E Minamata disease Q&A

1. Outbreak & Cause

Q4: How was the cause of Minamata disease revealed?

A4: It was demonstrated by a lot of research including studies on the patients, animal experiments, chemical analysis, etc.

At first, since the majority of the patients were fishermen who ate large amounts of marine products, and the neighboring cats also showed abnormalities, it was suspected that polluted fish might be a cause.
Later, the cause of Minamata disease was identified as methylmercury based on the findings such as: 1) the characteristic symptoms shown by the patients, 2) the detection of mercury in urine from the patients, 3) the experimental results of cats given methylmercury-contaminated food, and 4) detection of methylmercury in the wastewater of Chisso's factory.