Authorities trying to decontaminate radioactive soil in the aftermath of the accident at the Fukushima No. 1 nuclear power plant have found that sunflowers, despite their reputation for absorbing radioactive cesium, have little effect, an experiment has shown.

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The experiment on removing radioactive cesium started in May in farmland totaling 7,000 square meters in Iitatemura and other locations in Fukushima Prefecture.

In the experiment, the effects of the following four methods were examined: scraping away surface soil; washing contaminated soil with water and removing the water; burying topsoil and replacing it with subsoil; and using sunflowers and other plants to absorb radioactive cesium in soil.

The results showed the least effective of the four methods was the use of plants.