Minamata Bay Japan

This incident, in 1965, led to almost 50 deaths and to 100 seriously ill people. They displayed symptoms of mercury poisoning and the problem was traced to mercury which had been discharged into the bay by a chemical company. There it was converted into the very toxic dimethyl mercury by microorganisms at the bottom of the sea. This substance concentrated in fish which were subsequently eaten by the victims. 

Incidents such as this led to a major tightening up of pollution laws in Japan and nowadays up to 50% of the capital cost of a new plant can be earmarked for pollution control equipment. 

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Methylmercury in the marine environment may originate from industrial discharges or be synthesised by natural methylation processes. Fish do not themselves methylate inorganic mercury [62,64], but can accumulate methyl mercury from sea water [63]. Methylmercury has been detected in sea water only from Minamata Bay, Japan, an area with a history of gross mercury pollution from industrial discharge. It has been found in some sediments but at very low concentrations, mainly from areas of known mercury pollution. It represents usually less than 1% of the total mercury in the sediment, and frequently less than 0.1% [65-67]. Microorganisms within the sediments are considered to be responsible for the methylation [65,68], and it has been suggested that methylmercury may be released by the sediments to the sea water, either in... 

Mercury concentrations in selected biological and nonbiological materials collected from Minamata Bay, Japan, and environs... 

Table 5.4 Mercury Concentrations in Selected Biological and Nonbiological Materials Collected From Minamata Bay, Japan and Environs (Concentrations are in mg Hg/kg [ppm] fresh weight [FW], or dry weight [DW].)...

Between 1956 and 1960 severe accidents related to Me-Hg, the health consequences of which were afterwards grouped under the name of Minamata disease, occurred in Japan following long-term consumption of contaminated fish and fish products. A large amount of Hg-polluted effluents (from 200 to 600 tons) reached Minamata Bay, Japan, where they accumulated not only in the bottom sediment, but also in fish and shellfish. The consumption of such foods resulted in a mass outbreak of Me-Hg poisoning [9]. 

The greatest tragedy of all involving mercury unfolded in Minamata Bay, Japan, between 1953 and 1970. Industrial effluents containing mercury compounds were discharged untreated into the bay, and Hg accumulated in fish, which were then caught and eaten by the inhabitants of that coast. Those people soon began to... 

Methylmercury causes neurotoxicological effects in cats and dogs. Cats ingesting contaminated fish around Minamata Bay, Japan, died after paroxysmal fits (i.e., cat-dancing disease ). Mink are particularly sensitive to the toxicity of methylmercury. Methylmercury is also fetotoxic and teratogenic in laboratory mammals. 

Minamata disease was first discovered in 1956 around Minamata Bay, Japan. A similar epidemic occurred in 1965 along the Agano river, Japan. Minamata disease is methyl mercury poisoning that occurred in humans who ingested fish contaminated with methylmercury discharged in waste water from a chemical plant. Methylmercury is also teratogenic (Ui 1992, Harada 1995, Eto 1997, Schardein 2000 see also Part III, Chapter 17). 

The so-called Minamata disease" is a form of poisoning that developed in the coastal area of Minamata Bay, Japan, in 1956. Industrial waste waters, contaminated primarily with inorganic mercury salts, caused this mass catastrophe. In the water, the mercury was methylated by bacteria to... 

Up to 600 tons of methylmercury were discharged into Minamata Bay, Japan, between 1932 and 1971 from acetaldehyde manufacturing plants. Human fatalities were documented beginning in 1953 from consumption of methylmercury-contaminated fish and shellfish from the Bay. By 1993, about 2000 victims of Minamata Disease were identified including more than 100 deaths and 59 congenital birth defects from a total regional population of about 200,000 however, at least 10,000... 

Minamata Bay (Japan) leading to resulting in increased solar... 

Biological concentration is a problem that occurs when industries release heavy metal ions into the waterways. As metal ions move through the ecosystem, they become more and more concentrated. (The same thing happens with radioisotopes — see Chapter 5 for details.) The ions may be released at a very low concentration level, but by the time they move up the food chain to us, the concentration may be at the toxic level. This situation happened in Minamata Bay, Japan. An industry was dumping mercury metal into the bay. As the metal moved through the ecosystem, it was eventually converted to the extremely toxic methylmercury compound. People died as a result of the toxins, and others became permanently affected. 

Detection of traces of toxic chemicals in drinking water supplies, in polar ice caps, groimdwater sources and episodes such as those in Minamata Bay, Japan and Love Canal, USA have focused the attention of the public worldwide on the risks posed by the inappropriate disposal of hazardous waste and accidental release of toxic chemicals into the environment. In India the concern... 

Wang et al. (1989) are found in 90% of the mer determinants of bacilli isolated from mercury-polluted sediment from Minamata Bay, Japan (K. Nakamura and S. Silver, submitted). 

The first incident in the modern era to bring mercury and its hazards to the public eye occurred at Minamata Bay, Japan, in 1953. Here many fishermen and their families were stricken with mercury poisoning when they ate fish and shellfish that contained high amounts of mercury, ultimately traced to the effluent of a nearby poly(vinylchloride) factory. Mercury in fish, particularly those such as tuna, marlin, and swordfish at the top of aquatic food chains, soon became a newsworthy... 

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