Fifty years have passed since the first official recognition of Minamata disease, a major symbol of Japan's postwar industrial pollution. Yet relief for those who suffered massive organic mercury poisoning, dating back to the 1950s and '60s, has not been fully delivered. More than 3,700 people have filed application with local governments for official recognition as Minamata disease patients and some 1,000 others have filed lawsuits against the state and Chisso Corp., which released the pollutant into the environment. This means that nearly 5,000 people are waiting for some kind of decision that will compensate them for their suffering. The government must break the deadlock soon.

Minamata disease paralyzes the central nervous system and causes such symptoms as persistent headaches, mental confusion, limb paralysis, walking difficulties and convulsions. Minamata disease first appeared after methyl mercury was released by chemical maker Shin-Nippon Chisso Hiryo K.K., the predecessor of Chisso Corp., into Minamata Bay in Kumamoto Prefecture. Methyl mercury is waste from the process to produce acetaldehyde, a plasticizing agent. Many people who ate fish contaminated with organic mercury developed the disease. Some people were born with the disease.

As of the end of March, 2,955 people in Kumamoto, Kagoshima and Niigata prefectures had been officially recognized as patients of the disease, and 2,009 of them have already died, according to the Environment Agency. Some 15,000 others have applied for recognition but to no avail. Experts familiar with the disease estimate that the real number of latent sufferers is probably much larger, reaching several tens of thousands.