Minamata Mercury Poisoning (1950s)

Minamata Mercury Poisoning remains the worst industrial chemical catastrophe in Japanese history, with mercury levels in bay sediment reaching 600 parts per million. A Chisso Corporation factory dumped methylmercury into Minamata Bay from 1932 to 1968, poisoning fish that formed the local diet; over 2,265 victims were officially certified, but the true toll likely exceeds 10,000. This disaster killed more than 1,700 people directly and left thousands with lifelong neurological damage, outperforming #2 Bhopal in the duration and scope of environmental contamination.