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Chapter - 4 Minamata disease

I. The Nippon Chisso Company: Beginnings
II. The beginnings of the carbide organic chemical complex
III. Recovering from the defeat of the Second World War
IV. The discovery of Minamata disease and the difficulty in determining its cause
V. Social trauma and the fishermen's riot
VI. Counteraction and unconcern
VII. Rediscovery of the Minamata disease in Niigata
VIII. Government understandings, renegotiations, and interventions
IX. Taking the Minamata disease case to court and citizen support
X. In search of the Minamata disease
XI. Sit-down strike at Chisso Company Headquarters - Seeking direct negotiations
XII. The third Minamata disease and administrative-level perfidy
XIII. Minamata disease victims' movements and efforts at renewal
XIV. Conclusion

Jun Ui

The Minamata disease was the most massive pollution problem to strike Japan in the post-Second World War period. The total picture in relation to the epidemiology of the problem has yet to unfold. The number of victims and deaths produced has not yet been determined. Twenty-five years have come and gone since the disease was first discovered and the number of people adversely affected is still on the increase. Further, no treatment for the condition has been discovered. Serious attempts to ferret out the cause of the original disease were shelved, and it was not until the occurrence of the same disease in another location that determined efforts were again undertaken in this regard. If it had not been for the second outbreak of the disease, no one would have bothered to look for the cause. The orientations assumed and the reactions exhibited by the business sector, governmental administration, the scientific community, and public opinion were all typical of the Japanese socioeconomic situation in relation to pollution issues.

As the leader in the chemical industry field and the original Minamata disease polluter, Nippon Chisso's manufacturing facility in Minamata City is characteristic of the Japanese chemical industry sector, in which great efforts were made to adapt to various modes of Western technology. There were many chemical substances produced for the first time in Japan at the Chisso Minamata complex and the corporation maintained a tight hold on production secrets, to prevent competition from other manufacturers. Before the Second World War, this same corporation expanded into those nations colonized by Japan. Even though there were delays in Japan's capital expansion, the company built Japan's largest electro-chemical industrial complex, which provided the initial thrust for Nippon Chisso chemical industries in China and Korea. After the end of the war, the company seemed certain to collapse, but like the phoenix it rose again from the ashes, beginning the mass production of plastics from which it derived large profits because of its monopoly practices and the mass-consumption economy in which it operated. The Chisso Minamata complex, being representative of Japan's chemical industries during the post-war years, proved again the importance of technological prowess in the successful production of chemical substances. The complex achieved the highest economic growth-rate in Japan and at the same time caused the greatest environmental destruction that the country has ever seen.

I. The Nippon Chisso Company: Beginnings

The village of Minamata, located on the west coast of southern Kyushu, was traditionally supported by rice farming and by a cove in the port which allowed the production of salt. All this was well established by the beginning of the twentieth century. Across the bay is Amakusa Island, which produced some coal; there was also a gold mine in the mountains. These materials were brought into Minamata village and wood and mountain products were shipped from the port. Otherwise, Minamata was no different from other villages found throughout the country.

With experience in a successful venture to establish Japan's first industrial carbide production, Jun Noguchi, a young college-educated electrical engineer, was looking for a site to construct a new carbide production plant that would use surplus electricity from a hydro-electric power plant he had helped build as a power source for the gold-mining operation in the hinterland mountain area. At about the same time, the salt production, Minamata's only local cash-earning industry, became a government monopoly and was about to lose its viability as a profitable enterprise. The leaders of Minamata village, sensing an urgent need for new industries, approached Noguchi and urged him to build the new carbide plant in the village. To the hesitant Noguchi, who maintained that there were a number of other good locations to site the plant, the village leaders offered to provide free, or at extremely favourable rates, the use of the land that had been used for salt production, together with industrial water and the port facility; they also offered to shoulder the cost of extending the power line from the power plant to the carbide production facility.

With these inducements, the company decided to build its factory in Minamata. Those who had been working in the coal mine and had been put out of work by the introduction of electricity were hired at low wages to work in the new Chisso plant. This was seen as another important reason for providing inducements to the Chisso manufacturing facility to come to Minamata. The furtherance of Japan's high-economic-growth policies, which were based on the exploitation of cheap local labour and instituted under the guise of industrial restructuring, had already begun with the introduction of the new Chisso factory.

The Nippon Chisso Company production facility began functioning under very favourable conditions, but the product itself did not sell well, since the demand for carbide was low; its main use was as a light source in night fishing. The company then began using carbide as a material from which to derive calcium cynamide, which was then used to produce metamorphic ammonium sulphate to be used as an agricultural fertilizer. In this manner the company was saved from going under, but, in the face of fierce international competition in chemical fertilizers, it was taken over by a railway concern and also bolstered by the injection of Mitsubishi Corporation capital. For this small fertilizer production facility, the advent of the First World War meant a firmer grasp on survival. The importation of fertilizers was halted and Chisso gained a monopoly position in the domestic market. The losses incurred at first were covered and Japan's chemical industry became prosperous. Nippon Chisso began with capital assets of 1 million yen, and in 1920, after the First World War, had assets of 22 million yen; within the ensuing half-year period it was paying dividends at the 104 per cent level. Immediately after the First World War, Noguchi visited Europe and on that occasion decided to introduce the new Casale ammonia synthesis technology into Japan, although it was still at the pilot-plant stage. This was for Japan the first experience of ammonia synthesis and the first introduction of high-pressure gas technology.

In the depression after the First World War, it was difficult, from both a managerial and technical point of view, to construct a new manufacturing facility, based upon new technology, that would also be able to produce a greater amount of fertilizer in a shorter operating period. In this regard, the Nippon Chisso technical staff worked very hard to overcome various difficulties. In 1923 the first ammonium sulphate compound was produced at the Nippon Chisso Nobeoka complex. From that year on, management was able to weather the depression period with a relative degree of calm. Nippon Chisso was not only dominant in the expanding fertilizer market but also based its solvency on the provision of inexpensive hydro-electric power. Since the major hydro-electric power plants in Japan were provided and controlled by the major Japanese zaibatsu, Nippon Chisso went into Korea, on the basis of hydro-electric power-plant provision, at a time when many Japanese companies were contributing to the colonization effort. At the same time, the Nippon Chisso Minamata facility began using the Casale process for the mass production of ammonium sulphate, a method that had been successfully introduced at the Nobeoka facility. Although there were many explosions resulting from the use of this new high-pressure gas process, in 1927 ammonium sulphate production was successfully instituted, and this gave Nippon Chisso the new status of a rising capital venture based upon the cyclical production of fertilizer compounds. In that same year construction of the Nippon Chisso Hungnum (Korea) facility was started. It was to become the largest electrochemical compound production facility in Asia, with the largest attendant electric power station seen at that time. In 1930, the Hungnum plant started operations, and the corporate advance into the colonies of Japan was assured. In the trial and initiation periods of the 1920s, the fertilizer production facility was a major pillar in the recently rising chemical industry. The newly founded Nippon Chisso company was able to weather all pressures from both inside and outside the country, and to take a major role in the chemical industry through the technical prowess that comes with experience. Although the original technology was introduced into Japan from outside, the company was able to expand and increase both its base of operations and its production facilities so as to be ready for the next series of developments, which originated from its own technology.

II. The beginnings of the carbide organic chemical complex

It was in 1930 that Japan's chemical industry turned to organic chemical compounds derived from calcium-carbide-generated acetylene. It was known at that time that acetylene blown over mercuric sulphate would pick up one water molecule to produce acetaldehyde. Industrial production was late in coming but Nippon Chisso developed its own techniques and produced not only acetic acid, which is a direct derivative of acetaldehyde, but also, on an experimental basis, such downstream products as ethyl acetate, cellulose acetate, vinyl acetylene, acetone, butanol, and isooctane. From the introduction of foreign technology into Japan came unique methods suitable to the conditions in Japan and, on the basis of this, effective policies were developed. In this manner the development of organic chemistry in the factory placed Chisso on the most advanced chemical engineering level.

Production of the new product was first tried on an experimental basis at the Minamata facility, and then full-scale production was initiated. The same production techniques were then used in other installations, such as the one in Hungnum, Korea, with total output increasing very rapidly. These technical advancements were made possible by the highly trained technicians and workers at the Minamata facility. For instance, unless a person was proven to be among the top graduates of the Department of Engineering at Tokyo Imperial University, where the highest educational levels in Japan were to be attained, he would not be allowed to sit for the employment examinations at the Minamata complex. The same thing was true for the regular workers who sought employment. Only the very best graduates of junior high schools were employed on a probational basis as assistants to company staff; then, only after the probational period had been successfully completed were they hired as fully fledged factory personnel. Noguchi would say that factory workers should be used like cows and horses, and in fact they were treated like animals, being made to work under the most dangerous conditions and with very little remuneration. In the experimental pilot plants, there were often explosions and accidents, and dangerous materials were kept on hand, and, unless the workers acknowledged a willingness to work under conditions where they would be risking their lives, they were not employed. Through the pre- and post-Second World War periods, the employment of high-quality low-paid workers was the basis upon which Japan's industrial strength was built, and the Minamata complex was a perfect example of this phenomenon. If the workers were able to endure the most severe working conditions, they would in all likelihood be given the chance of being appointed as experts in the Chisso manufacturing complexes built in Japan's colonies. Working in the Minamata factory was considered to be one of the best tests of human endurance.

As the Chisso Minamata production facility grew, the village of Minamata prospered. With an increased population, the village became a town and then, during the Second World War, a city. The economic prosperity of the city depended on the Chisso plant, and public investments in roads and other infrastructures were prioritized around the manufacturing plant as the basic unit of industrial expansion. The town grew around the factory and the fundamental nature of the preprogrammed urban development was determined before and after the Second World War. The consciousness of those living in the city developed in such a way that they began to understand themselves as sharing, on the community level, the destiny of the Chisso chemical plant.

In the 1930s, when militarization in Japan was on the upswing, industrialization in Japan's colonies was also in an expansionary phase. In the early colonization period, the Nippon Chisso capitalists were closely allied with the military power of Japan that ruled the colonies. In this regard the company found itself in a favourable position or at least to have the same favoured status relative to facility construction preconditions, labour-force supply, and resource procurement as parallel zaibatsu-financed manufacturing facilities. In 1934, the company became independent of Mitsubishi capital, with which it had been associated from its inception, and then went on to establish its own zaibatsu in conjunction with the Kogyo and Chosen banks. Since Japan lacked natural petroleum resources, the energy for aeronautics and the materials that were otherwise derived from different aspects of petroleum chemistry became very important to the military, but the only alternatives had to be produced from acetylene-chemistry-based organic compounds. In this context Nippon Chisso was in a position to develop materials that were badly needed by the military, and with this background the company forged ahead in Korea and China. Acetaldehyde, which was produced from acetylene, was a key material, and Nippon Chisso was well advanced in the field of acetylene chemistry. In 1938, I.G. Farben, one of Germany's monopoly capitalists, announced the production of a vinyl chloride plasticizer, and in 1941 the Minamata plant successfully produced the same material. This was the only vinyl product made by Japan before and during the Second World War, but this fact alone indicates the relatively high level of acetylene chemistry that had been achieved in Japan.

It is an undeniable fact that the initial plans of Nippon Chisso were oriented toward the development of large-scale hydro-electric power-generation projects and major machine-industry capacities in relation to the construction of dams and hydro-electric generation projects, especially in Japan's colonies. However, since these technological pursuits required large-scale human labour resources and were also based on excessive human suffering, new developments in the machine-engineering and transportation fields were not forthcoming.

All the waste products that were the result of the rapid expansion of the Minamata production complex and of other manufacturing ventures were dumped without treatment into Minamata Bay, where they destroyed the fishery resources. The fishermen of Minamata brought their protests to the company many times but they were no equal to this massive industrial giant backed up by a powerful military establishment. The fishermen received compensation twice, once in 1926, and then again in 1943, at that time with the stipulation that there were to be no further demands on the company for compensation. The fact that the second series of negotiations took place during the war, and that the conditions for compensation included a demand by the company that no further requests be made, indicates the degree to which the aquatic environment had already been destroyed by the discharged wastes. One of the causes of Minamata disease was the company's monopoly power, which was characteristically blind to the damage produced by unbridled technology, as efforts were made to increase production without any regard for the problems caused to the human environment.

III. Recovering from the defeat of the Second World War

As a result of Japan's defeat at the end of the Second World War, Nippon Chisso lost all of its overseas assets - a total of 80 per cent of all assets held. The Chisso zaibatsu was ordered by the occupation forces to disband, and the Minamata complex had been destroyed by bombing during the war. However, out of this destruction the Minamata complex, which had a long-standing tradition of high technology combined with the samurai spirit, came back to life like the mythical phoenix. In the period of near starvation immediately after the war, food production was the highest priority, and for this the production of ammonium sulphate was needed as an agricultural chemical. In this situation the Chisso complex restarted production two months after the war ended. The workers went to villages with ammonium sulphate and salt to exchange for food. In this context also, the complex began again the production of acetaldehyde from acetylene. By employing the hydro-electric power-generation stations that had not been so heavily damaged during the war, the fertilizer and carbide electric hearth facilities recovered quickly. At the same time, one of the typical consumer products imported was polyvinyl chloride plastic. In the post-war period companies imported plastic-coated electric wire from the United States and reprocessed the coverings into nylon sheets and belts, which sold very well. The only installation in all Japan that could produce polyvinyl chloride was the Chisso Minamata complex, and in 1949, when the occupation army granted permission to reopen the facility, it once again marketed a monopoly product. The workers from the Chisso facilities in Japan's former colonies returned to Minamata and began energetic preparations for the rapid production revival that was to begin in the 1950s. In the confusing period after the war, the Minamata complex technicians worked very hard and, on the basis of their knowledge of acetylene-derived acetal-dehyde, in 1953 they successfully produced DOP, which is an essential plasticizer for the production of PVC.

The technical and commercial monopoly in relation to the expanding Japan PVC market was held through occupation army orders by American technology and capital, but the monopoly on the production of DOP for the Japanese market was fully retained by the Minamata complex. Within the context of the competitive 1950s, especially in relation to greatly expanding PVC markets, the Chisso Minamata complex was able to rebuild itself with phenomenal speed. For the production of octanol, the raw material from which DOP is made, the dual-carbon-atom acetaldehyde molecule was modified through a very sophisticated attachment of four more molecules. All of this was based on the long experience of acetylene chemistry maintained since before the war. Only the Minamata complex retained this high-level capacity for chemical synthesis, and because of this there were no other chemical companies able to recover so fully during that difficult period. It was in this way that the Minamata complex experienced a second golden era during the 1950s and regained a leading position in Japan's chemical industry. The Minamata complex, able to rebuild itself through the creativity of its personnel and the strength of its technology, stood in stark contrast to the old zaibatsu-supported chemical companies which, after the war, sought to revive their technological prowess through the purchase of foreign technology from the USA and other countries.

During the period when the Minamata complex was enjoying its greatest economic success, 60 per cent of all city taxes came from the chemical company and other related income sources. The mayor of the city was a retired director of the complex and a majority of the city council members were related in one way or another to the manufacturing facility. In the post-war period of so-called democratic politics, the city of Minamata was structured along typically feudalistic interactions and relationships centring around the chemical company and its manufacturing complex. Everyone knew that the level of economic prosperity enjoyed by the city depended on the rise and fall of the chemical company.

In the 1950s, the Minamata complex was able again to increase its capacity for the production of acetaldehyde and PVC and through this went on to sustain the largest production capacity in Japan. 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, and the aquatic environment was damaged even more than before the war, with devastating effects on the fishery industry there. The number of dead fish in the water increased and the number of fish caught was once again reduced. The local fishermen's association went to the chemical company for the third time to negotiate compensation. They managed to extract further amounts of money from the management, and exchanged certain areas of the bay with the company for use as reclaimed land, but all of these concessions were on condition that the association never again lodge protests with the company over company-induced pollution problems. At about this time people living in the city began noticing a strange new phenomenon, in which cats living in the city would go through a frenzied dance and ultimately throw themselves into the bay. The fishing community named this phenomenon "the suicide-prone group of dancing cats," and began to wonder if it did not portend misfortune in the future.

IV. The discovery of Minamata disease and the difficulty in determining its cause

In May 1956, four patients suffering from a yet unheard-of disease were brought to the city hospital. They all had common symptoms such as severe convulsions, intermittent loss of consciousness, repeated lapses into crazed mental states, and then finally permanent coma. Then, after the onset of a very high fever, they would die. Dr. Hosokawa, the director of the hospital, began an epidemiological survey of the immediate area in co-operation with local medical associations and health centres. The same type of patients had indeed been discovered in the fishing villages surrounding Minamata City and it was determined that 17 people in all had so far died after showing the same symptoms. This initial stage was characterized by a profound sense of shock at the high death-rate.

The initial survey indicated that the disease had not occurred suddenly but had been noticed by doctors before, except that it had not been recognized as a new disease. The one factor that was common to all patients was that they ate large amounts of fish from Minamata Bay. At first there were suspicions that the disease was contagious but this fear was laid to rest after more intensive surveys had been taken. Then there were thoughts that the cause might be related to toxic substances. At this point efforts at determining the cause of the disease were handed over to a medical research group at Kumamoto University in Kyushu. The group continued investigations for about two years but was not able to discover any definitive cause for the disease. It was, however, deduced that the fish and the shellfish in Minamata Bay were poisonous: toxic symptoms did in fact develop in laboratory animals which had been fed these same poisonous fishery products, but their symptoms seemed to be completely different from those seen in human patients.

The initial survey indicated that the common conditions surrounding all the patients made it almost certain that the problem was related to the Chisso Minamata chemical complex, but it was completely taboo to speak of this possibility in the community, with its complete economic dependence on the facility. The fish from Minamata Bay were poisoned to a much greater extent than fish taken from other locations, and all of the wastes from the chemical complex had been discharged into the bay for a very long period of time. Waste sludge taken from the bay contained so many different kinds and such huge amounts of poisons that there was no telling which of them was the cause. The sludge contained great amounts of manganese, selenium, and thallium, substances which could conceivably be related to the disease, although animal experiments resulted in very different symptoms. The research group asked the chemical company to indicate what substances were being used for production synthesis apart from the materials contained in the waste discharge, but the company was unwilling to co-operate in this regard. Furthermore, the engineering department of Kumamoto University, which had more precise information on the inner workings of the Minamata chemical complex, was predisposed not to co-operate with the medical research group. Finally, when the medical research team indicated that the probable cause of the Minamata disease was heavy metal poisoning, the chemical company provided their own report to dispute this theory.

Then, after two years of survey work, the medical research group was able to eliminate every pollutant one by one, until they came upon mercury as the last heavy metal in the list. At that time they did not know that mercury was employed in massive amounts in the chemical complex, and they also presumed that the company would probably not waste mercury, for it was a very expensive material. The company kept the use of mercury a production secret, although industrial circles and engineers were aware of it. There were massive amounts of mercury in the sludge taken from the bay, as well as in the poisonous fish and in the patients who had died of the disease. The epidemiological distribution of the disease among the human population was the same as the distribution of poisonous fish in Minamata Bay. The characteristics of the disease were the same as those encountered in alkyl mercury poisoning. The medical research group, which was severely criticized by the Chisso chemical company, continued its survey efforts for another year and in July 1959 came to the interim conclusion that mercury was the most probable cause of the Minamata disease.

V. Social trauma and the fishermen's riot

Three years had passed since the discovery of the disease, and the local fishermen's groups had had no grounds for expressing their pent-up resentment against the chemical company, because of the lack of hard evidence as to the cause. When, therefore, it was heard that the disease could possibly be the result of an organic mercury discharge, they exploded in anger. It was obvious that the managers of the chemical company would flatly and indignantly deny any culpability for the problem, stressing all the time that they had not discharged mercury, even though mercury was in fact essential to their chemical reactions. But the fishermen, concerned that their fish were no longer saleable and strengthened by the medical statement in their belief that the chemical complex was the cause of the disease, went again to the company management to demand compensation. At this time there were new disease patients discovered in an area along the sea-coast where the company had relocated its waste drainage pipes away from the original discharge location. As a result, fear spread to all areas of the Fushimi Sea and fish taken from the sea could no longer be sold because of fear of contamination. The economic base upon which the livelihood of the fishermen was built lost its viability, and the once proud and prosperous fishermen of the Fushimi Sea became beggars and wanderers.

From the summer and on through the autumn of 1959, the Minamata Fishermen's Association and the Fushimi Sea Fishermen's Association demanded compensation from the company for damage perpetrated by the chemical complex. The company refused to make any payments on the grounds that the cause of the disease was not understood to be related to the operation of the chemical complex. However, the company did decide to pay a small amount of sympathy money. During these negotiations with the fishermen the company would call in the police without hesitation. The social tensions in and around Minamata City rose to a crescendo, and on 2 November 1959, 4,000 Fushimi Sea fishermen congregated to demand a National Diet members' inspection of the polluted area. On the way home from this rally they broke into the grounds of the chemical complex and destroyed office equipment. This event was magnified by the national news media and the Minamata disease at last came to the attention of the Japanese populace as a whole, some three-and-a-half years after it was discovered. With the Minamata chemical complex labour union in the forefront, many groups, including the Japan Socialist Party, criticized the fishermen's riot. If this action had not been taken by the fishermen, the Minamata disease would never have become national news.

The then International Trade and Industry Minister, Hayato Ikeda (who in later years as Prime Minister initiated Japan's high-economic-growth policies) criticized the publication of the Kumamoto University research group's organic mercury theory, saying it was the cause of social conflict. As they were less than willing to make public any disagreement among members as to the relationships between organic mercury and the chemical complex effluent, the Ministry of Public Welfare's Minamata disease research group could only provide a very ambiguous and non-conclusive report, after which the said group was immediately disbanded. On the basis of very cursory and incomplete surveys of the problem, scholars and other public personages commissioned by the chemical company and the Ministry of International Trade and Industry came up with all kinds of differing theories as to possible causes of the Minamata disease.

During this period, Dr. Hosokawa, the director of Minamata City Hospital, while paying special attention to the treatment of disease patients, was also very interested in the organic mercury theory espoused by the Kumamoto University research group. He carried out animal experiments using cats, and, by feeding them the waste effluent from the chemical company's acetaldehyde production unit, was able to induce Minamata disease symptoms in them; he was later able to confirm the presence of disease through autopsy and pathological examination. The company executives were surprised by the fact that Dr. Hosokawa, the company doctor, was doing this kind of re search, but, while they forbade him to continue with these efforts, they used certain excerpted portions of his research report to support company contentions that the chemical production effluents were not to blame. As of October 1959, the Chisso Minamata Chemical Company was fully aware of the fact that the Minamata disease was related to the effluent discharge from the acetaldehyde production unit, but since this production unit was the keystone for all organic compound production processes, the company continued, in its relations with the outside world, to deny culpability.

By the end of 1959, as a result of intervention by the prefectural governor, the company decided to pay a total of 100 million yen (about US$ 27,800 at 1959 rates) to the fishermen's associations on the condition that the cause of the disease be discussed no further. At the same time it was decided that the Minamata Disease Association should be paid condolence money at the rate of 300,000 yen ($830) for each death caused by the disease and 100,000 yen ($278) for each living victim. The company emphasized that the money was only meant as condolence for people in trouble, and was not to be construed as an admission of culpability. However, the articles of negotiation prepared by company management as a basis of an understanding with the disease victims included both a prohibition on any further demands for compensation, even if it should be determined that the disease was caused by company-produced effluents, and a clause providing for an end to compensatory payments should it be proven that the disease was not related to production effluents. From these facts alone, it can be easily surmised that the company was fully aware of the cause-and-effect relationships between production effluents and the disease, and negotiated for small condolence payments on the basis of this knowledge. The government's Ministry of Social Welfare established a Minamata Disease Patient Examination Council, composed of selected medical practitioners, in order that patients could be screened so as to qualify for company-provided compensation. Only officially designated Minamata disease patients can qualify to receive money from the Chisso Chemical Company.

VI. Counteraction and unconcern

Public opinion was critical of the fishermen's direct action against the chemical company, though thinking varied as to the purported cause of the disease. Therefore, with the disease victims actually receiving monetary compensation, it was thought that the social conflict surrounding the Minamata disease had come to an end. With the start of the 1960s the problems laid bare by the Minamata disease were forgotten because of the overshadowing political and foreign-relations dimensions of the Japan-United States Security Treaty. The fishermen who were involved in the riot were punished. In order to come to some fair and definitive conclusion as to the causes of the disease, two third-party research groups were formed, one by the government and the other by the Japan Medical Association. Because of lack of funding the government group was disbanded within the year without reaching any conclusions. In spite of the fact that Dr. Tamiya of the Medical Department of Tokyo University - Japan's supposed authority on the subject, who was supported by the Chisso Chemical Company and other mercury-handling industries - was named convenor, the Japan Medical Association group was disbanded in 1962, also without reaching any conclusions. In this manner the issue was neutralized without the problems really being confronted.

Governmental funding for the Minamata disease research group at Kumamoto University was cut off, but the university continued its efforts to discover the causal mechanisms involved in the disease. In 1962 hygienics professor Irigayama was able to separate methyl mercury compounds from the catalytic wastes derived from acetaldehyde production processes. He made it very clear that these wastes were the cause of the Minamata disease, but he was ignored by much of the academic community. At the community hospital attached to the Chisso chemical complex, Dr. Hosokawa was working on orders from the company to provide evidence that would counter the methyl mercury poisoning theory, but he was able to convince Chisso executives that his original research should be continued in order that the Minamata disease cause be determined on the basis of company-developed methods. In 1962 Dr. Hosokawa came to the same conclusions about the cause of the disease as Kumamoto University's Professor Irigayama. However, the Chisso Company ordered that these findings be kept secret. At about the same time the Kumamoto prefectural government was doing research on levels of accumulated mercury found in human hair as indicators of mercury contamination in the body. The results of those efforts indicated high levels of mercury contamination in fishermen and their families who were living in communities surrounding Minamata City, but mercury contamination was also found in island communities in the Shiranui Sea. Unfortunately the results of this research were not announced and they passed into oblivion. Because of the heavy criticism that was brought to bear against the organic mercury theory advanced by Kumamoto University, Minamata disease recognition and designation was limited only to those patients where very special and obvious methyl mercury poisoning symptoms were recognizable as medical textbook cases. At the same time it must be remembered that the diagnosis of the disease in living patients was made for the purpose of getting monetary compensation from the chemical company, and these factors produced their own restrictive sociological consequences. As a result of these factors, there were no new disease patients discovered for a few years after 1960, and it was thereby concluded that the Minamata disease had run its course and was no longer a problem. During the early 1960s, then, the problems related to the Minamata disease were thought to be things of the past, and no more attention was paid to the particular issues involved. In Minamata City the greatest concern of the people had turned to a long strike in which the labour union was fighting a Chisso company plan to rationalize operations, but the company was victorious in that it was able to divide the labour union into smaller groups. Owing to a combination of all these factors, the problems of the Minamata disease were forgotten, and the victims themselves also wished to be left alone.

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