A1: Not all of them will develop Minamata disease.

Commentary:
Minamata disease occurred among people who had continued to eat a lot of fish containing large amounts of methylmercury over a long period.
Their symptoms varied with the mercury content and the amount of the polluted fish consumed as well as with the sensitivity of the individuals to methylmercury.
Although trace amounts of methylmercury exist in the environment and is found in fish, there is no fear of developing Minamata disease from eating them.