Minamata disease

Minamata disease is a toxic neurological disease that occurred among residents who routinely consumed seafood contaminated with methylmercury compounds discharged into the sea and rivers from chemical plants. The outbreak occurred along the Yatsushiro Sea coast, mainly around Minamata Bay in Kumamoto Prefecture, and was subsequently confirmed in the Agano River basin in Niigata Prefecture.

The first case of Minamata disease in the Minamata Bay area was reported in May 1956 (Showa 31), and since then the Kumamoto University School of Medicine has played a central role in investigating the cause and conducting research.

In Minamata disease, methylmercury contained in seafood was absorbed through the gastrointestinal tract. It is thought that 95-100% of the ingested methylmercury was absorbed. In the gastrointestinal tract, it is absorbed mainly by binding to cysteine. Methylmercury-cysteine conjugates taken up into the blood easily cross the cerebrovascular barrier. This is thought to be due to its structural similarity to methionine, an essential amino acid for humans.