was a

town A town is a type of a human settlement, generally larger than a village but smaller than a city. The criteria for distinguishing a town vary globally, often depending on factors such as population size, economic character, administrative stat ...

located in Higashikanbara District,

Niigata Prefecture is a Prefectures of Japan, prefecture in the Chūbu region of Honshu of Japan. Niigata Prefecture has a population of 2,131,009 (1 July 2023) and is the List of Japanese prefectures by area, fifth-largest prefecture of Japan by geographic area ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

. In 2003, the town had an estimated

population Population is a set of humans or other organisms in a given region or area. Governments conduct a census to quantify the resident population size within a given jurisdiction. The term is also applied to non-human animals, microorganisms, and pl ...

of 2,753 and a

population density Population density (in agriculture: Standing stock (disambiguation), standing stock or plant density) is a measurement of population per unit land area. It is mostly applied to humans, but sometimes to other living organisms too. It is a key geog ...

of 10.68 per km². The total area was 257.69 km². On April 1, 2005, Kanose, along with the town of Tsugawa, and the villages of Kamikawa and Mikawa (all from Higashikanbara District) were merged to create the town of Aga. In 1964, a chemical factory in the village released

methylmercury Methylmercury is an organometallic cation with the formula . It is the simplest organomercury compound. Methylmercury is extremely toxic, and its derivatives are the major source of organic mercury for humans. It is a bioaccumulative environment ...

into the

Agano River The is a river system in the Hokuriku region of Honshu, Japan. It is also called the Aga River or the Ōkawa River in Fukushima. It is designated as a Class A river. The source of the river is Mount Arakai on the border of Fukushima and Toc ...

and caused

Niigata Minamata disease is a neurological syndrome caused by severe mercury poisoning. Identical in symptoms to the original outbreak of Minamata disease in Kumamoto Prefecture, the second outbreak in Niigata Prefecture was confirmed with the same name in 1965. The dis ...

References

Dissolved municipalities of Niigata Prefecture Aga, Niigata {{Niigata-geo-stub