The sleepy fishing village of Minamata, Japan, 1956: and the neighbourhood cats have gone mad. They claw, scratch, and scream, sometimes breaking into convulsions before dropping dead. Then something more serious happens. Physicians are baffled by a 5-year-old girl who has trouble walking and talking. Her suite of symptoms is like nothing the medics have seen before. Two days’ later, the girl’s sister develops the same symptoms – and other cases quickly follow.
We now know that the cause was mercury poisoning: the metal, in an organic form called methylmercury that is particularly easily absorbed by the body, had been released into the sea by local industry and accumulated in fish and shellfish. Minamata disease has since claimed about 2000 lives.