Transfer factors of Sr-90 and Cs-137 from soil to the sweet potato collected in Taiwan

The activity concentrations of Sr-90 and Cs-137 in sweet potatoes collected at eight locations in Taiwan were measured using radiochemical analysis an d gamma-ray spectrometry. Sr-90 is found to be more concentrated in leaves than in storage roots (the mean activity ratio of storage roots to leaves i s 0.55), while Cs-137 distributes homogeneously in both storage roots and l eaves (the corresponding ratio for Cs-137 is 0.94). The mean transfer facto rs of Sr-90 and Cs-137 from soil-to-storage roots are determined to be 0.55 and 0.095, respectively, while the mean transfer factors of Sr-90 and Cs-1 37 from soil to leaves are 1.38 and 0.105, respectively. The effective dose equivalent values due to the dietary intake of Sr-90 and Cs-137 through sw eet potato for the Taiwanese are estimated to be 9.38 x 10(-8) and 2.37 x 1 0(-8) Sv yr(-1), respectively. (C) 1999 Elsevier Science Ltd. All rights re served.