Itai-Itai disease, Toyama prefecture, Japan

The outbreak of itai-itai disease, a painful chronic cadmium poisoning, took place along the Jinzū River for many decades. The cause of the disease was discharge from the Kamioka zinc mine belonging to Mitsui Mining and Smelting Co.


The outbreak of itai-itai disease, which is the most severe stage of chronic cadmium poisoning, took place in the Cd-polluted Jinzū River that flows from Gifu Prefecture to Toyama Prefecture. The cause of the disease was discharge from Kamioka Mine. The name itai.itai means "it hurts-it hurts", this name was given  by a newspaper to a disease that later was known to be originated by cadmium poisoning in this area of the Toyama Prefecture where  the river was contaminated by slag from the mine upstream; as a consequence, the soil in rice paddies was polluted with heavy metals including Cd through irrigation water from around 1910 to the 1960s.

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Basic Data
NameItai-Itai disease, Toyama prefecture, Japan
ProvinceToyama prefecture
Accuracy of LocationMEDIUM regional level
Source of Conflict
Type of Conflict (1st level)Industrial and Utilities conflicts
Type of Conflict (2nd level)Mineral processing
Metal refineries
Specific CommoditiesCadmium as pollutant
Project Details and Actors
Project DetailsLocated in Gifu prefecture close to the border with Toyama prefecture is the Kamioka Mine, one of the leading sources of zinc in Japan. The mine has a long history dating back to the Yoro era of the Nara period (around 720), when gold was discovered on the site and presented to the Imperial court. As the country’s rulers changed through the Muromachi, Azuchi-Momoyama and Edo periods, minerals continued to be extracted from the mine throughout. In the Meiji period, in 1874 the Mitsui clan acquired the Kamioka mine and began modern mining operations. From that point onwards, all the way through to the suspension of mining in June 2001, the mine continued to contribute to the supply of zinc and lead resources in Japan. In the early 1950s, the local Dr Noburu Hagino tought that, downstream of the Jinzu river, the itai-itai disease, a form of bone brittleness (osteomalacia), came from malnutrition but in 1957, the fact that the outbreak was concentrated in a limited area along the Jinzu River basin, lead him to announce his explanation that the "itai-itai disease was chronic cadmium poisoning caused by heavy metals such as zinc and lead contained in water of the Jinzu River." This was corroborated by epidemiological research conducted together with agronomist Kinichi Yoshioka. The Itai Itai disease of cadmium poisoning became one of the 'Four Major Kogai' Litigations' in the postwar period in Japan, four major industrial diseases. (Kogai means pollution). Mitsui Mining and Smelting Co. lost the court case. The Japan Mining Industry Association disputed the court findings still in the 1970s.

Those affected (mostly women) together with families, are many. The costs of the disease were enormous in personal and financial terms. The costs of decontamination of soils run into hundreds of millions of USD. By 1990 about 4,340 ha, or 66 % of the approximately 6,510 ha of the most highly cadmium contaminated farmland had been restored.
Project Area (in hectares)6500 ha contaminated
Type of PopulationSemi-urban
Potential Affected Population8000 (directly, and many more indirectly)
Start Date1932
Company Names or State EnterprisesMitsui Mining and Smelting Co. Ltd. from Japan
Relevant government actorsMinistry of Mines

Ministry of Health and Welfare

Toyama Prefecture

Environmental Agency ( established in 1971 as a government agency, started a research program on itai-itai disease and cadmium poisoning in 1974, inclined to deny the facts).
Environmental justice organisations and other supportersJinzu River Mining Pollution Prevention Council

Dr Noburo Hagino and other medical, chemical and agronomic experts (from the 1950s onwards)

Itai-itai Disease Residents’ Association (since 1966)

Itai-itai-byo Taisaku Kyogikai (Council on measures to aid Itai-itai disease victims), 2016
The Conflict and the Mobilization
Intensity of Conflict (at highest level)HIGH (widespread, mass mobilization, violence, arrests, etc...)
When did the mobilization beginMobilization for reparations once impacts have been felt
Groups MobilizingFarmers
Local ejos
Local government/political parties
Social movements
Trade unions
Local scientists/professionals
Two organizations with the same name, the Jinzu Mining Pollution Prevention Council (JMPPC), were established already before the 1950s, one led by heads of local administrations and the other led by heads of agriculture cooperatives. There is a history of conflict between groups of farmers and fishermen and large mining companies from the early 20th century in various parts of Japan (as in the Ashio mine). It was not unusual for companies to pay compensation to the complaining groups in the damaged areas. The owners of the Kamioka mine paid money to complaining groups every year from 1949 to 1954 (Kaji, 2012), much before the court case..
Fisher people
Forms of MobilizationCommunity-based participative research (popular epidemiology studies, etc..)
Creation of alternative reports/knowledge
Involvement of national and international NGOs
Lawsuits, court cases, judicial activism
Public campaigns
Appeals/recourse to economic valuation of the environment
Demands for compensation for damage to health and contamination of soils
Environmental ImpactsVisible: Food insecurity (crop damage), Other Environmental impacts, Soil contamination, Surface water pollution / Decreasing water (physico-chemical, biological) quality, Groundwater pollution or depletion, Large-scale disturbance of hydro and geological systems
Potential: Loss of landscape/aesthetic degradation
OtherHeavy metals in crops, people and wild life
Health ImpactsVisible: Exposure to unknown or uncertain complex risks (radiation, etc…), Deaths, Other environmental related diseases, Other Health impacts, Mental problems including stress, depression and suicide, Occupational disease and accidents
OtherCadmium pollution
Socio-economic ImpactsVisible: Specific impacts on women, Violations of human rights, Increase in Corruption/Co-optation of different actors, Displacement, Loss of livelihood
Potential: Loss of traditional knowledge/practices/cultures, Land dispossession, Loss of landscape/sense of place
OtherCorruption alleged: the company influenced newspaper contents; also a top scientific expert in the court case of 1971, stated that the disease was caused by vitamin defficiency when before he himself had published articles in favour of the cadmium-pollution hypothesis (Kaji, 2012, p. 106).
Project StatusStopped
Pathways for conflict outcome / responseCompensation
Environmental improvements, rehabilitation/restoration of area
Court decision (victory for environmental justice)
Negotiated alternative solution
Strengthening of participation
Technical solutions to improve resource supply/quality/distribution
Withdrawal of company/investment
Development of AlternativesAfter many years, a Pollution Protection Agreement was concluded after the lawsuit, 1972, "a comprehensive agreement between victims, concerned residents, and the polluting company, allowing concerned residents to participate in decision making and pollution prevention and thus offering a long-term solution to industrial pollution. The experience itself is valuable because it exemplifies a rare case of successful pollution control in Japan." (Kaji, 2012).
Do you consider this as a success?Not Sure
Why? Explain briefly.The Mitsui company paid compensation after a court case. Land areas have been depolluted at great cost paid for by public authorities. Much damage was done for many years. There was a denial of facts for decades.
Sources and Materials

Preventative Measures Against Water Pollution Jinzu River, Toyama Prefecture (history of Kamioka mine and the cadmium pollution)
[click to view]

Background: Bret Walker, 2011, Toxic Archipelago. A History of Industrial Disease in Japan (one chapter on Itai Itai disease)

Background: The Political Economy of the Environment: The Case of Japan, by Shigeto Tsuru, UBC Press, 2000. One chapter on Itai Itai disease, one of the "Four Pollution Diseases" of Japan.

Economic costs of the Itai Itai disease, article in Environmental Economics and Policy Studies, Sept. 1999, Volume 2, Issue 3, pp 215–229, Itai-Itai disease and the countermeasures against cadmium pollution by the Kamioka mine, by Yoshida, F., Hata, A. & Tonegawa, H.
[click to view]

Masanori Kaji, Role of experts and public participation in pollution control: the case of Itai-itai disease in Japan, Ethics in Science and Env Politics, vol. 12, 2012 (outstanding analysis, trans. and edited from Japanese)
[click to view]

Masanori Kaji, 2015, Itai-itai disease: lessons from the way to environmental regeneration, chapter 7 in Y. Fujigaki ed. Lessons from Fukushima, Springer.
[click to view]

Japanese environmental policies since World War II.This is an updated and revised version of an article that originally appeared in The Keiei Kenkyu (Business Review), XXXV II, 5–6, January, 1987 by Ken'ichi Miyamoto, Capitalism, Nature, Socialism, 2(2), 1991: 71-100.
[click to view]

Margaret Mckean, Environmental Protests and Citizen Movements in Japan, Univ of California Press, Berkeley, 1981 (p. 45-50, good description)
[click to view]


Exposure to cadmium can cause cancer, harm kidneys, by R. Prasad. The Hindu, 10 August 2003.
[click to view]

Description of ceremonies on 50 anniversary of 1996, some commentaries by surviving victims
[click to view]

Map of cadmium pollution in Japan, and number of affected people
[click to view]

Other Documents

[click to view]

Other CommentsThere are connections between the various cases of industrial diseases in Japan. Thus (Kaji, 2012, p. 104) writes that in June 1965, patients with mercury poisoning disease were found in Niigata prefecture, a neighboring prefecture to the Toyama prefecture, and this was referred to as the second Minamata disease. Its victims and residents organized a victims’ association in August of the same year because they were unhappy with the belated action of the government. The association in Niigata filed a suit against Showa Denko, the responsible company, in June 1967, as

the first of the 4 major pollution-related lawsuits. Several members of the Itai-itai Disease Residents’ Association participated in the site inspection for the Niigata lawsuit in October 1967 and identified the need for another lawsuit against Mitsui because of the Itai Itai disease in Toyama prefecture.
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ContributorGrettel Navas & JMA
Last update28/11/2016