A follow-up study ten years later discovered that many had died from "unknown causes". Congenital Minamata disease
Local doctors and medical officials had noticed for a long time an abnormally high frequency of cerebral palsy and other infantile disorders in the Minamata area. In 1961, a number of medical professionals, including Masazumi Harada (later to be honored by the United Nations for his body of work on Minamata disease), set about re-examining children diagnosed with cerebral palsy. The symptoms of the children closely mirrored those of adult Minamata disease patients, but many of their mothers did not exhibit symptoms. The fact that these children had been born after the initial outbreak and had never been fed contaminated fish also led their mothers to believe they were not victims. At the time the medical establishment believed the placenta would protect the foetus from toxins in the bloodstream, which is indeed the case with most chemicals. What was not known at the time was that exactly the opposite is the case with methylmercury: the placenta removes it from the mothers bloodstream and concentrates the chemical in the foetus. After several years of study and the autopsies of two children, the doctors announced that these children had an as-yet unrecognised congenital form of Minamata disease. The certification committee convened on 29 November 1962 and agreed that the two dead children and the sixteen children still alive should be certified as patients, and therefore liable for "sympathy" payments from Chisso, in line with the 1959 agreement.
Today
Minamata disease remains an important issue in contemporary Japanese society. Lawsuits against Chisso and the prefectural and national governments are still continuing and many regard the government responses to date as inadequate. The companys "historical overview" in its current website makes no mention of their role in the mass contamination of Minamata and the dreadful aftermath. Their 2004 Annual Report, however, reports an equivalent of about US$50 million (5,820 million yen) in "Minamata Disease Compensation Liabilities". From 2000 to 2003, the company also reported total compensation liabilities of over US$170 million. Their 2000 accounts also show that the Japanese and Kumamoto prefectural governments waived an enormous US$560 million in related liabilities. Their FY2004 and FY2005 reports refer to Minamata disease as "mad hatters disease", a term coined from the mercury poisoning experienced by hat-makers of the last few centuries (cf. Erethism).A memorial service was held at the Minamata Disease Municipal Museum on 1 May 2006 to mark 50 years since the official discovery of the disease. Despite bad weather, the service was attended by over 600 people, including Chisso chairman Shunkichi Goto and Environment Minister Yuriko Koike.On Monday, March 29, 2010, a group of 2,123 uncertified victims reached a settlement with the government of Japan, the Kumamoto Prefectural government, and Chisso Corporation to receive individual lump-sum payments of 2.1 million yen and monthly medical allowances.Most congenital patients are now in their forties and fifties and their health is deteriorating.