Medical Research into Minamata disease and their relationship to major events connected with the Disaster

By examining the history of Minamata disease and its different stages, we can see how investigations and other events connected with the disaster have changed over time.

1.1956 - 1960: From the Official Recognition of Minamata Disease to the Screening Council for Minamata Disease Patients:

• 1956: Research and study in Minamata started by Kumamoto University’s Department of Hygiene, Pediatrics, Internal Medicine, Pathology, and others.
• 1956～59: Haruhiko Tokuomi, Toru Okajima of Kumamoto University first internal medicine reported 34 examined patients of Minamata disease.
• 1960: Dr. Tokuomi participated in the Screening Council for Minamata Disease Patients. Between 1960 and 1981, Dr. Tokuomi had the symptom frequency lists, including follow-up data for 10 to 20 years, of some 30 cases published in 16 domestic medical periodicals.

2.1960 - 1965: From the Screening Council for Minamata Disease Patients to the Recognition of Niigata Minamata Disease:

• The number of patients certified by the Screening Council for Minamata disease patients from 1960 to 1965 was only 33.
• in March 1963, Dr. Tokuomi and Dr. Okajima propounded a theory that Minamata disease had ended in 1960 (Shinkei Kenkyu No Shinpo).

3.1965 - 1973: From Minamata Disease Recognition in Niigata to Mercury Panic:

• 1965: In the Agano River basin epidemiology investigation on Minamata disease in Niigata, Dr. Tadao Tsubaki of Niigata University included mild cases with only sensory disorders for Minamata disease certification.
• 1966: Dr. Tsubaki reported on the cases of Minamata disease in Niigata at a conference of the Japanese Society of Internal Medicine. Dr. Tokuomi made a remark about “non-legitimate Minamata disease applicants” at that time.
• 1968: Chisso finally stopped dumping polluted wastewater.
• 1969: The First Minamata disease lawsuit was filed.
• 1971: The Kumamoto Association of Doctors against Environmental Pollution was formed.
• 1972: Dr. Tsubaki spoke in favor about Minamata disease patients, “Doctors should examine mild cases and atypical cases properly without bias and shouldn’t decide the cause for psychosomatic or malingering disorder” (Kagaku (Japanese), October, 1972).

4.1973 - 1985: From Mercury Panic to Fukuoka High Court’s Judgment:

• 1971: Kumamoto University’s “Minamata Disease Study Group, 10 Years on” (commonly called “the Second Minamata Disease Study Group”) started their examination.
• May, 1973: Possibilities of a third Minamata disease was reported in the report of the Second Minamata disease Study Group, because of the existence of neurological findings in the control area. There were 49 caustic soda factories in Japan at that time, which used mercury. The whole of Japan was in a panic about the possibilities of being exposed to mercury poisoning.
• August, 1973: Dr. Tsubaki became the chairman of the Environmental Agency Expert Meeting and denied the existence of a third wave of Minamata disease. After this meeting, Dr. Tsubaki gradually lost interest in studying Minamata disease.
• January, 1974: The Minamata Clinic was established.
• 1974: An article indicating the change in Dr. Tsubaki’s attitude (Shinkei Kenkyu No Shinpo, October, 1974).
• 1975: Katsurajima investigation began.
• “1977 Judgment Criteria” adoption.
• 1978: Minamata Kyoritsu Hospital established.

5. 1985 - 1995 From the Second Minamata Disease Lawsuit’s Fukuoka High Court’s Verdict to “Political Settlement”:

• 1985: Fukuoka High Court in the Second Minamata disease lawsuit, recognized Minamata disease including cases with only sensory disorder.
• 1985: “The Medical Expert Meeting concerning Minamata Disease” supported 1977 Judgment Criteria
• 1989: Dr. Shukuro Araki’s (First Internal Medicine Department of Kumamoto University) investigation of nervous disorders of inhabitants in farm villages in Kumamoto prefecture showed “the sensory disorder of limb peripheral predominance is less than 1%”.
• The verdict in the Third Minamata Disease lawsuit.

6.1995 - 2004 From “Political Settlement” to the Supreme Court Judicial Decision:

• 1995: Minamata disease “political settlement”, involving many patients who had previously had their cases postponed or dismissed.
• Minamata disease Kansai Suit, plaintiff witness, Dr. Shigeo Ekino, defendant witness, Mitsuaki Eto.
• 1997～1999: the Sub-committee for Minamata Disease, Committee of Study and Human Rights in the Japanese Society of Psychiatry and Neurology investigated and criticized the 1977 Judgment Criteria and the conclusions of the 1985 Medical Expert Meeting for lack of medical evidence.
• 1999: Dr. Makoto Uchino collected data of people who had applied for Minamata disease certification, and revealed the reality of rejected people.
• 2001: Osaka High Court decided in favor of the patients who had brought the Minamata Disease Kansai Lawsuit to court in 1982.

7. 2004 - 2011 From the Supreme Court Judgment to the Present:

• 2004: The Supreme Court judgment recognized the responsibility of the Government in the Kansai Lawsuit. After the verdict was given, there were massive numbers of applications for certification of Minamata disease and other health measures.
• October 2005: the “No More Minamata” lawsuits were filed. Soon after that, they were brought before the court.
• July 2008 ～July 2009: Dr. Takaoka was cross-examined as a witness for the plaintiffs
• July 2009: Implementation of the Law Concerning Special Measures for Minamata Disease
• September 20～21, 2009: The Shiranui Sea Coastal Area Health Investigation. Various other Minamata disease investigations were started throughout Japan.
• January, 2010: The Government withdrew Fusako Usuki as a witness for the defence.
• February, 2010: Takaoka, as a witness for the plaintiffs, submitted written evidence arguing against Usuki’s opinions as expressed in a document, previously submitted by her.
• In 2011: Reconciliation was reached in the “No More Minamata lawsuit”. Lawsuits such as Mizoguchi lawsuit and the Minamata Disease Mutual-Aid Association lawsuit continue.