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Yokkaichi asthma, Japan

In Yokkaichi city, many cases of asthma were reported after power stations, oil refining and petrochemical plants were put in operation after 1955. A court case was won by plaintiffs in 1972; this is one of the Big Four Pollution Diseases.


Yokkaichi is a city with the largest population in Mie Prefecture. This was the location of one of the four big pollution diseases of Japan. This one lasted from the mid 1950s to the early 1970s. The burning of petroleum and crude oil caused large quantities of sulfur oxide, a smog began to cover some quarters of the city resulting in severe cases of chronic obstructive pulmonary disease, chronic bronchitis, pulmonary emphysema, and bronchial asthma. Yokkaichi is an industrial city and faces Ise Bay on the Pacific Ocean side of the Japanese archipelago. During World War II, naval fuel factories were constructed in the southern part of Yokkaichi Harbor, but were destroyed by bombing before they began to operate. In the mid 1950s, a petroleum complex was built and began to operate around the remnant of this facility. The complex included the largest heavy oil-fired power station and refinery in Japan at that time. As this complex used crude oil with a high sulfur content (more than 3%) and did not employ suitable measures for desulfurization, the sulfur dioxide (SO2) emissions caused air pollution with an increased concentration of sulfur oxides, as high as 1 ppm in the polluted areas. By early 1960s, the incidence of respiratory diseases, including bronchial asthma, increased among people living in the vicinity of the complex, and this subsequently became a major health problem in Japan, that was known as Yokkaichi Asthma(Yokkaichi Zensoku, in Japanese). At Isozu, where air pollution was most severe, incidence of asthma reached up to 2.5% of total population in 1964.  A series of counter measures based on an area-wide total emission control system were taken since 1972, as a result of a successful lawsuit brought by nine inhabitants of Isozu against six companies in the Yokkaichi Court, for reparations of health damage caused by air pollution. The court case began on 1st September 1967, a favorable verdict was obtained on 24 July 1972. Sulfur oxide air pollution in this region has been afterwards markedly reduced. Deemed as one of the Four Big Pollution Diseases of Japan, Yokaikaichi Asthma was felt in the city  for nearly 20 years, after Yokkaichi filled in its coastal lowlands in a successful bid to attract modern industries, especially chemical processing, steel production, and oil  refining. In 1959 it began 24-hour operations. Although citizens took pride in the growing industrial complex, it is said that their enthusiasm waned when air pollution and noise pollution created grave human health problems.

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Basic Data
Name of conflict:Yokkaichi asthma, Japan
Accuracy of locationMEDIUM (Regional level)
Source of Conflict
Type of conflict. 1st level:Industrial and Utilities conflicts
Type of conflict. 2nd level:Oil and gas refining
Specific commodities:Crude oil
Chemical products
Petrochemical industry
Project Details and Actors
Project details

After 1955 the air over areas in Yokkaichi villages became severely

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Level of Investment:8,000,000,000
Type of populationUrban
Affected Population:180,000
Start of the conflict:1955
Company names or state enterprises:Chubu Denryoku from Japan
Mitsubishi Monsanto Kasei from Japan
Mitsubishi Yuka from Japan
Mitsibishi Kase Kogyo from Japan
Ishihara Sangyo from Japan
Showa Yokkaichi from Japan
Relevant government actors:Ciy of Yokkaichi
Mie Prefecture
Mie University
Environmental justice organizations (and other supporters) and their websites, if available:Local union of civil service workers.
Yokkaichi Kogai to Tatakau Shiminhei no Kau (Society of Citizen Soldiers to fight Yokkaidi Pollution), founded in 1971.
Conflict & Mobilization
IntensityHIGH (widespread, mass mobilization, violence, arrests, etc...)
Reaction stageIn REACTION to the implementation (during construction or operation)
Groups mobilizing:Industrial workers
Trade unions
Local scientists/professionals
Fisher people
Forms of mobilization:Creation of alternative reports/knowledge
Development of a network/collective action
Development of alternative proposals
Lawsuits, court cases, judicial activism
Media based activism/alternative media
Official complaint letters and petitions
Public campaigns
Street protest/marches
Hunger strikes and self immolation
Two victims of the disease committed suicide in 1966 and 1967 to call attention to their plight.
Environmental ImpactsVisible: Air pollution, Noise pollution, Surface water pollution / Decreasing water (physico-chemical, biological) quality
Potential: Loss of landscape/aesthetic degradation, Soil contamination, Groundwater pollution or depletion
Health ImpactsVisible: Other environmental related diseases, Mental problems including stress, depression and suicide, Deaths, Exposure to unknown or uncertain complex risks (radiation, etc…)
Other Health impactsAsthma and pulmonary diseases caused by sulphur oxides
Socio-economical ImpactsVisible: Loss of livelihood, Violations of human rights
Potential: Displacement
Other socio-economic impactsStrong impact on children.
Project StatusStopped
Conflict outcome / response:Compensation
Institutional changes
Court decision (victory for environmental justice)
Negotiated alternative solution
Technical solutions to improve resource supply/quality/distribution
Development of alternatives:Desulfurization technologies have been important in reducing sulfur emissions. It involves passing sulfur-containing flue gas (by-product of petrochemical production) through a sulfur dioxide absorber or scrubber.
Do you consider this an environmental justice success? Was environmental justice served?:Not Sure
Briefly explain:It took a long time (nearly twenty years) for the court case to be won, some compensation paid, and for measures to stop pollution to be implemented.
Sources & Materials
References to published books, academic articles, movies or published documentaries

Mortality and life expectancy of Yokkaichi Asthma patients, Japan: Late effects of air pollution in 1960–70s. Peng Guo, Kazuhito Yokoyama, Masami Suenaga and Hirotaka Kida. Environmental Health, 2008. doi: 10.1186/1476-069X-7-8
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Margaret A. McKean, Environmental Protest and Citizen Politics in Japan, Univ of California Press, Berkeley 1981
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Shigeto Tsuru, The Political Economy of the Environment. The case of Japan, Bloomsbury, London, 1999.

Civil Society and the New Civic Movements in Contemporary Japan: Convergence, Collaboration, and Transformation, by Simon Andrew Avenell. Journal of Japanese Studies, 35, 2009.
[click to view]

Pollution-related injury in Japan: On the impact of the four major cases, by Yoshihiro Nomura. Environmental Law and Policy, 1(4), February 1976.
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Links to general newspaper articles, blogs or other websites

Pollution disappears from Yokkaichi city, by Khonesavanh Latsaphao (reporting on a visit in 2016 to the Pollution Museum in Yokkaichi)
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The Yokkaichi Asthma, March 17, 2015 / SHARON XINYI
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Last update27/11/2016
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