Minamata disease was named after a fishing port on the island of Kyushu where it was discovered in 1956. Chisso Corp. had been dumping methyl mercury directly into the bay since before World War II, but sharp increases in production in the early 1950s increased the flow of contaminating effluent. People and animals that ingested contaminated fish and shellfish suffered varying degrees of neurological damage. The polluting was not stopped until 1968 because the company, with the government's complicity, denied and tried to cover up its role in creating one of Japan's worst environmental disasters, one that became symbolic of the costs of relentless pursuit of economic growth.

The author is a doctor from Niigata, where a similar outbreak occurred in 1965 due to dumping of methyl mercury by Showa Denko into the Agano River. Saito played a key role in diagnosing and treating patients and pushing for accountability. The highly toxic compound contaminated the river fish and caused severe mercury poisoning — nearly 700 residents in Niigata are certified as suffering from Minamata disease, with a range of symptoms including general tiredness, numbness at the extremities, ataxia (gross lack of muscle coordination) and impaired speech, hearing and vision. As in Minamata, the outbreak in Niigata was first observed among cats living close to the river that appeared to go mad and move spastically before dying.

Saito recounts how, despite Showa Denko's efforts to lay a false trail and divert attention from its responsibility, local doctors, prefectural authorities and citizen's organizations mobilized to pinpoint the cause of the outbreak. In 1966 the Ministry of Health and Welfare traced the toxic waste to a Showa Denko factory in Kanose village. We read about how Showa Denko tried to discredit the evidence against it, and how it tried to lay blame with local farmers for agricultural chemical runoff after a 1964 earthquake. Saito recalls how Showa Denko planted evidence to implicate the farmers (which was quickly discredited by local police) and asserts that the central government initially tried to whitewash the findings of local researchers.