Japanese scientists have some good news for farmers (and eaters) near the crippled Fukushima nuclear power plant: The soil can be made safe for planting.
After the meltdown that followed the devastating magnitude 9.0 Tohoku earthquake and resulting tsunami on March 11, radioactive isotopes of cesium escaped from the plant. With a half-life of up to 30 years, those particles threatened to turn Japanese cropland into wasteland for several generations.
But as Nature News reported Tuesday, researchers who have been monitoring the soil have found that the Fukushima radiation hasn’t penetrated very far. Most of the fallout is still within the top 2 inches of soil, according to Tomoko Nakanishi, a plant radiophysiologist at the University of Tokyo. The rain hasn’t washed that fallout away, and it hasn’t seeped into the groundwater, Nakanishi tells Nature News. If scooped up soon, the remaining soil is almost certainly safe for agricultural use.
Nakanishi's research team has also been studying wheat crops near the nuclear plant. The scientists have discovered that for the most part, the radioactive particles have accumulated on the surface of wheat plants. Plants whose leaves were open at the time of the disaster collected up to 1 million becquerels of radioactive cesium per kilogram – far above the 500 Bq/kg that is considered safe for people to eat. However, plants whose leaves opened after the worst of the radioactive emissions were found to have just 300 to 500 Bq/kg.