Minamata disease is Japan’s most widespread disease from pollution, with victims totaling over 2,200, just including registered patients. It came about as a result of industrial waste discharge, in the form of methylmercury, from a factory into the sea.

It is a methylmercury-induced disease that damages the cranial nerves after eating fish polluted by the accumulation of methylmercury contained in industrial effluent. A fetal Minamata disease also exists, in which unborn babies suffer from mercury poisoning via the placenta of pregnant women who have eaten polluted fish, etc., and whereby babies are born with a disorder similar to cerebral infantile paralysis. This is not an infectious disease that spreads through the air or food, and is not genetic. Minamata disease causes health damage due to environmental pollution and is the largest case of environmental pollution in human history in terms of the scale of damage and the significance of the destruction of the natural environment. From the occurrence of Minamata disease, people who once led peaceful lives with rich natural blessings, rapidly suffered and died from the disease. Many people suffer health damage from Minamata disease even now.