Minamata sufferers in Japan keep up their fight for compensation, 50 years after poisoning
Fifty years since the outbreak, Niigata residents are still battling for recognition of their disease and for compensation for industrial poisoning
It began when Keiji Kanda's cat performed a "crazy dance" and died in a convulsive frenzy. Then Kanda himself fell sick, sometimes shaking so violently it would take several members of his family to hold him still.
"His neck would go rigid and his entire body trembled," recalls his son Sakae, 87, who also struggled with similar ailments, including numbness in his neck and shoulders and acute dizzy spells. "The doctors … had no idea what it was."
On June 12, 1965, the cause became clear when Niigata University Hospital professor Tadao Tsubaki announced what he had suspected for months.
Villages along the Agano River in Niigata Prefecture, 350km north of Tokyo, had been hit by Minamata disease - a form of mercury poisoning that attacks the central nervous system.
The source of the poisoning emerged two years later when Niigata officials discovered mercury-laced effluent had been released into the Agano River from chemical engineering company Showa Denko's plant in Kanose, around 17km upstream from Kanda's village.
Like the industrial poisoning incident in Minamata, a bay in the southwest island of Kyushu where Japan's first outbreak had occurred nine years earlier, high concentrations of methylmercury were detected in fish and other marine life.