Itai-itai disease was found in the cadmium(Cd) polluted Jinzu River basin in Toyama Prefecture, and has been generally recognized since the 1950's by the effort of inhabitants and Dr. Hagino who was a general practitioner with a private clinic in the polluted area.

Itai-itai disease was officially recognized in 1968 as the first disease induced by environmental pollution in Japan after legal proceedings. The basis of the court decision is simply but clearly shown in "The view of the Ministry of Health and Welfare" which consisted of 7 articles and was announced on 8th May, 1968. Especially, the basis that concluded the cause of the disease to be Cd pollution was epidemiological evidence that only cadmium can explain the limited development of itai-itai disease in a specific area around parts of the Jinzu River.


The degree of Cd pollution in different parts of the endemic area determined by the analyzed Cd concentration of the soil in the paddy fields was shown in Fig.1. In Fig.2, the frequency of the disease is illustrated by the percentage of women over 50 years of age having or suspected of having the disease. The striking correlation between the prevalence of itai-itai disease and degree of Cd pollution was found even within the endemic area.

Fig.1  The difference of degree of Cd
pollution in the parts of the
endemic area.
     Fig.2  Prevalence of itai-itai disease
in the women over 50 years of age.