Update:April 1, 2010

(1) Initiation of Chisso's Plant Operation

1.Establishment of Chisso Co., Ltd. and Outbreak of Minamata Disease

Minamata City was a small town on the southern tip of Kumamoto Prefecture, facing Shiranui Sea (Yatsushiro Sea), a calm inland sea surrounded by Kyushu Island and the Amakusa Islands. The key industry of the city is fishery (See Figure 3-1). Around Minamata bay is a district richin marine products, enjoying spawning grounds and natural fishing reefs.
In 1908, Nippon Nitrate Fertilizer Co., Ltd., the predecessor of the present Chisso Co., Ltd. - renamed in January 1965; hereinafter referred to as "Chisso" - started its operation with the manufacture of curbide and lime nitrogen. Chisso has consistently expanded the range of products handled; it started manufacturing ammonia and ammonium sulfate in 1927 and introduced acetaldehyde process for acetic acid production in 1932. Having suspended its operation due to World War II, Chisso has resumed shortly after the end of the war to enlarge its production capacity to a greater scale.
In keeping with the growth of Chisso, Minamata has been developed to become one of the major industrial cities in Kumamoto Prefecture. Minamata, which used to be a village, was upgraded to a town in 1912 and then from a town to a city in 1949. The Chisso Minamata Plant gradually increased its importance in the local society, being influential in various aspects such as population, financial affairs and land use. The residents has then becomemore and more dependent upon the chemical manufacturer in their daily lives.
Meanwhile, polluted discharge from the plant has caused serious problems. In 1926, Chisso paid compensation money to a fishermen's cooperative association to indemnify for damages due to declining fish catch.
Furthermore, various abnormal phenomena were reported in and around Minamata Bay: shellfish perished, fishes died floating on their backs, and cats lost their lives in states of madness.