Editorial: Minamata disease lawsuit decision shows Japan has long way to go to help victims

The Kumamoto District Court has dismissed a damages lawsuit filed by 144 plaintiffs against the Japanese state and the prefectures where they lived plus Chisso Corp. over Minamata disease, a condition caused by methylmercury poisoning from a Chisso factory. While rejecting the suit itself on the grounds that it was filed after the exclusion period, which extinguishes the right to claim damages after 20 years from the unlawful act, the court did acknowledge 25 of the plaintiffs as Minamata disease victims.

This ruling shows that the pursuit of relief for Minamata disease, considered the first pollution-related disease to emerge in Japan, is not over.

Under Japan’s Minamata disease special relief law that went into force in 2009, those eligible for aid are generally limited to individuals who resided in the nine cities and towns along the Shiranui coast in west Kyushu for one year or more. Twenty of the 25 plaintiffs recognized by the court as Minamata disease sufferers lived outside this designated area. This means that patients needing relief have been left out in the cold, despite the government aiming for a “final resolution” to the problem through the law.

A key point of contention in the lawsuit was how to determine the exclusion period. The government argued that symptoms should have appeared by 1973, five years after Chisso ceased discharging wastewater contaminated with methylmercury, and that the right to claim compensation thus expired in 1993.

However, there were local circumstances making people hesitant to come forward due to fear of discrimination. The plaintiffs argued that the calculation should start from when a person is diagnosed with Minamata disease.

In contrast to the Kumamoto District Court ruling, a judgment by the Osaka District Court in September last year fully accepted the residents’ claims and recognized all 128 plaintiffs as eligible for relief.

A total of 45,933 people have applied for one-time payments from Kumamoto and Kagoshima prefectures under measures based on the special relief law. The national and prefectural governments requested proof that the claimants had consumed seafood from along the Shiranui coast, and 9,572 people were ultimately deemed ineligible for aid. Sorting relief applicants this way has delayed the resolution of Minamata disease’s legacy.

The special relief law stipulates that the government should actively and promptly conduct health surveys in the region to grasp what damage has been done. However, the survey methods remain undecided, as does the timing of the surveys themselves.

Lawsuits related to Minamata disease continue in the Niigata and Tokyo district courts, and the plaintiffs are aging. Many have passed away during court proceedings.

The principle underpinning the special relief law is to “provide aid to the fullest extent possible.” The government and the Diet should explore ways to achieve comprehensive relief.