The Environment Ministry plans to propose changes to make it possible for people who suffer only from sensation disorders to be recognized as victims of the Minamata mercury-poisoning disease, officials said Friday.
Under the government’s criteria adopted in 1977, recognition of Minamata disease sufferers requires a combination of the disorder of sensation plus separate symptoms.
The ministry stopped short of a fundamental review of the 1977 criteria, but plans to make the changes in how victims are recognized with supplementary notes.
The ministry started to look into the 1977 standards after the Supreme Court in April last year posthumously recognized a woman as a Minamata disease sufferer even though she did not meet the criteria. She only suffered sensation disorder.
It was the first time the top court had ruled in favor of a person seeking recognition as a victim of the disease or their kin.
Minamata disease is one of the nation’s worst pollution-related illnesses. It took its name from Minamata Bay in Kumamoto Prefecture, where mercury-laced waste water was released by Shin-Nippon Chisso Hiryo K.K. in the 1950s and 1960s.
The company later changed its name to Chisso Corp.
In subsequent years, the disease was also reported from other areas of Japan.
Minamata disease paralyzes the human central nervous system and causes birth defects. The government recognized it as a pollution-caused disease in September 1968.
According to the officials, the ministry will soon notify Kumamoto, Kagoshima and Niigata prefectures as well as the city of Niigata about the changes in the recognition process.
Even if there is no combination of sensation disorders and other symptoms, the ministry could still recognize Minamata disease victims based on a comprehensive assessment of factors such as an individual’s intake of organic mercury, the officials said.