A ceremony Saturday in Toyama marked the completion of a 33-year project to restore cadmium-contaminated local farmland, which caused one of the four worst pollution-related diseases in Japan's postwar industrial boom.
Soil on 863 hectares of land in the Jinzu River basin has been replaced under the ¥40.7 billion project, which began in 1979.
Although this has allowed farmers to grow rice anywhere on the riverside, there are concerns that the lessons learned from itai-itai disease, which damages people's kidneys and softens their bones, are starting to fade.
The disease was caused by cadmium released upstream by Mitsui Mining & Smelting Co.'s Kamioka mine in Gifu Prefecture. The malady became Japan's first recognized pollution disease in 1968, and only four of its 196 victims are still alive.
The restoration work may also provide clues on how to decontaminate soil tainted by radioactive fallout from the nuclear crisis at the Fukushima No. 1 power plant.
The project, which was financed by the government, Mitsui Mining and prefectural governments, has reduced cadmium levels in unpolished rice to an average of 0.08 to 0.09 parts per million, compared with the safety standard of 0.4 ppm.
