Tragedy of Toyama Prefecture

More than 1000 years ago in central Japan local miners began to extract precious metals. During the centuries gold, lead, silver, and copper were extracting from the Kamioka mine of Toyama Prefecture.

In 1904-1905, the Russo-Japanese War broke out; another 10 years later, Japan entered the First World War. The country badly needed metals, especially in zinc - for making armor, aircraft, and ammunition. Approximately at this time, as early as the 1910s, first cases of an unknown disease were recorded, which affected local peasants who came to the doctor and complained of severe pain in the bones and joints.

Until the second half of the 1940s, the cause of the illness of the inhabitants of the prefecture could not be explained and attributed to either a natural focal disease or an unknown bacterial infection. Initially supposed the cause of the disease was called lead poisoning, as several kilometers upstream there was a lead-ore mine. Only in 1955 Dr. Noboru Hagino and colleagues suggested that a strange disease can be caused by chronic poisoning with cadmium salts.

Cadmium compounds are highly toxic: after absorption in blood they affect the central nervous system, liver, and kidneys, disrupt the phosphorus-calcium metabolism. Chronic poisoning leads to anemia and destruction of bones. Cadmium is a carcinogen: it easily accumulates in rapidly multiplying cells (for example, in cancer tumors). It also inhibits the activity of a number of enzymes, disrupts phosphorus-calcium metabolism, disrupts the metabolism of microelements (Zn, Cu, Fe, Mn, Se).

In the course of a comprehensive investigation, it was found that for the cleaning of zinc mined in Kamioke, miners kilned it and boiled it in acid, removing cadmium. According to the habits of that time, they poured the formed cadmium suspension directly to the ground. From there, cadmium penetrated into the groundwater, and then into the local Jinzu River and its tributaries.

photo by Toukou Sousui 淙穂鶫箜

Thus, cadmium salts accumulated in the body of the inhabitants of Toyama prefecture, who for a long time consumed seafood caught from the river, and rice from the fields irrigated by the Jinzu waters. The disease that struck the Japanese got the name "itai-itai" (translated from Japanese as "it hurts-it hurts"). Since 1964, more than 180 people have been recognized as sick.
In recent years, people have become concerned that after years, materials related to this disease will be lost and that this problem will not be known to future generations. In this regard, in April 2012, the Itai-itai Disease Museum was opened, which is located in Toyama Prefecture Toyama.