Japanese town, site of an ecological disaster 1953–56, where 43 people died after eating fish poisoned with dimethyl mercury. The poison had been released as effluent from a local plastics factory, and became concentrated in the flesh of sea organisms. Many townspeople suffered long-terms effects, including paralysis, tremors, paralysis and brain damage.
The mercury was released as a stable mercury compound but was converted to methyl mercury by anaerobic bacteria in the sediments at the bottom of the bay.