Kazue Tazaki is a professor emeritus at Kanazawa University in Ishikawa Prefecture. She took the contaminated soil from Iitate-mura in Fukushima Prefecture where the villagers were required to evacuate, and grew rice using that soil.
Rice planting and growing was banned in Iitate-mura this year.
Professor Tazaki just harvested the rice, and measured the concentration of cesium-137. The result?
From the rice grains: 2,600 becquerels/kg
From the straw: 2,200 becquerels/kg
From the roots: 1,500 becquerels/kg
Soil contamination: 50,000 becquerels/kg
Roughly an equal amount of cesium-134 is to be expected. The transfer rate of cesium-137 in this case was about 0.05.
From Toyama Shinbun, local paper in Ishikawa Prefecture (9/27/2011):
Kazue Tazaki, professor emeritus at Kanazawa University has compiled the result of her experiment of growing rice using the soil from Iitate-mura in Fukushima Prefecture where high radiation levels have been recorded. 2,600 becquerels/kg of radioactive cesium was detected from the harvested rice, more than 5 times the provisional safety limit (500 becquerels/kg) set by the national government. It was prohibited to plant rice in Iitate-mura because of the Fukushima I Nuclear Power Plant accident. The professor's data will be extremely valuable in studying the effect of radiation in the soil on the agricultural crops.
Professor Tazaki collected the soil from the rice paddies in Nagadoro District of Iitate-mura, area with very high radiation, when she visited Fukushima Prefecture in late June. At her home in Kanazawa City, she planted the seedlings of "Koshihikari" which were germinated in Tawara-machi in Kanazawa City on the soil from Iitate-mura.
She harvested the rice in mid September, had it analyzed at a laboratory in Fukui Prefecture for cesium-137 in various parts of the rice and calculated the radiation levels per kilogram. The highest cesium-137 concentration of 2,600 becquerels/kg was found in (unprocessed) rice, 2,200 becquerels/kg from the straw, and 1,500 becquerels/kg from the roots. 50,000 becquerels/kg was detected from the soil itself.
To compare, "Koshihikari" rice planted in the rice paddies in Tawara-machi was also analyzed but no radioactive materials were detected at all.
Professor Tazaki says, "I myself was very shocked to find that the edible part of the rice had the most radiation. The decontamination of the soil should be carried out as soon as possible". She will teach farmers in Minami Soma City in Fukushima on a decontamination method using diatomite unique to Ishikawa Prefecture.
Professor Tazaki found a bacterium that absorbs radioactive materials like uranium and thorium in Tanzania earlier this year, where she taught geology after she retired from Kanazawa University in 2009.
Her result makes me very suspicious of the results announced by Fukushima Prefecture. Iitate-mura does have high soil contamination but it is by no means the highest. Judging by the rice hay contamination there are many other locations within Fukushima that may have radiation levels just as high and still grow rice because they lie outside the 30 kilometer radius from the plant. And yet the prefectural government says it's found 500 becquerels/kg of radioactive cesium at most from one location, and the rest is below 200 becquerels/kg.
It is also possible that the professor scraped the top soil only, whereas farmers in Fukushima tilled deeper and thus mixing the highly contaminated soil in the top 5 centimeters with the uncontaminated soil below, lowering the overall radiation.
Well, despite the official ban with the threat of fines, the rice grew in Iitate-mura after all as at least one farmer spread the seed rice directly in the rice paddies. And as this Iitate-mura villager tweets, the rice has grown better than ever with far less work and resources. Why not test that too for radiation, instead of cutting it down?