It was caused by the release f methylmercury in the industrial wastewater (point source pollution) from the Chisso Corporation''s chemical factory, which continued from 1932 to 1968. This highly toxic chemical bioaccumulated in shellfish and fish in Minamata Bay and the Shiranui Sea, which when eaten by the local populace resulted in mercury poisoning. While cat, dog, pig and human deaths continued over more than 30 years, the government and company did little to prevent the pollution.
As of March 2001 , 2,265 victims had been officially recognized (1,784 of whom had died) and over 10,000 had received financial compensation from Chisso. By 2004, Chisso Corporation had paid $86 million in compensation, and in the same year was ordered to clean up its contamination. Lawsuits and claims for compensation continue to this day. A second outbreak of Minamata disease occurred in Niigata Prefecture in 1965. Both the Four Big Pollution Diseases of Japan. ln this case study we are going to analyse the origin and some solutions to the problem.
ANALYSIS OF THE PROBLEM ORIGIN OF THE DISEASE :-The Chisso Corporation first opened a chemical factory in Minamata in 1908. Initially producing fertilizers, the factory followed the nationwide xpansion of Japan''s chemical industry, branching out into production of acetylene, acetaldehyde, acetic acid, vinyl chloride and octanol, among others. The Minamata factory became the most advanced in all Japan, both before and after World War II. The waste products resulting from the manufacture of these chemicals were released into Minamata Bay in the factory wastewater.
Inevitably, these pollutants had an environmental impact. Fisheries were damaged in terms of reduced catches and in response Chisso reached two separate compensation agreements with the fishery cooperative in 1926 and 1943. The ChissoMinamata actory first started acetaldehyde production in 1932, producing 210 tons that year. By 1951 production had Jumped to 6,000 tons per year: over 50% of Japan''s total output. The chemical reaction used to produce the acetaldehyde used mercury sulfate as a catalyst.
A side reaction of the catalytic cycle led to the production of a small amount of an organic mercury compound, namely methyl mercury. This highly toxic compound was released into Minamata Bay from the start of production in 1932 until 1968 when this production method was discontinued. On April 21, 1956, a five year-old girl was first affected by this disease. Doctors were unable to identify the diseaseTo investigate the epidemic, the city government and various medical practitioners formed the Strange Disease Countermeasures Committee at the end of May 1956.
Owing to the localized nature of the disease, it was suspected to be contagious and as a precaution patients were isolated and their homes disinfected. Unfortunately, this contributed to the stigmatisation and discrimination experienced by Minamata victims from the local community. During its investigations, the committee uncovered surprising anecdotal evidence of the strange behavior of cats nd other wildlife in the areas surrounding patients'' homes. From around 1950 onwards, cats had been seen to have convulsions, go mad and die.
Locals called it the "cat dancing disease", owing to their erratic movement. Crows had fallen from the sky, seaweed no longer grew on the sea bed and fish floated dead on the surface of the sea. As the extent of the outbreak was understood, the committee invited researchers from Kumamoto University to help in the research effort. The Kumamoto University Research Group was formed on August 24, 1956. Their research works resulted in the uncovering of more complete picture of the symptoms exhibited by loss of sensation and numbness in their hands and feet.
They became unable to grasp small objects or fasten buttons. They could not run or walk without stumbling, their voices changed in pitch and many patients complained of difficulties seeing, hearing and swallowing. In general, these symptoms deteriorated and were followed by severe convulsions, coma and eventual death. By October 1956, 40 patients had been discovered, 14 of whom had died: a mortality rate of 36. 7%. DETECTION OF THE CAUSE:-Reserchers found that the victims, often members of the same family, were clustered in fishing hamlets along the shore of Minamata Bay.
The staple food of victims was invariably fish and shellfish from Minamata Bay. As soon as the investigation identified a heavy metal as the causal substance, the wastewater from the Chisso plant was immediately suspected as the origin. The company''s own tests revealed that its wastewater contained many heavy metals in concentrations sufficiently high to bring about serious environmental degradation; these metals included lead, mercury, manganese, arsenic, selenium, thallium and copper.
Identifying which particular poison was responsible for the disease proved to be extremely difficult and time consuming. Thallium, selenium and a multiple contaminant theory were also proposed but it was not until March 1958, when visiting British neurologist Douglas McAlpine suggested that Minamata symptoms resembled those of organic mercury poisoning, that the focus of the investigation centered on mercury.
On November 12, 1959 the Ministry of Health and Welfare''s Minamata Food Poisoning Subcommittee published its results: "Minamata disease is a poisoning disease that affects mainly the central nervous system and is caused by the consumption of large quantities of fish and shellfish living in Minamata Bay and ts surroundings, the major causative agent being some sort of organic mercury compound. " During the investigation by researchers at Kumamoto University, the causal substance was identified as a heavy metal and it was widely presumed that the Chisso plant was the source of the contamination.
Chisso came under closer scrutiny and in order to deflect criticism the wastewater output route was changed. Chisso knew the environmental damage caused by its wastewater and was well aware that it was the prime suspect in the Minamata disease investigation. Despite this, from September 1958, instead of discharging its waste into HyakkenHarbour (the ocus of investigation and source of original contamination), it discharged wastewater directly into Minamata River.
The immediate effect was the death of fish at the mouth of the river, and from that point on new Minamata disease victims began to appear in other fishing villages up and down the coast of the Shiranui Sea, as the pollution spread over an even greater area. Chisso failed to co-operate with the investigation team from Kumamoto University. It withheld information on its industrial processes, leaving researchers to speculate what products the factory was producing and by what methods.
In July 1959, the Chisso factory''s hospital director, Hajime Hosokawa, established a laboratory in the research division of the plant to carry out his own experiments into Minamata disease. Food to which factory wastewater had been added was fed to healthy cats. Seventy-eight days into the experiment, cat 400 exhibited symptoms of Minamata disease and pathological examinations confirmed a diagnosis of organic mercury poisoning. The company did not reveal these significant to undermine Kumamoto University researcher''s organic mercury theory, Chisso and other parties with a vested interest in the factory remaining open (including the
Ministry of International Trade and Industry and the Japan Chemical Industry Association) funded research into alternative causes of the disease, other than its own waste. Polluting wastewater had damaged the fisheries around Minamata since the opening of the Chisso factory in 1908. The Minamata Fishing Cooperative had managed to win small payments of "sympathy money" from the company in 1926 and again in 1943, but after the outbreak of Minamata disease the fishing situation was becoming critical. Fishing catches had declined by 91% between the years 1953 and 1957. On
August 29, the fishing cooperative agreed to the mediation committee''s proposal, stating: "In order to end the anxiety of the citizens, we swallow our tears and accept". The company paid the cooperative JPY20 million (USD55,600) and set up a JPYI 5 million (USD41 ,700) fund to promote the recovery of fishing. Since the change of route of wastewater output in 1958, pollution had spread up and down the Shiranui Sea, damaging fisheries there too. Emboldened by the success of the small Minamata cooperative, the Kumamoto Prefectural Alliance of Fishing Cooperatives also decided to seek compensation from Chisso.
On October 17, 1,500 fishermen from the alliance descended on the factory to demand negotiations. When this produced no results, the alliance members took their campaign to Tokyo, securing an official visit to Minamata by members of the Japanese Diet. During the visit on November 2 alliance members forced their way into the factory and rioted, causing many injuries and JPYIO million (USD27,800) worth of damage. The violence was covered widely in the media, bringing the nation''s attention to the Minamata issue for the first time since the outbreak began.
Another mediation committee was set up, an agreement ammered out and signed on December 17. JPY25 million "sympathy money" was paid to the alliance and a JPY65 million fishing recovery fund established. In 1959, the victims of Minamata disease were in a much weaker position than the fishermen. The recently formed Minamata Disease Patients Families Mutual Aid Society was much more divided than the fishing cooperatives. Patients'' families were the victim of discrimination and ostracism from the local community.
Local people felt that the company was facing economic ruin. To some patients this ostracism by the community represented a greater fear than the disease itself. After beginning a sit-in at the factory gates in November 1959 the patients asked Kumamoto Prefecture Governor HirosakuTeramoto to include the patients'' request for compensation with the mediation that was ongoing with the prefectural fishing alliance. Chisso agreed and after a few weeks'' further negotiation, another "sympathy money" agreement was signed.
Patients who were certified by a Ministry of Health and Welfare committee would be compensated: adult patients received JPYIOO,OOO (USD278) per year; children JPY30,OOO (USD83) per year and families of dead patients would receive a one-off JPY320,OOO (USD889) payment. On October 21 the Ministry of International Trade and Industry ordered Chisso to switch back its wastewater drainage from the Minamata River to HyakkenHarbour and to speed up the installation of wastewater December 19, 1959. Testimony at a later Niigata Minamata disease trial proved that Chisso knew the Cyclator was completely ineffective: "... he purification tank was installed as a social solution and did nothing to remove organic mercury. "The years between the first set of "sympathy money" agreements in 1959 and the start of the first legal action to be taken against Chisso in 1969 are often called the "ten years of ilence". In fact, much activity on the part of the patients and fishermen took place during this period, but nothing had a significant impact on the actions of the company or the coverage of Minamata in the national media.
Despite the almost universal assumption to the contrary, the wastewater treatment facilities installed in December 1959 had no effect on the level of organic mercury being released into the Shiranui Sea. The pollution and the disease it caused continued to spread. Minamata disease broke out again:- In 1965, this time along the banks of the Agano River in Niigata Prefecture. The polluting factory employed a chemical process using a mercury catalyst very similar to that used by Chisso in Minamata.
As in Minamata, from the autumn of 1964 to the spring of 1965, cats living along the banks of the Agano River were seen going mad and dying. Before long, patients appeared with identical symptoms to patients living on the Shiranui Sea, and the outbreak was made public on June 12, 1965. Researchers from the Kumamoto University Research Group and Hajime Hosokawa (who had retired from Chisso in 1962) used their experience from Minamata and applied it to the Niigata outbreak.
In September 1966, a report was issued proving Showa Denko''s pollution to be the cause of this second Minamata disease. Slowly but surely the mood in Minamata, and Japan as a whole, shifted. Minamata patients found the public gradually becoming more receptive and sympathetic as the decade wore on. This culminated in the establishment in Minamata of the Citizens'' Council for Minamata Disease Countermeasures in 1968, which was to become the chief citizens'' support group to the Minamata patients.
A founding member of the citizens'' council was Michiko Ishimure, a local housewife nd poet who later that year published Pure Land, Poisoned Sea: Our Minamata Disease, a book of poetic essays that received national acclaim. THE MESAURES TAKEN BY GOVERNMENT Finally on September 26, 1968 — twelve years after the discovery of the disease (and four months after Chisso stopped production of acetaldehyde using its mercury catalyst) — the government issued an official conclusion as to the cause of Minamata disease.
The conclusion contained many factual errors: eating fish and shellfish from other areas of the Shiranui Sea, not Just Minamata Bay, could cause the disease; ating small amounts, as well as large amounts of contaminated fish over a long time also produced symptoms; the outbreak had not in fact "ended" in 1960 nor had mercury-removing wastewater facilities been installed in January 1960. Nevertheless, the government announcement brought a feeling of relief to many victims and their families.
Many felt vindicated in their long struggle to force Chisso to accept responsibility for causing the disease and expressed thanks that their plight had extent the victims should be compensated. STRUGGLE OF VCTIMS FOR COMBENSATlON:-ln light of the government announcement, the patients of the Mutual Aid Society decided to ask for a new compensation agreement with Chisso and submitted the demand on October 6. The company replied that it was unable to judge what would be fair compensation and asked the national government to set up a binding arbitration committee to decide.
This proposal split the members of the patients'' society, many of whom were extremely wary of entrusting their fate to a third party, as they had done in 1959 with unfortunate results. An arbitration committee was duly set up by the Ministry of Health and Welfare on April 25, but it took almost a year to draw up a draft compensation plan. A newspaper leak in March 1970 revealed that the committee would ask Chisso to pay only JPY2 million (USD5,600) for dead patients and JPY140,OOO to JPY200,OOO (USD390 to USD560) per year to surviving patients. The Arbitration Group was dismayed by the sums on offer.
They petitioned the committee, together with patients and supporters of the Litigation Group, for a fairer deal. The committee was forced to revise its plan and the patients waited inside the Ministry building for two days while they did so. The final agreement was signed on May 27. Payments for deaths ranged from JPYI . 7 million to JPY4 million (USD4,700 to USDI 1,100), one-time payments from JPYI million to JPY4. 2 million (USD2,760 to USDI 1,660) and annual payments of between JPY170,OOO and JPY380,OOO (USD470 to USDI , 100) for surviving patients.
On the day of the signing, the Minamata Citizens'' Council held a protest outside the Minamata factory gates. One of the Chisso trade unions held an eight-hour strike in protest at the poor treatment of the Arbitration Group by their own company. The verdict handed down on March 20, 1973 represented a complete victory for the patients of the Litigation Group. As of March 2001 , 2,265 victims have been officially certified (1,784 of whom have died) and over 10,000 people have received financial compensation from Chisso, although they are not recognized as official victims.
The issue of quantifying the impact of Minamata disease is complicated, as a full epidemiological study has never been conducted and patients were only ever recognized if they voluntarily applied to a Certification Council in order to seek financial compensation. Some people feared the disease to be contagious and many local people were fiercely loyal to Chisso, depending on the company for their livelihoods. In this atmosphere, sufferers were understandably reluctant to come forward and seek certification.
Despite these factors, over 17,000 people have applied to the Council for certification. Also, in recognizing an applicant as a Minamata disease sufferer, the Certification Council qualified that patient to receive financial compensation from Chisso. As such, the Council has always been under immense pressure to reject claimants and minimize the financial burden placed on Chisso. Rather than being a Council of medical recognition, the decisions of the Council were always affected by the economic and olitical factors surrounding Minamata and the Chissocorporation.
Furthermore, compensation of the victims led to continued strife in the community, including unfounded accusations that some of the people who sought compensation did not actually suffer from the disease. DISCRIMINATION OF VICTIMS:-When the first cases were reported and subsequently suppressed, the rights of the victims were not their communities due to ignorance about the disease, as people were afraid that it was contagious. The people directly impacted by the pollution of Minamata Bay were not originally allowed to participate in actions that would affect their future.
Disease victims, fishing families, and company employees were excluded from the debate. Progress occurred when Minamata victims were finally allowed to come to a meeting to discuss the issue. As a result, postwar Japan took a small step towards democracy. Through the evolution of public sentiments, the victims and environmental protesters were able to acquire standing and proceed more effectively in their cause. The involvement of the press also aided the process of democratization because it caused more people to become aware of the facts of Minamata disease and the pollution that caused it.
Although the environmental protests did result in Japan being more democratized, it did not completely rid Japan of the system that first suppressed the fishermen and victims of Minamata disease. PRESENT SITUATION Minamata disease remains an important issue in contemporary Japanese society. Lawsuits against Chisso and the prefectural and national governments are still continuing and many regard the government responses to date as inadequate. A memorial service was held at the Minamata Disease Municipal Museum on May 1, 2006 to mark 50 years since the official discovery of the disease.
Despite bad weather, the service was attended by over 600 people, including Chisso chairman ShunkichiGoto and Environment Minister Yuriko Koike. Most congenital patients are now in their forties and fifties and their health is deteriorating. Their parents, who are often their only source of care, are into their seventies or eighties or already deceased. Often these patients find themselves tied to their own homes and the care of their family, in effective isolation from the local community. Some welfare facilities for patients do exist.
One notable example is Hot House, a vocational training center or congenital patients as well as other disabled people in the Minamata area. Hot House members are also involved in raising awareness of Minamata disease, often attending conferences and seminars as well as making regular visits to elementary schools throughout Kumamoto Prefecture. DREDGING:- This process uses cutterless hydraulic dredging ships , suction heads, turbidity meters and cameras . Mercury was mainly contained in the upper thin layer of sediment in the bay [Density of mercury (13. 34 g•cm3)] , whereas a 50 cm-thick layer of sediment was dredged from the inner part of the bay by the suction heads in he ship. And then they are allowed for separation in the ship''s hull. Dredged material are discharged into reclamation area up to sea level and covered with geotextiles (permeable fabrics that are used to separate, filter, reinforce, protect, and contain). And lightweight volcanic ash and good soil placed over the geotextile. Then the effluent are discharged back to sea could not contain more than 0. 05 ppm of Hg.
Phytoremediation technologies:- This method is by the use of Hg-resistant bacteria which have been reported to produce enzymes that catalyze 2 rxns (1)Organomercurial Iyase - which removes ethyl group from mercury to create ionic mercury and(2)Mercuric ion reductase which converts ionic Hg to volatile elemental mercury. Plants engineered to express these genes could have potential for relatively inexpensive cleanup of Hg contaminated sites. volatilization of elemental Hg would allow Hg to diffuse out of the plant and into the atm at diffuse and non-toxic concentration.
DETOXIFICATION OF MERCURY:- This method is based on the fact that Elemental Mercury (Hgo)is non- toxic. Thecmethods of converting it is(1)Methanogens breakdown CH3Hg+ to form Hgo CH3Hg+ CH4 + Hgo 2)Exposure to ultra-violet rays is another method to breakdown methyl mercury (3)Sunlight will breakdown CH3Hg+ to form Hgo NEW ORGANISATIONS:- Today also there are many victims of this disease suffering from the problems of the disease with out getting sufficient combensation and consideration.
So a new organisation should come to take the problems faced by these people to the media so that it will come to the notice of the world. only then, effective solutions for the problems can be found. REFERENCES 1 . http://www. eoearth. org/article/Minamata_Disease 2. http://en. wikipedia. org/wiki/Minamata_disease 3. http://minamatadisease. net
No comments:
Post a Comment