Uptake of ¹³¹I, ¹³⁴Cs and ¹³⁷Cs in tulip (Tulipa gesneriana L.) after the Fukushima Daiichi nuclear accident and their translocation from its above ground parts to the bulb

抄録

Radioiodine (¹³¹I) and radiocesium (¹³⁴Cs and ¹³⁷Cs) uptake through the above ground parts and transfer to the bulb of tulip (Tulipa gesneriana L.) was measured in April 2011, one month after the heavy depositions of radioactive materials. Plant samples were collected from a flower garden of J Village on April 20 and 28, 2011. Each sampled above ground parts was equally divided into two portions and one portion was washed with detergent including surfactant to remove dust from the surface and the other portion was unwashed as a control. The average retention factor after washing (activity concentration ratios after and before washing) for radioiodine and radiocesium were 0.97 and 0.58, which means more radioiodine was fixed on the plant surface. Activity of one sampled tulip bulb was measured and the concentration ratios between the bulb to the directly contaminated above ground parts were 0.03 for ¹³¹I and 0.47 for radiocesium. It was clear that radiocesium was more mobile than iodine in the plant.