Minimata Disease,HISTORY, DEFINITION, PATHOGEN, EPIDEMIOLOGY, SYMPTOMS, Treatment, Official government recognition.

 HISTORY :

Minimata is a city located in Kumamoto Prefecture, Japan.

Minimata was established as a village in 1889 then grew into a city in 1949.

The Chisso Corporation first opened a chemical factory in Minimata in 1908. Initially producing fertilizers but as the company grew larger.They started manufacturing acetaldehyde to produce plastics. In process of manufacturing, methylmercury were used.

⏩  April 21, 1956, a 5 year-old girl was examined at the Chisso Corporation's factory hospital in Minimata, Kumamoto. • The physicians were puzzled by her symptoms: difficulty walking, difficulty speaking, and convulsions.

Days later, her younger sister and their neighbor's daughter also began experiencing similar problems. After a house-to-house investigation, 8 more patients were discovered and hospitalized. 

May 1956, the hospital director reported to the local public health office the discovery of an "epidemic of an unknown disease of the central nervous system“, marking the official discovery of Minimata disease.

DEFINITION :

Minimata Disease is also known as “Chisso-Minimata disease”, it is a disease of the central nervous system, a mercury poisoning caused by consumption in large amounts, of fish and shellfish from Minimata Bay.

PATHOGEN :

The causative agent is methylmercury produced in the acetaldehyde acetic acid.

EPIDEMIOLOGY :

Full epidemiological study has never been conducted and patients were recognized only if they voluntarily applied to a certification council to seek financial compensation. 

 Over 17,000 people from Kumamoto and Kagoshima prefectures have applied for certification as Minamata disease victims. Of these, 2,264 victims have been officially certified (1,408 of whom have died) and over 10,353 people have received financial compensation from Chisso. Therefore, 12,617 people have been officially recognized as patients affected by mercury.

SYMPTOMS : 

1. Ataxia (lack of muscle coordination on voluntary movements) .

2. Numbness in hands and feet • 

3. Loss of peripheral vision .

4. Damage to hearing and speech.

5. In extreme cases, insanity, paralysis, coma, and death follow within weeks of the onset of symptoms. 

6. A congenital form of the disease can also affect foetuses in the womb.

Treatment to Minamata Disease •

No fundamental cure for Minamata disease has yet been discovered, so treatment consists of attempts to lessen the symptoms • 

The most important aspect of treatment is the removal of mercury from the body using chelating agents. • 

Official government recognition •

September 26, 1968, 12 years after the discovery of the disease, the government issued an official conclusion that cause of Minimata disease is the causative agent methylmercury produced in the acetaldehyde acetic acid facility of Shin Nihon Chisso's Minamata factory was discharged in factory wastewater.”

Syed Basharat