Q3: Did Minamata disease occur in other places as well as Yatsushiro Sea coast?

A3: Niigata Minamata disease, the second outbreak of Minamata disease, occurred in the Agano River basin of Niigata Prefecture.

Commentary:
A similar disease occurred in the Agano River basin in 1965, 12 years after the first official reporting of Minamata disease,
This was caused by methylmercury that was discharged in the wastewater of the Kanose factory of Showa Denko K.K..
These two outbreaks of Minamata disease are included among the four largest outbreaks of pollution-related diseases, together with Yokkaichi asthma and Itai-Itai disease.