minamata disaster

MINAMATA DISASTER

B.T.SIDHAARTH2013111118

Outline• The History(1908-1955)• 1956-1959

– Finding the cause/Identification of Mercury• 1959

– Compensation/waste water treatment• “Ten years of Silence”

– Continued pollution– Congenital Minamata Disease

• Mercury Poisoning and Control Response• Measures against Minamata Pollution

– The Water Pollution Control Law– Restoration of the Environment– Environmental Impact on Minamata Pollution

The History(1908-1955)

The History(1908-1955)• The Chisso Corporation opened a chemical factory in Minamata in

1908.• Minamata is a city located Kumamoto prefecture, Japan.• Chisso chemical factory initially produced fertilizers.• Following the nationwide expansion of Japan’s chemical industry, the

company branched out into the production of acetylene, acetaldehyde, acetiv acid, vinyl chloride and octanol.

• The Minamata factory became the most advanced in all of Japan.


•The rapid expansion of the Minamata factory spurred on the local economy.•Chisso prosperred, so did Minamata.•Chisso had great influence on Minamata.•In 1932, Chisso Minamata factory first started acetaldehyde production.

–Producing 210 tons per year.•By 1951, production had jumped to 6000 tons per year.

–Over half of japan’s total output.


• The chemical reaction used to produce the acetadehyde used mercury sulphate as catalyst.

• A side reaction of the catalytic cycle led to the production of methyl mercury.

• Methyl mercury is an organic mercury compound.• Methyl mercury is a highly toxic component.• Waste water from Chisso factory were released into Minamata Bay.

1956 - 1959

1956 - 1959

• April 21, 1956, a five year old girl was examined at Chisso’s factory

hospital in Minamata.

• Physicians were puzzled by her symptoms:

– Difficulty in walking, speaking and convulsions.

• Few days later, eight years old girl in the neighbourhood was found

experiencing the similar problrms.

• On May 1, 1956, discovery of an “epidemic of unknown disease of

the central nervous system” was reported to the local public health.

• Patients were isolated – leading to stigmatization and discrimination.

1956 - 1959• Cats were also seen to have convulsions,

go mad and die.– This disease in cats were commonly called

as dancing cat fever.• Crows fell from the sky.• Fishes floated dead on the sea shore.• The Kumamoto University Research Group

was formed.• The disease developed without prior

warning.• Patients lost sensation, and complained of

numbness in hands and feet.• By October, 1956, 40 patients were

discovered(14 dead).

1956 - 1959

• The researchers figured the following:• Staple food of the victims were fish and shellfish from Minamata

Bay.• Food poisoning by heavy metals.• Initially, manganese was thought to be the cause substance.• British neurologist Douglas McAlpine suggested the Minamata

symptoms resembled to those of organic mercury.• Focus of investigation shifted and centered mercury.

1956 - 1959

• In February, 1959, mercury distribution in Minamata Bay was investigated.

• Large quantities of mercury detected in fishes from the bay.• The highest concentration centered around the factory wastewater

canal in Hyakken harbour.

1956 - 1959

• Hair samples of victims and Minamata residents were taken for test.

• The maximum mercury level recorded was 705 ppm.

• This compared to to an average level of 4 ppm for non – minamata

residents.

1959

• Chisso came under close scrutiny.• In order to deflect criticism, wastewater route was changed.• It discharged waste water directly into Minamata river.• Now victims began to appear in other fishing villages up and down

the coast of the Shirauni Sea.

1959

• Chisso did not co-operate with the Kumamoto Research Team.

• Withheld information on its industrial processes.

• Chisso factory’s hospital director, Hajime Hosokawa carried out his

own experiment on Minamata disease.

• He confirmed that it was organic mercury poisoning.

• The company did not reveal the result to the investigators.

• The company orederd Hosokawa to stop the research.

1959• Compensation for fishermen and patients.• The agreements were formulated outside the legal system by ad-

hoc mediation committees.• Final agreements were weighed in favor of Chisso.• Punitive clauses in the agreements include:

“Representative groups of fishermen and Minamata disease patients could not make future claims for compensation against the company”.

1959WASTEWATER TREATMENT SYSTEM• On October, 21, Chisso was ordered to switch back its wastewater

drainage to Hyakken Harbour.• Installed a cyclator purification system with a special ceremony.• Chisso’s president drank a glass of water supposedly treated to

demonstrate it was safe.• But wastewater from acetaldehyde plant still contained mercury.• Deception that company’s wastewater has been made safe.• In people’s, the issue of Minamata disease was resolved…

1959 – 1969

Ten years of silence

1959 - 1969

• The period between the first set of agreements in 1959 to the first

legal action taken against Chisso in 1969 are is called as the “Ten

years of silence”

• By late 1960, the Kumamoto and Kagoshima perfectural

government continued a joint survey in the hairs of the people living

around the Shiranui sea.

• Results showed that organic mercury had spread all around the

inland sea.

1959 - 1969

CONTINUED POLLUTION

• Contaminated fish still poisoned people.

• 50 ppm of mercury in people’s hair were discovered.

• Highest recorded level was 920 ppm

• The perfectural government did not publish the results, nor did

anything in response to the survey.

• A follow-up study ten years later discovered that many had died

from “unknown causes”

1959 - 1969CONGENITAL MINAMATA DISEASE• Local doctors noticed for a long time an

abnormal high frequency of cerebral palsy.

• A re-examination of children diagnosed with cerebral palsy was carried out.

• The symptoms of the children closely mirrored those of adult Minamata disease patients.

• However, many of their mothers did not exhibit symptoms.

• After several years of study and autopsy of two children, the doctors diagnosed an unrecognized congenital form of Minamata disease.

1959 - 1969

OFFICIAL GOVERNMENT RECOGNITION

• On 26 September 1968, the government finally issued an official conclusion as to the cause of Minamata disease.

“Minamata disease is a disease of the central nervous system, a poisoning caused by long-term consumption, in large amounts, of fish and shellfish from Minamata Bay. The causative agent is methylmercury. Methylmercury produced in the acetaldehyde acetic acid facility of Shin Nihon Chisso's Minamata factory was discharged in factory wastewater... Minamata disease patients last appeared in 1960, and the outbreak has ended. This is presumed to be because consumption of fish and shellfish from Minamata Bay was banned in the fall of 1957, and the fact that the factory had waste-treatment facilities in place from January 1960."

Mercury poisoning

Mercury poisoning

• Methyl mercury compound, a inorganic compound which is highly toxic.

• It is a bi-product during the production of mercury sulphate.

Mercury cycle

Mercury poisoning

Methylmercury is absorbed 100% into the system through the intestines with oral intake.

Mercury poisoning

SYMPTOMS OF MINAMATA DISEASE

GENERAL• Muscle weakness• Damage to hearing, vision and speech• Crippling hands and feet

EXTREME CASES• Paralysis• Coma • Death

Measures against Minamata pollution

Measures against Minamata Pollution

• Temporal variations in acetaldehyde production.• Final shut down of pollutant sources, by total circulation system

adopted in 1966.


Effluent Control

• Drainage of the Chisso’s factory effluent (containing methylmercury)

to Minamata Bay got regulated.

• In 1970, “Water Pollution Control Law” was enacted.

• The law enforced control of discharge of effluent in all water areas in

Japan, in relation to toxic substances.

• Conversion of production method was advised against caustic soda

plants that might discharge mercury.


The Water Pollution Control Law

The objective of the law is to:

• Prevent pollution of water in the public water areas.

• Regulate effluent discharge by factories into public water areas.

• Protect human health and preserve the living environment.

• Protect sufferers, by incorporating provisions for compensation for

damages.


Restoration of the Environment

• Bottom Sludge treatment

program.

• Reclamation and dredging.

• Mercury concentration reduced to

4.69 ppm.

Summary

Summary

Root cause Assessment of Minamata Pollution

• Indiscriminate dumping of wastewater.

• Absence of wastewater treatment facility.

• Economic clout of Chisso Corporation.

• Government apathy about the severity of the disease.

Summary

Environmental Impact of Minamata Pollution

• Huge quantities of Mercury detected in fish and shellfish in

Minamata Bay.

• Ecology of the Minamata Bay was severely affected.

• Dredging and reclamation done to remove toxic sludge from the

Minamata Bay.

Summary

Economic Impact of Minamata Pollution

• Drastic drop in fishing sales, causing loss of livelihood.

• Joblessness leading to high poverty rate.

• Compensation leaves Chisso Corporation in huge debt.

Summary

Social Impact of Minamata pollution

• Stigmatization and discrimination against patients.

• Negative image – “The city of Pollution”

• Riot and social unrest.

• Social awareness about the disease.

Minamata PhotoGallery

In Japanese, “Chisso” means nitrogen.Pouring its wastes into the air as well as waters, the

Chisso chemical complex dominates the city of Minamata.

Waste chemicals dumped into the bay, worked their way up the food chain to the people of the city and caused the Minamata Disease.

Here, fishing on the bay of Minamata. This scene has changed very little over the centuries. However, the pollution has changed the relationship that the people of Minamata had with the sea and fishes.

Chisso’s president Shimada, performed Japanese ritual of shame and apology by touching his forehead on the ground.

Signing of agreement between Patients’ association and Chisso

People demonstrate with photos of the dead on the last day of the trial in October of 1972

References

• Fumikazu Yoshida (2006) “Environmental restoration of Minamata: New thinking brings new advances”. Integrated research system for Sustainability Science and Springer, 2:85 – 93.

• Ministry of the Environment, Government of Japanhttp://www.env.go.jp/en/

• SOSHISHA, The Supporting Centre For Minamata Diseasehttp://soshisha.org/english/index_e.htm

• http://en.wikipedia.org/wiki/Minamata_disease

http://www.env.go.jp/en/

http://soshisha.org/english/index_e.htm

http://en.wikipedia.org/wiki/Minamata_disease

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