著者

渡辺 伸一

出版者

奈良教育大学

雑誌

奈良教育大学紀要. 人文・社会科学 (ISSN:05472393)

巻号頁・発行日

vol.56, no.1, pp.115-125, 2007-10-31

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Environmental cadmium pollution causes cadmium poisoning. The first cadmium-polluted area ever discovered in the world was the Jinzu River basin in Toyama Prefecture in Japan. The most severe case of cadmium poisoning is Itai-itai disease (osteomalacia), which was officially recognized as a pollution-related disease by the Japanese government in 1968, and a less severe case is tubular kidney dysfunction. In other words, the occurrence of Itai-itai disease is only the "tip of the iceberg". The tubular kidney dysfunction is the earliest and most prevalent adverse result of chronic cadmium poisoning. The Japan Public Health Association Cadmium Research Committee, supported by the Environmental Agency, carried out health surveys in cadmium-polluted areas of 8 prefectures during the period of 1976-1984 and reported that many cases of tubular kidney dysfunction were found not only in Toyama but also in Ishikawa, Hyogo and Nagasaki prefectures. However, the Environmental Agency and the research committee have never certified this kidney dysfunction as a pollution-related disease. In 1970, the Japanese government set tentative acceptable standards of 1ppm for brown rice and enacted the Agricultural Land Soil Pollution Prevention Law in 1971. Based on this Law, restoration projects of polluted soils of rice paddies were started. If cadmium nephropathy was certified as a officially pollution-related disease, acceptable standards for brown rice must be more strict than 1ppm, because 1ppm is a standard to prevent habitants from suffering from Itai-itai disease. This new strict standard arrives at increases in polluted rice and soils. This means increases in the expenses to buy polluted rice and to restore polluted soils. To offer indemnity to farmers for any reduction in his rice crop is the responsibility of polluting industries and to pay expenses to restore polluted soils is the responsibility of polluting industries, the central government and local authorities. This paper concludes that the main reason why cadmium nephropathy has not been certified as an official pollution- related disease is that the decision-making of the Environmental Agency and the research committee reflects the intention of the polluting industries and the government who regard the expenses above as too heavy a burden.