The most rigid lessons obtained from Minamata disease are as follows: On the ground of scientific
disputes about decision of the pollution source and the causative factor for the disease, it took 12 years for
the Governmental policy to have been politically and socially decided, because the relations in the
competence among ministries and offices also became a difficulty in the decision, and pollution and
damages spread during the period, inducing further outbreaks of the second Minamata disease.