Arsenic poisoning in 1955, Morinaga Milk, Japan

Many babies who had taken arsenic-tainted milk produced by Morinaga Milk Industry died. A head of factory production was sentenced to jail after an 18 year long legal case. Families' alliances asked for compensation.


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...

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Basic Data
NameArsenic poisoning in 1955, Morinaga Milk, Japan
ProvinceOkayama prefecture and neighbouring regions
SiteOkayama 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 CommoditiesPoisoned milk
Chemical products
Project Details and Actors
Project DetailsIn 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
Potential Affected Population13,400 victims
Start Date1955
End Date1983
Company Names or State EnterprisesMorinaga milk company from Japan
Relevant government actorsPublic Health Department of Okayama Prefecture.

Ministry of Public Health and Welfare, Japan.

University of Okayama.
Environmental justice organisations and other supportersZenkyo (Morinaga Milk Victims Association).

Hikari Foundation.
The Conflict and the Mobilization
Intensity of Conflict (at highest level)MEDIUM (street protests, visible mobilization)
When did the mobilization beginMobilization for reparations once impacts have been felt
Groups MobilizingLocal ejos
Local scientists/professionals
Forms of MobilizationCommunity-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.
Environmental ImpactsPotential: Genetic contamination
Health ImpactsVisible: Exposure to unknown or uncertain complex risks (radiation, etc…), Deaths, Other environmental related diseases, Other Health impacts
OtherMany deaths and chronic impairements related to arsenic poisoning, initially denied by the company and by some medical personnel.
Socio-economic ImpactsVisible: Increase in Corruption/Co-optation of different actors, Violations of human rights, Specific impacts on women
Project StatusStopped
Pathways for conflict outcome / responseCompensation
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 AlternativesThe 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 as a success?Not Sure
Why? Explain briefly.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

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)
[click to view]

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
[click to view]


The Morinaga Milk Arsenic Poisoning Incident: 50 Years On.

A report outlining the Implementation Status of the Victims Relief Project.
[click to view]

Other Documents

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Meta Information
ContributorJMA (suggested by Kenichi Matsui)
Last update25/12/2016