This year marked the 50th anniversary of the official recognition of Minamata disease, a symbol of postwar industrial pollution in Japan. But the episode of massive organic mercury poisoning is not a thing of the past. On Aug. 11, a group of 100 people who have not been officially recognized as sufferers of the disease filed a lawsuit against the central government, four prefectural governments and Chisso Corp., seeking 850 million yen in damages, or 8.5 million yen for each.

They make up a sixth group of plaintiffs in a continuing lawsuit, bringing the total number of plaintiffs to more than 1,000. An additional 4,300 people have applied to local governments for official recognition as Minamata disease victims. So there are many more potential plaintiffs.

A report on Minamata disease, submitted by an experts' forum to then Environment Minister Yuriko Koike on Sept. 19, said it is urgent that the central government take the initiative in establishing a new, permanent framework to aid all Minamata disease victims, including unrecognized and latent victims. The government should heed the proposal and put it into effect as soon as possible.