Transcript 柴歆烨--汞和水俣病
Our topic: MINAMATA DISEASE & MERCURY 水俣病和汞 柴歆烨 吕洲 秦嵩 蒋敏娜 Silver Aven Wolf Minmin 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 dead fish 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. The Cause of Minamata Disease For production purposes, the company made use of large amounts of mercury compounds as reaction catalysts. The increased volume of production wastes was discharged into Minamata Bay without any treatment. 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 Hg 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 Mechanism What’s worse, mercury can Cross blood-brain barrier as well as placenta barrier, so parents need information in order to protect not only their own health but also the health of their unborn babies. Treatment Major reductions bans in paint and pesticides, phaseouts in batteries , and reductions in industrial uses. Continued effective control of mercury emissions may require a mix of strategies including pollution prevention, materials separation, and conventional regulatory approaches. Mercury Investigations Developing Bacteria that Degrade Contaminants 环保小贴示 选用漂白、祛斑化妆品要慎之又慎。要选好 的品牌，看清有无特殊化妆品批准文号。 购买荧光灯时，买弯不买直，买细不买粗。 就是说，首选节能灯；若买直管型的，就买 灯管细的。若能买采用汞丸、汞齐技术的更 好。废弃时，千万不要摔破。 补牙时，患者可要求尽量避免使用银汞 齐材料，或将多余的银汞合金收集在盛 有饱和盐水或甘油的器皿内。医护人员 应加强诊疗室通风换气，储汞瓶要严密 封闭。 控制吃鱼总量。吃年轻的鱼，少吃吃鱼 的鱼和鱼的内脏、鱼头、鱼皮。注意搭 配富硒富硫的食品。