176
are shown in Fig. 10. For both crops, even if ess U values were two or more times
higher than init U values in soil samples ( ess U/ init U > 2), the TF values did not differed
from the low ess U case ( ess U/ init U < 0.5) by t-test. Therefore, we could conclude that
the newly added U by phosphate fertilizer was not more bioavailable than initially
existing U in the soil. The results indicated that in the soil-to-crop environment, U
from radioactive disposal sites and init U will behave similarly. Thus, we can use TF
values of U obtained from field studies for long-term dose assessment.
Fig. 9 Correlations between U in crops and total U or ess U in agricultural soil samples
Fig. 10 Comparison between TFs of high and low ess U/ init U concentration ratios in soil samples
K. Tagami and S. Uchida
are shown in Fig. 10. For both crops, even if ess U values were two or more times
higher than init U values in soil samples ( ess U/ init U > 2), the TF values did not differed
from the low ess U case ( ess U/ init U < 0.5) by t-test. Therefore, we could conclude that
the newly added U by phosphate fertilizer was not more bioavailable than initially
existing U in the soil. The results indicated that in the soil-to-crop environment, U
from radioactive disposal sites and init U will behave similarly. Thus, we can use TF
values of U obtained from field studies for long-term dose assessment.
Fig. 9 Correlations between U in crops and total U or ess U in agricultural soil samples
Fig. 10 Comparison between TFs of high and low ess U/ init U concentration ratios in soil samples
K. Tagami and S. Uchida