The source of the contamination was the release of methyl mercury in waste water from Chisso Corporation’s chemical Factory which continued from 1932 till 1968. In March 1958, British neurologist Douglas Mc Alphine was the first to suggest that the symptoms resembled those of organic mercury poisoning and he was right. Symptoms of the Minamata disease include ataxia, numbness in limbs, muscle weakness, damage of hearing, sight and speech. A larger exposure to the organic mercury would cause insanity, paralysis, coma and death. The first discovery of the Minamata disease was in Minamata city in Kumamoto prefecture, Japan in 1956.

The second outbreak of the Minamata disease was in Niigata Prefecture in 1965. The source of contamination was the release of methyl mercury in the Agano River from Showa Electrical Company’s chemical plant in Kanose village.

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