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Home > Outline of Japan's Industrial Pollution Abatement > Approaches to Water Pollution Control (Case Study-2) Minamata City, Kumamoto Prefecture > (3) Clinical Picture of Minamata Disease

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Update:April 1, 2010

(3) Clinical Picture of Minamata Disease

1.Establishment of Chisso Co., Ltd. and Outbreak of Minamata Disease

Minamata Disease is a toxic symptom accompanied by the problems in the central nervous system caused by oral intake of food containing methylmercury compounds (CH3HgCl). Minamata Disease, as the established theory suggested, is characterized by problems in the nervous systems unlike inorganicmercury poisoning which induces sickness in the livers.
From a clinical point or view, a variety of symptoms have been reported. Typical symptoms are disturbance of sensation of all four limbs, speech impediment, cerebellar ataxia (failure of muscular coordination), concentric constriction of visual fields (contraction of visual fields), central eyeball motor disturbance (disturbance in smooth eyeball movement), central hearing loss, and central disturbance (imbalance of the body).
Another report says that intake of food containing methylmercury compounds during pregnancy may induce cerebral infantile paralysis, which is called Fetal Minamata Disease.