An-naka zinc refinery and cadmium pollution, Japan

Cadmium contamination in An-naka since 1937. Lawsuit in 1969 and first court injunction in Japan against polluting metal refineries affecting agriculture and ecosystems caused by the Toho Zinc Co., Ltd.


A refinery run by the Toho Zinc Co., Ltd., which was established in 1937, discharged cadmium into the air and the river. In the following years, the impact was apparent and residents soon led an organized protest, complained about the destruction of their silkworm production as well as fish and agricultural production downstream. In the 1960s, TEPCO, which wanted to increase power supply to the refinery, logged communal forests without permission, leading to another level of environmental protest. In 1969, 309 residents with the help of 239 lawyers filed a claim in court asking for injunction to the refinery expansion, which was granted in the following month. This was the first injunction granted against the mineral refinery. In 1970, rice in An-naka was found to be contaminated with cadmium. A scientific study described the situation as follows: "In Annaka City, Gunma Prefecture, where the largest zinc refinery of Japan is located, about 200 samples of agricultural products, soil, silkworms, and excrement of the farmers were collected and analyzed to verify the environmental pollution by the refinery. As a result, it was found that the content of cadmium and other metals in mulberry leaves for silkworms and in wheat flour shows a remarkable relation to the distance from the refinery chimney, and further, that the content of cadmium and other metals is remarkably higher in leaf vegetables such as cabbages compared with root vegetables, fruit vegetables, or cereals. Thus, it was made clear that the hilly regions higher than the refinery, are polluted only by metal-containing air, while the lower rice field regions are affected by waste water, as well as, polluted air". (Kobayashi, J).

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Basic Data
NameAn-naka zinc refinery and cadmium pollution, Japan
ProvinceGunma prefecture
SiteAn-naka city
Accuracy of LocationHIGH local level
Source of Conflict
Type of Conflict (1st level)Industrial and Utilities conflicts
Type of Conflict (2nd level)Metal refineries
Specific CommoditiesZinc
Project Details and Actors
Project DetailsThe refinery and smelter were established in 1937 by the Toho Zinc company. Cadmium pollution of the environment in Japan

has occurred as contamination of agricultural land directly by fallout from aerial emission or indirectly by water transport of sludge in particulate form. An example of the former is in the case of Annaka City, Gunma Prefecture, and of the latter Jintsu (Jinzu) River basin, Toyama Prefecture, in which Itai-itai disease outbroke.
Type of PopulationSemi-urban
Start Date01/06/1937
End Date14/04/1991
Company Names or State EnterprisesToho Zinc Co., Ltd. from Japan - polluter
Tokyo Electric Power Company (TEPCO) from Japan
Relevant government actorsGunma prefecture government

Annaka City

Japan Ministry of Health and Welfare

Japan Ministry of International Trade and Industry (now Ministry of Economy, Trade and Industry)
Environmental justice organisations and other supportersJapan Young Lawyers Association

Local farmers
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 MobilizingFarmers
Industrial workers
Informal workers
Local government/political parties
Local scientists/professionals
Forms of MobilizationDevelopment of a network/collective action
Lawsuits, court cases, judicial activism
Official complaint letters and petitions
Public campaigns
Street protest/marches
Environmental ImpactsVisible: Air pollution, Biodiversity loss (wildlife, agro-diversity), Food insecurity (crop damage), Loss of landscape/aesthetic degradation, Soil erosion, Deforestation and loss of vegetation cover, Surface water pollution / Decreasing water (physico-chemical, biological) quality
Potential: Groundwater pollution or depletion
Health ImpactsVisible: Mental problems including stress, depression and suicide
Potential: Accidents, Occupational disease and accidents, Other environmental related diseases
OtherExposure to cadmium contaminated air, water, and agricultural products.
Socio-economic ImpactsVisible: Increase in Corruption/Co-optation of different actors, Displacement, Lack of work security, labour absenteeism, firings, unemployment, Loss of livelihood, Loss of traditional knowledge/practices/cultures, Violations of human rights, Land dispossession, Loss of landscape/sense of place
Project StatusIn operation
Pathways for conflict outcome / responseCompensation
Court decision (victory for environmental justice)
Negotiated alternative solution
Strengthening of participation
Do you consider this as a success?Yes
Why? Explain briefly.This is the first court injunction that was granted against metal refinery companies in Japan. The alternative dispute resolution was reached with condition of renewing agreement once in three years.
Sources and Materials

Land Expropriation Act, Japan


Accumulation of cadmium and other metals in organs of plants growing around metal smelters in Japan. Toyoaki Morishita & Jerzy K. Boratynski (1992). Soil Science and Plant Nutrition, 38:4, 781-785, DOI: 10.1080/00380768.1992.10416712

Industrial Emission of Cadmium in Japan, by Noboru Yamagata, Environmental Health Perspectives, Vol. 28, pp. 17-22, 1979

J. Kobayashi, Environ. Health; (United States); Journal Volume: 5; Conference: 5. annual conference on trace substances in environmental health, Columbia, MO, USA, 29 Jun 1971
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Background: Bret L. Walker, Toxic Archipelago. A history of industrial disease in Japan. University of Washington Press, Seattle, 2010.


Chronology of the history of the company Toho ZInc
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Other Documents

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Meta Information
ContributorKenichi Matsui, University of Tsukuba, kenichim(a)
Last update18/11/2016