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Arsenic poisoning in 1955, Morinaga Milk, Japan


As described in "Industrial Pollution in Japan", UNU, edited by Jun Ui, from June 1955 some infants in western Japan came down with diarrhoea or constipation, vomiting, a swollen abdomen, and a darkening of skin colour. There was no clue as to the cause of this commonly seen problem. On 23 July, the first infant patient of the Morinaga MF Milk poisonings was seen at Okayama University Medical School Hospital, and then one infant after another was brought into the hospital. On 5 August it was made clear that what the infants had in common was the intake of the MF milk formula...

More babies came to be hospitalized in the Okayama Red Cross Hospital, and on 13 August the chief of paediatrics became aware that the strange sickness was related to products from the Tokushima plant of the Morinaga Milk Company. On 19 August, Professor Eiji Hamamoto of the Paediatric Department of Okayama University advised the production chief at the Tokushima plant that several points in the production process should be examined for imperfections.  On 22 August, the Medical Department of Okayama University requested that Professor Hamamoto make a radio announcement regarding the arsenic-laced MF milk, but instead of making the issue clear through a radio message, Professor Hamamoto went to see the patients in the Red Cross Hospital. When the staff asked him what treatment should be given to the severe cases, at long last he ordered them to use the BAL antidote for arsenic poisoning. The next day... Professor Hamamoto reported the case to the Public Health Department of Okayama Prefecture. He did this 18 days after MF milk was found to be the causative agent.   On 24 August, the Public Health Department of Okayama Prefecture made a public announcement that poison had been found in MF milk. The government's Ministry of Public Welfare issued an order for all MF milk to be withdrawn from the market and the Tokushima plant of the Morinaga Company to be closed... After that there was a rush of families to the medical clinics, fearing for the life and health of their new-born babies.

The next day the Morinaga Milk Company placed an "Apology and Petition" in every newspaper... However, ML milk, produced at the Matsumoto plant, and MC milk, produced at the Hiratsuka plant, was also found to be tainted with arsenic.

At that time the parents of the infant victims being treated at the Red Cross Hospital, Okayama University Hospital, and Kurashiki Central Hospital came together to organize the Victim Patient Families Association. On 30 September, the Okayama association made the following three demands in relation to the incident:  (a) that the company pay all expenses in relation to essential treatment, hospitalization, and hospital visits; (b) that compensation be provided by the company in relation to the poisoning aftereffects; and (c) that compensation be set at 2,500,000 yen ($6,942) for each death caused, 700,000 yen ($1,943) for relatively seriously affected cases, and 300,000 yen ($833) for lesser degrees of poison-related degenerative involvement.

The company did not respond to these demands from the victims' families, and so the struggle was organized on a nationwide basis to put pressure on the company. On 19 September, victims' representatives from nine prefectures held a meeting in Okayama City, and decided to form Zenkyo (Morinaga Milk Victims' Association) and to press for action in relation to their three demands. After that representatives from four more prefectures joined Zenkyo, and thus all the victims were united.  On 5 October, at the first central negotiation meeting, Zenkyo requested that Morinaga pay compensation...  However, the number of victims was much larger than had been expected and the company appealed to the government to form an advisory committee. On 21 October, the Ministry of Public Welfare created, without consulting Zenkyo, a five-member committee... The Five-member Committee was to be a third party, and therefore neutral, but committee members' expenses were paid by the Yukijirushi, Meiji, and Morinaga bottled milk companies; this came under critical fire, since it appeared that the committee had been constituted in an attempt to lower the amount of compensation that the company would have to pay for the poisonings.

A subcommittee, which was to determine the standards upon which patients were to be evaluated, was formed under the Five-member Committee, with six members including Professor Hamamoto and the chairman, Nishizawa, who stated that the after-effects of the poisonings were of little consequence. The members of the subcommittee were paediatric specialists who were promoting bottle-milk, as desired by the milk industry...  On 5 December, the Five-member Committee announced the results of their deliberations, which were far from meeting the demands of the victims' families. These deliberations resulted in the following proposals: (1) that Morinaga be required to pay 250,000 yen ($694) for each death caused by the poisonings; (2) that 10,000 yen ($27.77) be provided for each patient; (3) that 2,000 yen ($5.55) in addition be provided for each hospitalized patient; (4) that it should be agreed that the poisoning has no lasting after-effects.  Zenkyo was very surprised and disappointed at these proposals and as a result decided to negotiate directly with the company. Zenkyo's demands were: (1) that the company compensate families of dead poisoning victims to the tune of 500,000 yen ($1,388); (2) that the company provide regular medical examinations for the living victims of the poisonings; (3) that a research institute be established to further progress in overcoming the lasting effects of the poisonings. On 26 December, Morinaga indicated that none of these proposals was acceptable.

Zenkyo protested to the Ministry of Public Welfare and organized demonstrations in concert with the prefectural associations, calling for a nationwide boycott of Morinaga products and staging sitdown demonstrations and strikes at Morinaga branch offices. However, public opinion was not as fully supportive of the victims as once was the case, and at the same time the funds to pay for hospitalization were running out. Also, at about the same time, the mothers supporting Zenkyo had to abandon their protest activities because of sheer exhaustion... Zenkyo gained nothing for its efforts, but some people belonging to the Okayama association of Zenkyo decided to file a suit in the civil courts.

In February 1957, the Morinaga Milk Company established the Morinaga Service Foundation with the express purpose of improving infant nutrition and the quality of all milk products. This foundation was completely different in nature from that proposed by Zenkyo for research into the after-effects of the arsenic-laced baby-milk poisonings. The formation of the service foundation was intended to counter criticism from professionals and promoters of mother's milk through the use of medical and bureaucratic authority and to silence certain vociferous opponents of the company...

After Zenkyo had been disbanded, an organization was established in Okayama Prefecture for the express purpose of providing protection for the Morinaga arsenic milk-poisoned children. In conjunction with other related organizations, it pursued activities to ensure that children's rights would be protected. In July 1957, this new organization entered into negotiations with Morinaga in which they demanded and received a memorandum from the company that acknowledged the company's responsibility in paying for periodic medical examinations for those infants who had been poisoned. Then, 19 of the poisoning victims received medical confirmation that they were indeed suffering from the after-effects of the arsenic-laced milk...  In October 1963, the Tokushima District Court handed down a not guilty verdict in the case against the Morinaga Milk Company, and this was felt to be a great betrayal of the parents of the poisoning victims. Angered by the unfair court decision, this same group decided to spread their movement throughout the country in order to continue the struggle for the poisoning victims. Then in March 1966 the Takamatsu High Court reversed the Tokushima District Court decision and sent the case back to the district court for retrial. In the same year, the Okayama Association against Medicine Poisonings (a private organization) proved through careful surveys that the MF milk poisonings had serious after-effects. This higher court decision and the advent of a supporting medical team provided a glimmer of hope for the victim families.

After 14 years...  no survey had been made of the problem. At this point the children were 14 to 15 years of age. There were those who thought a survey should be made before the children left compulsory education. These were persons involved in special education programmes for the handicapped and in nursing the said people as well as doctors in the same fields. This group organized a survey of the Morinaga arsenic-poisoning victims under the guidance of Professor Maruyama of the Medical Department of Osaka University. They interviewed many of the parents of the victims in order to discover what the after-effects were, how the children were getting along at 14 years of age, and what the parents were thinking and feeling. The survey was completed and made into mimeographed copies containing 93 pages. The title of the work was "Visit after 14 Years" and contained interviews with 68 people. 80 per cent of whom were found to have definite aftereffects and abnormalities.

With Associate Professor Hideyasu Aoyama of Okayama University Medical Department, Professor Maruyama held a press conference on 18 October 1969 to publicize "Visit after 14 Years." It was a time when there was increasing public interest in the issue. The Victims' Protest Association continued its struggle with some hope of light at the end of the tunnel. On 30 October, the same survey was reported to the Japan Academy of Public Hygiene...  Therefore, in autumn 1969, after a period of 14 years, the matter of the arsenic poisoning was once again discussed in the Japan Academy of Public Hygiene.

Many of the victims" parents were encouraged by the Maruyama Report, and once again a Morinaga Arsenic Milk Poisoning Protection Association was formed... In December 1969, the association issued its first publication named Hikari (Light) and also set up its headquarters in Osaka. In 1970, branches of the association were set up in Nara, Hiroshima, Kagawa, Kyoto, Hyogo, and Osaka in order to expand the influence of the organization and to provide suitable measures in relation to local problems. The organization expanded but the members took great care lest the mistakes of the past association be repeated. At the new protection association national meeting, the following four goals were decided upon with the shared understanding that the past organization had been divided over demands for compensation, and that it had been won over by the company: 1. To demand a complete cure as well as full protection for the victims.

2. To make further surveys of the after-effects of poisoning in co-operation with humanitarian medical doctors.

3. To discern and define the extent of responsibility for the problem that should be shouldered by the Morinaga Company.  In comparison to the situation surrounding the 1955 protection association, the new association had a much better chance of success, for there were growing public demands for control of pollution and the anti-pollution movements were in the making. The mass media were also calling for pollution elimination... Because of the irresponsible attitude taken by Morinaga and the Ministry of Public Welfare, conscientious scholars and young researchers began to make patient examinations in a co-operative effort with the parents of the victims and the protection association in January 1970. The researchers found some very definite after-effects of the poisonings, tried to discover effective treatments for the problem, and provided immunological analyses relative to victim medical prognosis. Osaka and Okayama universities became the centres for these studies, and Professor Maruyama organized a committee to survey the after-effects of the poisonings in co-operation with the Japan Public Hygiene Academy, the Japan Paediatrics Academy, and the Japan Hygiene Academy.

The parents making up the protection association gave their support to these efforts in co-operation with medical doctors and citizens' groups. In order to increase inter-group support the parents communicated with the PCB poisoning victims and Minamata disease patients in various districts,4 and visited labour unions, co-operative groups, consumer groups, small research groups, and universities in order to make their appeal in regard to the Morinaga poisoned-milk problem. One year after the Maruyama Report, the protection association had grown from a few family members to 800 persons. On 6 December 1970, the ninth national board meeting of the protection association decided to respond to Morinaga's proposal to carry on two negotiations at the same time - negotiations at the headquarters of the protection association and also with local associations. For negotiations at the headquarters, the protection association would select the date. On 12 December, representatives of the Morinaga Milk Company met with those of the protection association in Okayama, and thereafter, once a month until 11 July 1971, they met eight times for negotiations. The Morinaga Company tried purposely to delay the negotiations, and at the eighth meeting the company announced that no further discussions would take place ... Bowing to pressure from the protection association and also from public opinion, the Ministry of Public Welfare agreed to make examinations of the poisoning victims. However, playing on an old theme, the government commissioned a third-party group composed of so-called scholars and authorities, and this group came up with the conclusions that no after-effects existed. The Ministry of Public Welfare decided to examine victims in Okayama City, where the headquarters of the protection association were situated, and commissioned Okayama Prefecture to carry out the study. The Okayama Prefectural Public Health Department, the organ responsible for the examinations, in October established another committee for Okayama Prefecture arsenic-poisoning victims...  Citing the need to respect the privacy of the children involved, the contents and results of the examinations were not made known to the protection association or to the doctors who had made their own private examinations. The protection association was afraid that the same conclusions would be reached as in 1955, when there was a closed-door policy that was not responsive to the real needs and facts of the case. It therefore protested to the Ministry of Public Welfare and to Okayama Prefecture. But the administration forcefully carried out its closed-door policy. The report was made to Okayama Prefecture in December 1972, and the conclusion was that there was no special need for the patients to worry. This was the type of conclusion that the protection association feared most. It was clear from the exchanges in the National Diet sessions in relation to the findings of the report that Morinaga had paid 10 million yen and the Ministry of Public Welfare 1.3 million yen to have the report completed.

The protection association ... roundly criticized the Morinaga Company for its intention to use the report as a means of reducing its liability. Further, public opinion was at this time in full support of the protection association. Many citizens who were fully aware of the seriousness of the pollution problems at that time started a boycott movement against Morinaga products in the hope of forcing the company into accepting proper responsibility for the poisonings... from autumn 1970 this boycott began to spread to all parts of the nation. The Morinaga Company had not expected this, and, five months after withdrawing from the negotiations, company headquarters personnel came again to the table in order to try to avert the bad publicity they were sustaining ... Because of Morinaga's insincere response to the initiatives of the protection association, the movement decided to strengthen its bargaining position vis-a-vis the company. In August of 1972 at the fourth national assembly of the association, it was decided that permanent measures should be specified for the victims of the Morinaga arsenic milk poisoning... This involved the payment of compensation for those who had died as well as those who were still suffering the after-effects of the poisoning. The demands for compensation included remuneration for all victims who were drinkers of Morinaga Milk in 1955, including even those patients who were not registered as suffering from the after-effects. This demand was qualitatively different from other demands made in regard to pollution-related diseases, because in the other cases the victims were recognized as patients for compensation only on the basis of specific symptoms caused by specific pollutants ingested in specific amounts. This was epoch-making within the context of victim compensation negotiations related to environmental destruction...  In December 1972...  a resolution was passed to further boycott all Morinaga products until the company met all its obligations and to take the damage claims to the civil courts. The boycott movement against Morinaga products was already nationwide, and with these resolutions it spread like wildfire all over Japan. Morinaga stocks had dropped in value ever since the "Visit after 14 Years" report... Before the boycott movement had got under way, the Morinaga Company held 45 per cent of the market for powdered baby milk, but after the boycott started that share went down to 17-18 per cent...

In April 1973, members of the Kinki branch of the protection association filed a suit for damages against the Morinaga Company in the Osaka District Civil Court. In the same year a lawsuit, was begun in the Okayama District Court in August and in the Takamatsu District Court in November, in the hope that the civil cases would work to clarify Morinaga's responsibility for the poisonings. The Tokushima District Court case was reopened and in March 1973, after the Public Prosecutor had brought charges, the director and production chiefs of the Morinaga Company were sentenced to five years in jail. the longest sentences of this kind in Japan's legal history... The boycott of Morinaga products and the court cases were the two most important aspects of the protection association movement and both were long-term measures. The government was criticized for its collusion with the Morinaga Company, but the former was forced to distance itself from Morinaga when the company began to experience difficulties. In September 1973, the government finally recognized its responsibility, at least in part, and proposed a three-party negotiation arrangement between the protection association. the government administration, and the Morinaga Company. At the fifth negotiation session on 23 December 1973, an agreement was reached between the chairperson of the protection association, the Minister of Public Welfare, and the President of the Morinaga Company. This signed agreement contained five items. In summary, the agreement reached attributed full responsibility to the Morinaga Company for the original problem. It designated the establishment of a committee as proposed by the association, which would work out all unsolved problems. The said committee would respect all proposals of the association as well as have all its expenses paid by the Morinaga Company. The company would co-operate in the realization of a long-term reorganization plan proposed by the Ministry of Public Welfare. Finally, the three-party negotiation meetings would be continued until all problems could be completely solved.

In April 1974, the sixth negotiation meeting was held, followed by a seventh meeting for the establishment of the Hikari Foundation as an organ designed to help relieve the Morinaga milk-poisoning victims while various other specific issues in relation to the Foundation were being discussed and decided. The three-party negotiations between the protection association, the government, and the Morinaga Company continued alongside the litigation and the boycott. Then, on 28 November 1973, the Tokushima District Court also sentenced the production section chief of the Morinaga Company to three years in prison. The boycott movement continued to spread with increasing rapidity.

In April of 1974, the Hikari Foundation was established in order to help the Morinaga poisoning victims. It took 19 years for this organization to be formed... The Hikari Foundation was headquartered in Osaka where a committee, composed of professional doctors and educators, was founded. The district offices were located so as best to provide services to the many victims of the poisoning. As of 1981, there were 17 district offices, managed by parents involved in the protection association. There was also a great deal of co-operation from medical doctors and from people working in special education.

By the end of March 1983, there were 13,396 victims of the Morinaga milk poisonings, and 6,389 of these were in communication with the Hikari Foundation.

Basic Data

Name of conflict:Arsenic poisoning in 1955, Morinaga Milk, Japan
State or province:Okayama prefecture and neighbouring regions
Location of conflict:Okayama University
Accuracy of locationMEDIUM (Regional level)

Source of Conflict

Type of conflict. 1st level:Industrial and Utilities conflicts
Type of conflict. 2nd level:Chemical industries
Specific commodities:Poisoned milk
Chemical products

Project Details and Actors

Project details

In 1955, Japanese babies began getting sick. It took a long time — inexcusably long — for the danger to be publicly announced, and as a result, Japan had over ten thousand victims of arsenic poisoning, and over 100 deaths. In the 1970s, the Morinaga company was subject to civil society boycott, and was found guilty in civil and criminal court cases. There were involved negotiations for twenty years on the exact amounts for compensation (of a few thousand USD mortal victim).

Brett Walket (Toxic Archipelago, p. 95) gives these figures for 1981: 13389 ingested the milk, 600 died, 6093 with health difficulties, 624 plagued with retardation.

Type of populationUrban
Affected Population:13,400 victims
Start of the conflict:1955
End of the conflict:1983
Company names or state enterprises:Morinaga milk company from Japan
Relevant government actors:Public Health Department of Okayama Prefecture.
Ministry of Public Health and Welfare, Japan.
University of Okayama.
Environmental justice organizations (and other supporters) and their websites, if available:Zenkyo (Morinaga Milk Victims Association).
Hikari Foundation.

Conflict and Mobilization

IntensityMEDIUM (street protests, visible mobilization)
Reaction stageMobilization for reparations once impacts have been felt
Groups mobilizing:Local ejos
Local scientists/professionals
Forms of mobilization:Community-based participative research (popular epidemiology studies, etc..)
Creation of alternative reports/knowledge
Development of a network/collective action
Lawsuits, court cases, judicial activism
Media based activism/alternative media
Public campaigns
Street protest/marches
Boycotts of companies-products
Zenkyo (victims' association) resorted to demonstrations, calling for a nationwide boycott of Morinaga products and staging sitdowns and strikes at Morinaga branch offices. Monetary compensation was also discussed in detail over many years.

Impacts of the project

Environmental ImpactsPotential: Genetic contamination
Health ImpactsVisible: Exposure to unknown or uncertain complex risks (radiation, etc…), Deaths, Other environmental related diseases, Other Health impacts
Other Health impactsMany deaths and chronic impairements related to arsenic poisoning, initially denied by the company and by some medical personnel.
Socio-economical ImpactsVisible: Increase in Corruption/Co-optation of different actors, Violations of human rights, Specific impacts on women


Project StatusStopped
Conflict outcome / response:Compensation
Court decision (victory for environmental justice)
Negotiated alternative solution
Withdrawal of company/investment
Many deaths of victims of poisoning but not deaths of environmental defenders.
Development of alternatives:The Hikari Foundation was set up after many years, to help take care of the victims. The victims association (Zenkyo) had resorted to national boycotts of the company, court cases, street demonstrations...
Do you consider this an environmental justice success? Was environmental justice served?:Not Sure
Briefly explain:After many years, the Morinaga Milk company was found guilty in civil and criminal court cases, with some prison sentences. Indemnities for the victims and their families were small. The Morinaga Milk company exists to this day.

Sources and Materials

References to published books, academic articles, movies or published documentaries

Brett Walker, Toxic Archipelago. A History of Industrial Disease in Japan. Foreword by William Cronon. Univ of Washington Press, 2011.

The arsenic milk poisoning incident and the Morinaga Company's Response, in Jun Ui ed., Industrial Pollution in Japan, UN University (a full report)
UNU publication,

chapter 5 on the Morinaga Milk case, in Philippe Grandjean, Only One Chance. How Environmental Pollution Impairs Brain Development — and How to Protect the Brains of the Next Generation, Oxford UP, 2013.

Shigeto Tsuru, The Political Economy of the Environment. The case of Japan. Bloomsbury, London, p. 159 f.

Epidemiological Studies on the Morinaga Powdered Milk Poisoning Incident, Nippon Eiseigaku Zasshi (Japanese Journal of Hygiene) 27(6), 500-531, by Mashiko Ohira and Hidesayu Aoyama, 1972

Links to general newspaper articles, blogs or other websites

The Morinaga Milk Arsenic Poisoning Incident: 50 Years On.

A report outlining the Implementation Status of the Victims Relief Project.

Other documents

Meta information

Contributor:JMA (suggested by Kenichi Matsui)
Last update25/12/2016