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Introduction: MINAMATA DISEASE 水俣病 What we now call “Minamata disease” was first observed in communities near Minamata Bay in Southwestern Japan. The Fact of Minamata Disease Levels of methylmercury chloride reached 50 ppm in fish and 85 ppm in shellfish obtained from the contaminated areas. One hundred and twenty one persons were poisoned, 46 fatally, from eating the contaminated fish. Dogs, cats, pigs, rats, and birds living around the bay developed classical clinical signs and many died. The symptom of Minamata Disease In most cases, first without any apparent signs. numbness of the limbs and the area around the mouth,sensory disturbance, difficulty with hand movements. lack of coordination, weakness and tremor, slowed and slurred speech, ataxic gait, disturbances of vision and hearing. Became aggravated and led to general paralysis, deformity of the limbs, difficulty in swallowing, convulsions, and death. It is Mercury By 1959 it had been demonstrated that the minamata disease was caused by ingestion of fish contaminated by mercury discharged from a chemical manufacturer plant. About Environmental Mercury Mercury is a silvery, liquid metal at room temperature. It is sometimes referred to as one of the heavy metals.“ Like water, mercury can evaporate and become airborne. Because it is an element, mercury does not break down into less toxic substances. Bacteria and chemical reactions in lakes and wetlands change mercury into a much more toxic form known as methylmercury. Mercury enters the environment from: A naturally occurring element Natural sources : volcanoes and the weathering of rocks Our intentional uses of mercury Our unintentional releases of mercury :burning fossil fuels and smelting metals A by-product of gold and zinc mining Power plants are responsible for 34% of the total mercury emitted by all known sources. More than 99% of that mercury comes from coal-fired power plants. Pollution Mech